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Trusses Problems with Solutions: A Comprehensive Guide
Introduction:
Are you facing frustrating issues with your trusses? Whether you're a homeowner noticing sagging ceilings or a construction professional dealing with structural defects, truss problems can be significant headaches. This comprehensive guide dives deep into common truss issues, explaining their causes, and providing practical solutions to help you rectify the situation. We'll cover everything from minor repairs to major structural concerns, equipping you with the knowledge to tackle these challenges head-on. Let's get started!
Common Truss Problems and Their Causes
Understanding the root cause of a truss problem is the first step towards effective repair. Here are some of the most frequently encountered issues:
1. Sagging or Drooping Trusses:
This is a visually obvious problem, often indicating a weakness within the truss system. Several factors can contribute:
Overloading: Exceeding the truss's designed load capacity, whether from added weight on the roof (heavy snow, excessive insulation), or improper storage in the attic, can cause sagging.
Defective Manufacturing: Errors during the manufacturing process, such as incorrect cuts or weak lumber, can lead to structural instability.
Settlement of Foundation: Uneven settling of the foundation can transfer stress unevenly onto the trusses, resulting in sagging.
Wood Decay or Insect Infestation: Damage caused by rot, termites, or other pests compromises the structural integrity of the wood, leading to sagging.
2. Cracking or Splitting of Lumber:
Cracks and splits in the truss members are a serious concern, signifying potential structural weakness. Causes include:
Improper Drying: Using lumber with insufficient drying can cause shrinkage and cracking after installation.
Overloading: Similar to sagging, overloading can stress the wood beyond its limits, resulting in cracking.
Exposure to Moisture: Prolonged exposure to moisture can weaken the wood and lead to cracking and splitting.
3. Improper Connections:
Weak or incorrect connections between truss members compromise the overall stability of the system.
Poor Nail Placement: Incorrect nail placement or insufficient nails can result in weak connections.
Damaged Connectors: Metal connectors can become damaged or corroded over time, reducing their effectiveness.
4. Trusses Misaligned or Out of Square:
Misaligned trusses indicate problems during installation, often leading to uneven roofline and structural instability.
Improper Installation: Errors during installation, such as incorrect placement or alignment, are the most common causes.
Foundation Issues: As mentioned earlier, foundation settlement can contribute to misalignment.
Solutions to Common Truss Problems
Now that we've identified the common problems, let's explore the solutions:
1. Addressing Sagging Trusses:
Reduce Load: Remove unnecessary weight from the roof (remove excessive insulation, clear snow).
Support Beams: Install temporary support beams to alleviate stress and prevent further sagging while planning for a more permanent solution.
Truss Repair or Replacement: Depending on the severity, repairs may involve reinforcing weak points or complete truss replacement. Consult a structural engineer for evaluation.
2. Repairing Cracks and Splits:
Minor Cracks: Small cracks can sometimes be addressed with wood epoxy or sealant.
Major Cracks or Splits: Extensive damage usually requires replacing the affected member.
3. Fixing Improper Connections:
Reinforce Connections: Use additional nails or stronger connectors to strengthen weak points.
Replace Damaged Connectors: Replace corroded or damaged connectors with new ones.
4. Correcting Misalignment:
Minor Misalignment: Small misalignments might be correctable through minor adjustments.
Significant Misalignment: Extensive misalignment usually requires professional intervention, potentially involving partial or complete truss replacement.
When to Call a Professional
While some minor repairs can be handled by homeowners with appropriate skills, it’s crucial to consult a qualified structural engineer or contractor for:
Significant Sagging: Any significant sagging warrants professional assessment to determine the underlying cause and necessary repairs.
Extensive Cracking or Splitting: Major structural damage requires the expertise of a professional to ensure safety and structural integrity.
Suspected Foundation Issues: If you suspect foundation problems contributing to truss issues, consult a foundation specialist.
Conclusion
Addressing truss problems promptly and effectively is vital for maintaining the structural integrity of your home or building. Understanding the common causes and implementing the appropriate solutions, whether through DIY repairs or professional intervention, ensures a safe and stable structure. Remember to prioritize safety and don't hesitate to call in the experts when necessary.
FAQs
1. How much does truss repair cost? The cost varies greatly depending on the extent of damage, the required repairs (simple reinforcement or complete replacement), and your location. Get multiple quotes from qualified contractors.
2. Can I DIY truss repairs? Minor repairs, like reinforcing connections or applying epoxy, might be manageable for experienced DIYers, but major repairs should be left to professionals.
3. How often should trusses be inspected? Regular inspections, ideally during routine home maintenance checks, can help identify potential problems early on.
4. What are the signs of a failing truss system? Sagging, cracking, splitting, misalignment, and noticeable creaking or popping sounds are all warning signs.
5. How long do trusses typically last? With proper maintenance and avoidance of overloading, engineered wood trusses can last for decades, but their lifespan depends on various factors, including environmental conditions and material quality.
trusses problems with solutions: Aerospace Structures and Materials Yucheng Liu, 2016-10-07 This comprehensive volume presents a wide spectrum of information about the design, analysis and manufacturing of aerospace structures and materials. Readers will find an interesting compilation of reviews covering several topics such as structural dynamics and impact simulation, acoustic and vibration testing and analysis, fatigue analysis and life optimization, reversing design methodology, non-destructive evaluation, remotely piloted helicopters, surface enhancement of aerospace alloys, manufacturing of metal matrix composites, applications of carbon nanotubes in aircraft material design, carbon fiber reinforcements, variable stiffness composites, aircraft material selection, and much more. This volume is a key reference for graduates undertaking advanced courses in materials science and aeronautical engineering as well as researchers and professional engineers seeking to increase their understanding of aircraft material selection and design. |
trusses problems with solutions: Problems and Solutions in Engineering Mechanics S. S. Bhavikatti, A. Vittal Hegde, 2009-05-30 Each chapter begins with a quick discussion of the basic concepts and principles. It then provides several well developed solved examples which illustrate the various dimensions of the concept under discussion. A set of practice problems is also included to encourage the student to test his mastery over the subject. The book would serve as an excellent text for both Degree and Diploma students of all engineering disciplines. AMIE candidates would also find it most useful. |
trusses problems with solutions: Structural Analysis Felix F. Udoeyo, 2019-11-27 Structural Analysis by Felix Udeyo is intended to teach students the methods and techniques for the analysis of structures. A sound knowledge of structures is a prerequisite for their proper design and ensures the structural integrity of civil engineering infrastructural systems. This textbook is comprised of three parts. The first part consists of an overview of structural analysis and introduces several structural loadings that may be considered during the analysis and subsequent design of structures. The second part covers classic methods of the analysis of determinate structures. The final section discusses classic methods for the analysis of indeterminate structures as well as methods for the analysis and construction of influence lines for indeterminate structures.This textbook is designed for upper-level undergraduates studying civil engineering, construction engineering and management, and architecture. It is also useful for construction professionals seeking licensure in their field of practice.An enhanced edition of this textbook is available on the Press's Manifold platform: https://temple.manifoldapp.org/projects/structural-analysis |
trusses problems with solutions: Stresses in simple trusses. 3. ed Mansfield Merriman, Henry Sylvester Jacoby, 1888 |
trusses problems with solutions: Structural Mechanics: Modelling and Analysis of Frames and Trusses Karl-Gunnar Olsson, Ola Dahlblom, 2016-01-26 Textbook covers the fundamental theory of structural mechanics and the modelling and analysis of frame and truss structures Deals with modelling and analysis of trusses and frames using a systematic matrix formulated displacement method with the language and flexibility of the finite element method Element matrices are established from analytical solutions to the differential equations Provides a strong toolbox with elements and algorithms for computational modelling and numerical exploration of truss and frame structures Discusses the concept of stiffness as a qualitative tool to explain structural behaviour Includes numerous exercises, for some of which the computer software CALFEM is used. In order to support the learning process CALFEM gives the user full overview of the matrices and algorithms used in a finite element analysis |
trusses problems with solutions: Structural Analysis Bryant G. Nielson, Jack C. McCormac, 2017-02-28 When teaching structural analysis, some contend that students need broad exposure to many of the classical techniques of analysis, while others argue that learners benefit more from the computer-based analysis experiences that involve parametric studies. Structural Analysis, Understanding Behavior strikes a balance between these viewpoints. Students may no longer need to know every classical technique but they still need a fundamental knowledge of the concepts which come from studying a subset of classical techniques. This foundation is then strengthened by the use of structural analysis software in activities designed to promite self-discovery of structural concepts and behaviors. This text was developed with this goal in mind. |
trusses problems with solutions: Structural Analysis Jack C. McCormac, 2006-10-13 Presenting an introduction to elementary structural analysis methods and principles, this book will help readers develop a thorough understanding of both the behavior of structural systems under load and the tools needed to analyze those systems. Throughout the chapters, they'll explore both statically determinate and statically indeterminate structures. And they'll find hands-on examples and problems that illustrate key concepts and give them opportunity to apply what they've learned. |
trusses problems with solutions: Fundamentals of Structural Analysis, 2nd Edition Roy, Sujit Kumar & Chakrabarty Subrata, 2003 For B.E./B.Tech. in Civil Engineering and also useful for M.E./M.Tech. students. The book takes an integral look at structural engineering starting with fundamentals and ending with compurter analysis. This book is suitable for 5th, 6th and 7th semesters of undergraduate course. In this edition, a new chapter on plastic analysis has been added.A large number of examples have been worked out in the book so that students can master the subject by practising the examples and problems. |
trusses problems with solutions: Building Structures James E. Ambrose, 1993 Construction Details From Architectural Graphic Standards Eighth Edition Edited by James Ambrose A concise reference tool for the professional involved in the production of details for building construction, this abridgement of the classic Architectural Graphic Standards provides indispensable guidance on standardizing detail work, without having to create the needed details from scratch. An ideal how to manual for the working draftsperson, this convenient, portable edition covers general planning and design data, sitework, concrete, masonry, metals, wood, doors and windows, finishes, specialties, equipment, furnishings, special construction, energy design, historic preservation, and more. Construction Details also includes extensive references to additional information as well as AGS’s hallmark illustrations. 1991 (0 471-54899-5) 408 pp. Fundamentals of Building Construction Materials And Methods Second Edition Edward Allen A thoughtful overview of the entire construction industry, from homes to skyscrapers…there’s plenty here for the aspiring tradesperson or anyone else who’s fascinated by the art of building. —Fine Homebuilding Beginning with the materials of the ancients—wood, stone, and brick—this important work is a guide to the structural systems that have made these and more contemporary building materials the irreplaceable basics of modern architecture. Detailing the structural systems most widely used today—heavy timber framing, wood platform framing, masonry loadbearing wall, structural steel framing, and concrete framing systems—the book describes each system’s historical development, how the major material is obtained and processed, tools and working methods, as well as each system’s relative merits. Designed as a primer to building basics, the book features a list of key terms and concepts, review questions and exercises, as well as hundreds of drawings and photographs, illustrating the materials and methods described. 1990 (0 471-50911-6) 803 pp. Mechanical and Electrical Equipment for Buildings Eighth Edition Benjamin Stein and John S. Reynolds The book is packed with useful information and has been the architect’s standard for fifty years. —Electrical Engineering and Electronics on the seventh edition More up to date than ever, this reference classic provides valuable insights on the new imperatives for building design today. The Eighth Edition details the impact of computers, data processing, and telecommunications on building system design; the effects of new, stringent energy codes on building systems; and computer calculation techniques as applied to daylighting and electric lighting design. As did earlier editions, the book provides the basic theory and design guidelines for both systems and equipment, in everything from heating and cooling, water and waste, fire and fire protection systems, lighting and electrical wiring, plumbing, elevators and escalators, acoustics, and more. Thoroughly illustrated, the book is a basic primer on making comfort and resource efficiency integral to the design standard. 1991 (0 471-52502-2) 1,664 pp. |
trusses problems with solutions: Computer Aided Design of Mechanical Systems United States. Army Materiel Command, 1973 |
trusses problems with solutions: Advanced Methods of Structural Analysis Igor A. Karnovsky, Olga Lebed, 2021-03-16 This revised and significantly expanded edition contains a rigorous examination of key concepts, new chapters and discussions within existing chapters, and added reference materials in the appendix, while retaining its classroom-tested approach to helping readers navigate through the deep ideas, vast collection of the fundamental methods of structural analysis. The authors show how to undertake the numerous analytical methods used in structural analysis by focusing on the principal concepts, detailed procedures and results, as well as taking into account the advantages and disadvantages of each method and sphere of their effective application. The end result is a guide to mastering the many intricacies of the range of methods of structural analysis. The book differentiates itself by focusing on extended analysis of beams, plane and spatial trusses, frames, arches, cables and combined structures; extensive application of influence lines for analysis of structures; simple and effective procedures for computation of deflections; introduction to plastic analysis, stability, and free and forced vibration analysis, as well as some special topics. Ten years ago, Professor Igor A. Karnovsky and Olga Lebed crafted a must-read book. Now fully updated, expanded, and titled Advanced Methods of Structural Analysis (Strength, Stability, Vibration), the book is ideal for instructors, civil and structural engineers, as well as researches and graduate and post graduate students with an interest in perfecting structural analysis. |
trusses problems with solutions: Mechanics of Materials Roy R. Craig, Jr., Eric M. Taleff, 2020-08-04 The fourth edition of Mechanics of Materials is an in-depth yet accessible introduction to the behavior of solid materials under various stresses and strains. Emphasizing the three key concepts of deformable-body mechanics—equilibrium, material behavior, and geometry of deformation—this popular textbook covers the fundamental concepts of the subject while helping students strengthen their problem-solving skills. Throughout the text, students are taught to apply an effective four-step methodology to solve numerous example problems and understand the underlying principles of each application. Focusing primarily on the behavior of solids under static-loading conditions, the text thoroughly prepares students for subsequent courses in solids and structures involving more complex engineering analyses and Computer-Aided Engineering (CAE). The text provides ample, fully solved practice problems, real-world engineering examples, the equations that correspond to each concept, chapter summaries, procedure lists, illustrations, flow charts, diagrams, and more. This updated edition includes new Python computer code examples, problems, and homework assignments that require only basic programming knowledge. |
trusses problems with solutions: Simplified Nonlinear Analysis of Large Space-trusses and Space-frames, Using Explicitly Derived Tangent Stiffnesses and Accounting for Local Buckling Kunihiro Kondoh, K. Tanaka, Satya N. Atluri, 1985 Simplified finite element methods for finite deformation, post-buckling analysis of large space trusses and space frames are presented. Arbitrarily large rigid translations and rigid rotations of each member are accounted for. Each 3-D truss member is assumed to withstand an axial force, while each 3-D frame member is assumed to withstand two bending moments, a twisting moment, and transverse and axial forces at each node. The influence of local (member) buckling on global instability is systematically examined. For both 3-D truss and frame members, explicit tangent stiffness matrices are derived. By 'explicit;' it is meant that no element-wise basis functions are assumed and that no element-wise numerical integrations are involved. These explicit tangent stiffness matrices are very simply evaluated at any point in the load deformation history of a space truss, or space frame, undergoing large deformations, as well as in the post-buckled region of behavior of these structures. An arc-length method is implemented to trace the post-buckling behavior of these large space structures. A large number of examples are included to: (1) bring out the economy as well as accuracy of the simplified method developed; (2) indicate the effectiveness of the present method in creating reduced-order models of large space structures; and (3) delineate the process whereby the overall behavior of the structure can be vastly improved by controlling the deformation of individual members through active or passive mechanisms. Keywords: Reduced order model; Simplified nonlinear analysis; Finite deformations; Finite rotations; Semi-tangential rotations; Exact tangent stiffness matrix; LSS (Large Space Structure) control; Arc-length method. |
trusses problems with solutions: MATLAB Codes for Finite Element Analysis A. J. M. Ferreira, 2008-11-06 This book intend to supply readers with some MATLAB codes for ?nite element analysis of solids and structures. After a short introduction to MATLAB, the book illustrates the ?nite element implementation of some problems by simple scripts and functions. The following problems are discussed: • Discrete systems, such as springs and bars • Beams and frames in bending in 2D and 3D • Plane stress problems • Plates in bending • Free vibration of Timoshenko beams and Mindlin plates, including laminated composites • Buckling of Timoshenko beams and Mindlin plates The book does not intends to give a deep insight into the ?nite element details, just the basic equations so that the user can modify the codes. The book was prepared for undergraduate science and engineering students, although it may be useful for graduate students. TheMATLABcodesofthisbookareincludedinthedisk.Readersarewelcomed to use them freely. The author does not guarantee that the codes are error-free, although a major e?ort was taken to verify all of them. Users should use MATLAB 7.0 or greater when running these codes. Any suggestions or corrections are welcomed by an email to ferreira@fe.up.pt. |
trusses problems with solutions: Structural Analysis 1 Salah Khalfallah, 2018-08-14 Using a general approach, this book supports the student to enable mastery of the methods of analysis of isostatic and hyperstatic structures. To show the performance of the methods of analysis of the hyperstatic structures, selected beams, gantries and reticular structures are selected and subjected to a comparative study by the different methods of analysis of the hyperstatic structures. |
trusses problems with solutions: Seismic Analysis of Structures T. K. Datta, 2010-03-16 While numerous books have been written on earthquakes, earthquake resistance design, and seismic analysis and design of structures, none have been tailored for advanced students and practitioners, and those who would like to have most of the important aspects of seismic analysis in one place. With this book, readers will gain proficiencies in the following: fundamentals of seismology that all structural engineers must know; various forms of seismic inputs; different types of seismic analysis like, time and frequency domain analyses, spectral analysis of structures for random ground motion, response spectrum method of analysis; equivalent lateral load analysis as given in earthquake codes; inelastic response analysis and the concept of ductility; ground response analysis and seismic soil structure interaction; seismic reliability analysis of structures; and control of seismic response of structures. Provides comprehensive coverage, from seismology to seismic control Contains useful empirical equations often required in the seismic analysis of structures Outlines explicit steps for seismic analysis of MDOF systems with multi support excitations Works through solved problems to illustrate different concepts Makes use of MATLAB, SAP2000 and ABAQUAS in solving example problems of the book Provides numerous exercise problems to aid understanding of the subject As one of the first books to present such a comprehensive treatment of the topic, Seismic Analysis of Structures is ideal for postgraduates and researchers in Earthquake Engineering, Structural Dynamics, and Geotechnical Earthquake Engineering. Developed for classroom use, the book can also be used for advanced undergraduate students planning for a career or further study in the subject area. The book will also better equip structural engineering consultants and practicing engineers in the use of standard software for seismic analysis of buildings, bridges, dams, and towers. Lecture materials for instructors available at www.wiley.com/go/dattaseismic |
trusses problems with solutions: Handbook of Research on Predictive Modeling and Optimization Methods in Science and Engineering Kim, Dookie, Sekhar Roy, Sanjiban, Länsivaara, Tim, Deo, Ravinesh, Samui, Pijush, 2018-06-15 The disciplines of science and engineering rely heavily on the forecasting of prospective constraints for concepts that have not yet been proven to exist, especially in areas such as artificial intelligence. Obtaining quality solutions to the problems presented becomes increasingly difficult due to the number of steps required to sift through the possible solutions, and the ability to solve such problems relies on the recognition of patterns and the categorization of data into specific sets. Predictive modeling and optimization methods allow unknown events to be categorized based on statistics and classifiers input by researchers. The Handbook of Research on Predictive Modeling and Optimization Methods in Science and Engineering is a critical reference source that provides comprehensive information on the use of optimization techniques and predictive models to solve real-life engineering and science problems. Through discussions on techniques such as robust design optimization, water level prediction, and the prediction of human actions, this publication identifies solutions to developing problems and new solutions for existing problems, making this publication a valuable resource for engineers, researchers, graduate students, and other professionals. |
trusses problems with solutions: Shape and Layout Optimization of Structural Systems and Optimality Criteria Methods G.I.N. Rozvany, 2014-05-04 Shape and layout optimization represent some of the most useful but also most difficult classes of problems in structural design, which have been investigated in detail only during the last few years. Shape optimization is concerned with the optimal shape of boundaries of continua or of interfaces between two materials in composites. Layout optimization deals with the simultaneous optimization of the topology, geometry and cross-sectional sizes of structural systems. In spite of its complextiy, layout optimization is a very rewarding task, because it results in much greater savings than the optimization of cross-sectional sizes only. Because of their important role in shape and layout optimization, the book also covers in detail new optimality criteria methods, which are capable of handling many thousand design variables and active design contraints. Shape and layout optimization is becoming an indispensable tool in the design of aeroplanes, space structures, cars, ships, building and civil engineering structures, power stations, chemical plants, artificial organs, sporting equipment, and all other solid systems where stresses and deformations play an important role. |
trusses problems with solutions: Algorithm-Driven Truss Topology Optimization for Additive Manufacturing Christian Reintjes, 2022-02-01 Since Additive Manufacturing (AM) techniques allow the manufacture of complex-shaped structures the combination of lightweight construction, topology optimization, and AM is of significant interest. Besides the established continuum topology optimization methods, less attention is paid to algorithm-driven optimization based on linear optimization, which can also be used for topology optimization of truss-like structures. To overcome this shortcoming, we combined linear optimization, Computer-Aided Design (CAD), numerical shape optimization, and numerical simulation into an algorithm-driven product design process for additively manufactured truss-like structures. With our Ansys SpaceClaim add-in construcTOR, which is capable of obtaining ready-for-machine-interpretation CAD data of truss-like structures out of raw mathematical optimization data, the high performance of (heuristic-based) optimization algorithms implemented in linear programming software is now available to the CAD community. |
trusses problems with solutions: Planar Trusses Mikhail Kirsanov, 2019-06-10 This text contains 73 schemes of statically definable trusses, including girder trusses, frames and arched trusses, solutions for many of which have not been widely published. Among these, it is possible to separately distinguish trusses with externally hidden but dangerous properties. The book will appeal to both practical engineers and theorists of structural mechanics. It provides a number of compact and easily reproducible formulas that can be used both as a test and as reliable additions to numerical calculations. These formulas are especially effective for trusses with a large number of panels, where numerical calculations are either inaccurate or require considerable counting time. |
trusses problems with solutions: A Text-book on Roofs and Bridges: Stresses in simple trusses. 4th ed. enl. 1898 Mansfield Merriman, 1890 |
trusses problems with solutions: Applied Statics and Strength of Materials Leonard Spiegel, George F. Limbrunner, Craig T. D'Allaird, 2021 The seventh edition of Applied Statics and Strength of Materials presents an elementary, analytical, and practical approach to the principles and physical concepts of statics and strength of materials. It is written at an appropriate mathematics level for engineering technology students, using algebra, trigonometry, and analytic geometry. An in-depth knowledge of calculus is not required for understanding the text or solving the problems-- |
trusses problems with solutions: Finite Element Computations in Mechanics with R Khameel Bayo Mustapha, 2018-04-17 Finite Element Computations in Mechanics with R: A Problem-Centred Programming Approach provides introductory coverage of the finite element method (FEM) with the R programming language, emphasizing links between theory and implementation of FEM for problems in engineering mechanics. Useful for students, practicing engineers, and researchers, the text presents the R programming as a convenient easy-to-learn tool for analyzing models of mechanical systems, with finite element routines for structural, thermal, and dynamic analyses of mechanical systems, and also visualization of the results. Full-color graphics are used throughout the text. |
trusses problems with solutions: Evolutionary Computation in Combinatorial Optimization Leslie Pérez Cáceres, Sébastien Verel, 2022-04-03 This book constitutes the refereed proceedings of the 22nd European Conference on Evolutionary Computation in Combinatorial Optimization, EvoCOP 2022, held as part of Evo*2022, in Madrid, Spain, during April 20-21, 2022, co-located with the Evo*2022 events: EvoMUSART, EvoApplications, and EuroGP. The 13 revised full papers presented in this book were carefully reviewed and selected from 28 submissions. They present recent theoretical and experimental advances in combinatorial optimization, evolutionary algorithms, and related research fields. |
trusses problems with solutions: Multiobjective Problem Solving from Nature Joshua Knowles, David Corne, Kalyanmoy Deb, 2008-01-28 This text examines how multiobjective evolutionary algorithms and related techniques can be used to solve problems, particularly in the disciplines of science and engineering. Contributions by leading researchers show how the concept of multiobjective optimization can be used to reformulate and resolve problems in areas such as constrained optimization, co-evolution, classification, inverse modeling, and design. |
trusses problems with solutions: Examples in Structural Analysis, Second Edition William M.C. McKenzie, 2013-12-20 This second edition of Examples in Structural Analysis uses a step-by-step approach and provides an extensive collection of fully worked and graded examples for a wide variety of structural analysis problems. It presents detailed information on the methods of solutions to problems and the results obtained. Also given within the text is a summary of each of the principal analysis techniques inherent in the design process and where appropriate, an explanation of the mathematical models used. The text emphasises that software should only be used if designers have the appropriate knowledge and understanding of the mathematical modelling, assumptions and limitations inherent in the programs they use. It establishes the use of hand-methods for obtaining approximate solutions during preliminary design and an independent check on the answers obtained from computer analyses. What’s New in the Second Edition: New chapters cover the development and use of influence lines for determinate and indeterminate beams, as well as the use of approximate analyses for indeterminate pin-jointed and rigid-jointed plane-frames. This edition includes a rewrite of the chapter on buckling instability, expands on beams and on the use of the unit load method applied to singly redundant frames. The x-y-z co-ordinate system and symbols have been modified to reflect the conventions adopted in the structural Eurocodes. William M. C. McKenzie is also the author of six design textbooks relating to the British Standards and the Eurocodes for structural design and one structural analysis textbook. As a member of the Institute of Physics, he is both a chartered engineer and a chartered physicist and has been involved in consultancy, research and teaching for more than 35 years. |
trusses problems with solutions: Advances and Trends in Structural Engineering, Mechanics and Computation Alphose Zingoni, 2010-08-16 Advances and Trends in Structural Engineering, Mechanics and Computation features over 300 papers classified into 21 sections, which were presented at the Fourth International Conference on Structural Engineering, Mechanics and Computation (SEMC 2010, Cape Town, South Africa, 6-8 September 2010). The SEMC conferences have been held every 3 years in |
trusses problems with solutions: Engineering Finite Element Analysis Ramana Pidaparti, 2022-06-01 Finite element analysis is a basic foundational topic that all engineering majors need to understand in order for them to be productive engineering analysts for a variety of industries. This book provides an introductory treatment of finite element analysis with an overview of the various fundamental concepts and applications. It introduces the basic concepts of the finite element method and examples of analysis using systematic methodologies based on ANSYS software. Finite element concepts involving one-dimensional problems are discussed in detail so the reader can thoroughly comprehend the concepts and progressively build upon those problems to aid in analyzing two-dimensional and three-dimensional problems. Moreover, the analysis processes are listed step-by-step for easy implementation, and an overview of two-dimensional and three-dimensional concepts and problems is also provided. In addition, multiphysics problems involving coupled analysis examples are presented to further illustrate the broad applicability of the finite element method for a variety of engineering disciplines. The book is primarily targeted toward undergraduate students majoring in civil, biomedical, mechanical, electrical, and aerospace engineering and any other fields involving aspects of engineering analysis. |
trusses problems with solutions: Scientific and Technical Aerospace Reports , 1994 |
trusses problems with solutions: Structural Analysis O. A. Bauchau, J.I. Craig, 2009-08-03 The authors and their colleagues developed this text over many years, teaching undergraduate and graduate courses in structural analysis courses at the Daniel Guggenheim School of Aerospace Engineering of the Georgia Institute of Technology. The emphasis is on clarity and unity in the presentation of basic structural analysis concepts and methods. The equations of linear elasticity and basic constitutive behaviour of isotropic and composite materials are reviewed. The text focuses on the analysis of practical structural components including bars, beams and plates. Particular attention is devoted to the analysis of thin-walled beams under bending shearing and torsion. Advanced topics such as warping, non-uniform torsion, shear deformations, thermal effect and plastic deformations are addressed. A unified treatment of work and energy principles is provided that naturally leads to an examination of approximate analysis methods including an introduction to matrix and finite element methods. This teaching tool based on practical situations and thorough methodology should prove valuable to both lecturers and students of structural analysis in engineering worldwide. This is a textbook for teaching structural analysis of aerospace structures. It can be used for 3rd and 4th year students in aerospace engineering, as well as for 1st and 2nd year graduate students in aerospace and mechanical engineering. |
trusses problems with solutions: Advances in Swarm Intelligence Anupam Biswas, Can B. Kalayci, Seyedali Mirjalili, 2022-10-01 Swarm Intelligence (SI) has grown significantly, both from the perspective of algorithmic development and applications covering almost all disciplines science and technology. This book emphasizes the studies of existing SI techniques, their variants and applications. The book also contains reviews of new developments in SI techniques and hybridizations. Algorithm specific studies covering basic introduction and analysis of key components of these algorithms, such as convergence, balance of solution accuracy, computational costs, tuning and control of parameters. Application specific studies incorporating the ways of designing objective functions, solution representation and constraint handling. The book also includes studies on application domain specific adaptations in the SI techniques. The book will be beneficial for academicians and researchers from various disciplines of engineering and science working in applications of SI and other optimization problems. |
trusses problems with solutions: Criteria and Methods of Structural Optimization Andrzej M Brandt, 1987-06-30 This book is intended to serve all those who are interested in structural opti mization, whether they work in this field or study it for other purposes. Rapid growth of interest in the cognitive aspects of optimization and the increas ing demands that the present day engineer has to meet in modern design have created the need of a monographic treatment of the subject. The vast number and wide range of structural optimization problems formulated and investigated in the last twenty years call for an attempt to sum up the pres ent state of knowledge in this domain and to outline the directions of its further development. The present authors undertook this task, hoping that the result would stimulate further work towards finding new methods and solutions and increasing the range of applications of the optimization methods to structural design. The immediate aim of the book is to present the basic criteria and methods of optimization and to provide a reference guide to the most important publications in the field. 'The book consists of fourteen chapters. Chapter 1 introduces the basic concepts, definitions and assumptions relating to structural optimization. Chapter 2 gives the foundations of optimization for minimum elastic strain potential or maximum rigidity, and sets a basis for optimization of bar, plate and lattice structures. Chapter 3 presents criteria of strength design and their applications to plane structures. |
trusses problems with solutions: Biomechanics Ghias Kharmanda, Abdelkhalak El Hami, 2017-01-03 In this book, the authors present in detail several recent methodologies and algorithms that they developed during the last fifteen years. The deterministic methods account for uncertainties through empirical safety factors, which implies that the actual uncertainties in materials, geometry and loading are not truly considered. This problem becomes much more complicated when considering biomechanical applications where a number of uncertainties are encountered in the design of prosthesis systems. This book implements improved numerical strategies and algorithms that can be applied to biomechanical studies. |
trusses problems with solutions: The Michigan technic , 1895 |
trusses problems with solutions: Proceedings of the Estonian Academy of Sciences, Physics and Mathematics , 1999-09 |
trusses problems with solutions: Design of Building Trusses James Ambrose, 1994-09-28 A practical, up-to-date introduction on truss analysis, application and design. Describes the influence of trusses on design development as well as the means for design and detailing of truss construction utilizing contemporary building technologies. Illustrations include both historical and recent uses of trusses. |
trusses problems with solutions: Recent Advances in Swarm Intelligence and Evolutionary Computation Xin-She Yang, 2014-12-27 This timely review volume summarizes the state-of-the-art developments in nature-inspired algorithms and applications with the emphasis on swarm intelligence and bio-inspired computation. Topics include the analysis and overview of swarm intelligence and evolutionary computation, hybrid metaheuristic algorithms, bat algorithm, discrete cuckoo search, firefly algorithm, particle swarm optimization, and harmony search as well as convergent hybridization. Application case studies have focused on the dehydration of fruits and vegetables by the firefly algorithm and goal programming, feature selection by the binary flower pollination algorithm, job shop scheduling, single row facility layout optimization, training of feed-forward neural networks, damage and stiffness identification, synthesis of cross-ambiguity functions by the bat algorithm, web document clustering, truss analysis, water distribution networks, sustainable building designs and others. As a timely review, this book can serve as an ideal reference for graduates, lecturers, engineers and researchers in computer science, evolutionary computing, artificial intelligence, machine learning, computational intelligence, data mining, engineering optimization and designs. |
trusses problems with solutions: Creating and Leading High-Performance Organizations Cecil V. “Buddy” Martinette Jr., Creating and Leading High-Performance Organizations by Buddy Martinette is a compelling book that guides leaders in building and leading organizations that excel in performance. With his transformative leadership approach, Martinette shares his firsthand experience of transforming the culture of the Wilmington Fire Department, shifting it from a rule-driven and authoritarian organization to one driven by core values, empowerment, and trust. Throughout the book, readers will discover the building blocks necessary to cultivate a high-performance leadership culture within their own organizations. Martinette emphasizes the crucial interplay between personal and organizational aspects of leadership, illustrating how they work together to create an environment conducive to high performance. The concepts presented in the book are applicable to leaders at all levels, recognizing that effective leadership extends beyond the chief or CEO. By providing a framework that aligns goals and actions, Creating and Leading High-Performance Organizations enables leaders to drive their organizations toward exceptional performance. Readers will gain practical strategies, rooted in real-life experiences, that support the development of a high-performance organizational culture. Testimonials “Chief Martinette’s leadership transformed the culture of the Wilmington (NC) Fire Department from a rule-driven, very authoritarian organization to one based on core values, empowerment, and trust. That cultural change is his legacy.” —Wilmington (NC) Fire Chief Jon S. Mason |
trusses problems with solutions: Brannigan's Building Construction for the Fire Service Francis Brannigan, Glenn Corbett, 2010-02-22 Brannigan’s Building Construction for the Fire Service, Fourth Edition is a must read for fire fighters, prospective fire fighters, and fire science students. This edition continues the Brannigan tradition of using plain language to describe technical information about different building types and their unique hazards. This text ensures that critical fire fighting information is easy-to-understand and gives valuable experience to fire fighters before stepping onto the fireground. The first edition of Building Construction for the Fire Service was published in 1971. Frank Brannigan was compelled to write the most comprehensive building construction text for the fire service so that he could save fire fighters’ lives. His passion for detail and extensive practical experience helped him to develop the most popular text on the market. His motto of: “Know your buildings,” informs every aspect of this new edition of the text. Listen to a Podcast with Brannigan's Building Construction for the Fire Service, Fourth Edition co-author Glenn Corbett to learn more about this training program! Glenn discusses his relationship with the late Frank Brannigan, the dangers of heavy construction timber, occupancy specific hazards, and other areas of emphasis within the Fourth Edition. To listen now, visit: http://d2jw81rkebrcvk.cloudfront.net/assets.multimedia/audio/Building_Construction.mp3. |
trusses problems with solutions: Applied Mechanics Reviews , 1967 |
Engineering Mechanics - IIT Bombay
Analysis of Trusses by the Method of Joints • Dismember the truss and create a freebody diagram for each member and pin. • The two forces exerted on each member are equal, have the same …
Engineering Mechanics: Problems and Solutions
This is followed up by an analysis of trusses; the concepts of centroid and center of gravity, moment of inertia, bending moment etc. Moving beyond the mechanics of static bodies, the …
Chapter 6: Analysis of Structures - Purdue University
6.2 -6.3 Trusses Trusses are used commonly in Steel buildings and bridges. All straight members connected together with pin joints connected only at the ends of the members and all external …
Finite Element Truss - University of New Mexico
We limited the discussion to statically determinate structures and solved for the forces in elements and reactions at supports using basic concepts from statics. In this section, we will apply basic …
Trusses - Germanna
Solving for Reaction Forces. Consider the truss in the figure below, it will be used for all explanations throughout the handout. First, start by examining the forces on the entire …
Annex 1: Truss Analysis. The Method of Joints
In this section it will be analyzed a simple Warren truss created with five equilateral triangles, using the Method of Joints (5). The analysis for isosceles triangles will be similar. The analysis …
Analysis of Truss Structures - UMD
Solution Strategy. Compute member forces at points B and G. Use symmetry ! member forces on right-hand side of structure. Verify equilibrium at point F. Method of Sections. Procedure and …
Simple Truss Problems Linear Algebraic Systems - Syracuse …
Simple Trusses The simplest configuration for a stable truss is a triangle as shown in red above.
TRUSSES - MIT - Massachusetts Institute of Technology
TRUSSES. David Roylance Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge, MA 02139 June 8, 2000. Introduction.
ME 101: Engineering Mechanics - IIT Guwahati
Determine the reactions at A by solving the equations for the sum of all horizontal force components and all vertical force components. Check the values obtained for the reactions by …
4.2 Analysis of Trusses - uomus.edu.iq
Truss analysis using the method of joints is greatly simplified if we can first identify those members which support no loading. These zero-force members are used to increase the …
CE 371- Structural Analysis I Homework #3 Solutions - Purdue …
Classify each structure shown below a stable or unstable. If stable, determine whether they are statically determinate or statically indeterminate. Explain your reasoning. If statically …
Analysis of Statically Determinate Trusses - Anasayfa
A truss is one of the major types of engineering structures which provides a practical and economical solution for many engineering constructions, especially in the design of bridges …
Method of Joints - University of Memphis
In the method of joints, we are going to assume the condition of each of the members, ¢ draw a free body diagram of the connection points, and. ¢ apply two of our three equilibrium …
Solution of Beams and Trusses Problems - UPC Universitat …
Solution of Beams and Trusses Problems. If our structure is made of multiple elements that can be characterized as beams or trusses, the best approach to the problem is with these …
Structural Analysis: Space Truss - IIT Guwahati
Free Body Diagrams: Forces of Interactions. force components must be consistently represented in opposite directions on the separate FBDs (Ex: Pin at A). apply action-and-reaction principle …
160.8.2 Virtual Work Truss Example joint loads - San José …
Example Using the Principle of Virtual Work. Consider the idealized truss structure with a pin support at A and a roller support at C. The truss is subjected to applied loads at D and E.
Method of Sections for Truss Analysis - Texas A&M University …
Method of Sections (relies on internal forces being in equilibrium with external forces on a section) Determine support reaction forces. Cut a section in such a way that force action lines intersect. …
Trusses Problems With Solutions (PDF) - netsec.csuci.edu
professional dealing with structural defects, truss problems can be significant headaches. This comprehensive guide dives deep into common truss issues, explaining their causes, and …
*6.5 Space Trusses - mecanica-ufrj.educacao.ws
*6.5 Space Trusses A space truss consists of members joined together at their ends to form a stable three-dimensional structure. The simplest form of a space truss is a ... PROBLEMS All …
CHAPTER 5 Indeterminate Structures: The Truss
problems. We see that we must contend with three requirements: Static Equilibrium, Compatibility of Deformation, and Constitutive Relations. A less fancy phrasing for the latter is Force …
Steven Vukazich San Jose State University
Simple Trusses using the Method of Sections. A B C 6 ft 6 ft 8 ft 3 k 4 k D E Analysis Example Using the Method of Sections Consider the idealized truss structure with a pin support at E …
MALLA REDDY COLLEGE OF ENGINEERING
Analysis of Trusses: Stiffness Matrix for Plane truss element, Stress Calculations and Problems. Finite element modeling of two dimensional stress analysis with constant strain triangles and …
FEM Program for Space Trusses - Quickfem
are not restricted to space trusses, and may in fact be used for more general problems. The stiffness modifier is invoked by Kmod = ModifiedMasterStiffness[nodtag, K] (21.4) The …
7 Space Trusses - Springer
Space Trusses 225 (7.14) where J; through 8 6 are the nodal displacements in reference to the global system and c, = cos xX, C2 = cos xY and C3 = cos xZ are the direction cosines ofthe …
An exact solution of truss vibration problems - Semantic Scholar
The Elements by a System of Transfer equations (EST) method offers exact solutions to various vibration problems of trusses, beams, and frames. The method can be regarded as an …
Statically Determinate Structures - UMD
Introduction Statical Determinacy of Trusses Statical Determinacy of Planar Structures Indeterminacy of Beams Indeterminacy of Frames Stability. Determinacy of Trusses. Test …
Stiffness Methods for Systematic Analysis of Structures
For space (3D) trusses, all the same concepts of 2D truss analysis still hold. • 3 dofs per node • Transformation matrix becomes 3x3 The main differences are: ... The overall methodology of …
A truss is a structure that consists of All external forces (loads ...
Simple Trusses: The basic building block of a truss is a triangle. Large truss are constructed by attaching ... Solved Problems on Truss Problem: Using the method of joints, indicate all the …
Analysis of Structures - Baylor University
Trusses are constructed using triangles and are also classified by the basic design used. The Warren truss is perhaps the most common truss for both simple and continuous trusses. For …
Statics FE review 032712 - University of Utah
Trusses The truss model requires that all members be two-force members. This further requires the assumptions that: ... are applied at connection points. As a result, the forces in prismatic …
Force Method for Analysis of Indeterminate Structures
Influence lines for Determinate structures (Ref: Chapter 6) Influence line is a diagram that shows the variation for a particular force/moment at specific location in a structure as a unit load …
Analysis of Statically Determinate Trusses - UMD
13 SOLUTION Externally stable, since the reactions are not concurrent or parallel.Since b = 19, r = 3, j = 11, then b + r = 2j or 22 = 22. Therefore, the truss is statically determinate. By …
ENGINEERING MECHANICS (R20A0303) - MRCET
compute their resultant and solve problems using equations of equilibrium. UNIT - 2 CO2: Perform analysis of bodies lying on rough surfaces. UNIT - 3 CO3: Explain the concept of analysis of …
ME 101: Engineering Mechanics - IIT Guwahati
ME101: Text/Reference Books I. H. Shames , Engineering Mechanics: Statics and dynamics , 4 th Ed, PHI, 2002. F. P. Beer and E. R. Johnston , Vector Mechanics for ...
MAE 4700/5700 (Spring 2014) Solutions: Homework 1 Plane …
MAE 4700/5700 (Spring 2014) Solutions: Homework 1 Plane trusses Finite Element Analysis for Mechanical & Aerospace Design Page 1 of 12 Problem 1 - Analysis of a three bar structure …
FRAMES AND MACHINES - Purdue University
FRAMES AND MACHINES Learning Objectives 1). To evaluate the unknown reactions at the supports and the interaction forces at the connection points of a rigid frame in equilibrium by …
3D Truss Analysis - Duke University
2 CEE 421L. Matrix Structural Analysis – Duke University – Fall 2014 – H.P. Gavin 2 Coordinate Transformation Global and local coordinates. L= q (x2 −x 1)2 + (y 2 −y 1)2 + (z 2 −z 1)2 cosθ x=
Trusses Nonlinear Problems Solution with Numerical …
Trusses Nonlinear Problems Solution with Numerical Methods of Cubic Convergence Order L.A.F. SOUZA1*, E.V. CASTELANI2, W.V.I. SHIRABAYASHI2, A. ALIANO FILHO3 and R.D. …
Structural Stability and Determinacy - uap-bd.edu
6 Problems on AFD, SFD, BMD of Frames 1. Draw the AFD, SFD and BMD of the beam bcd in the frame abcde loaded as shown below. 1 k/ft 2. Determine the degree of statical …
Virtual Work 0910 - colincaprani.com
Structural Analysis III 4 Dr. C. Caprani 1. Introduction 1.1 General Virtual Work is a fundamental theory in the mechanics of bodies. So fundamental in fact, that Newton’s 3 equations of …
Statically Determinate Structures - UMD
Introduction Statical Determinacy of Trusses Statical Determinacy of Planar Structures Indeterminacy of Beams Indeterminacy of Frames Stability. Equations in Two Dimensions. …
Example 2 - University of Nebraska–Lincoln
2m B 2m C 7 4 4 o C 2,24 r G' 2.24 us 2' 4v3 k If the 2-kN force acting on the truss of Prob. were removed, Identify by inspection those members
Design Guide For Timber Trusses Cover - Carolina …
Necessarily, ideal trusses form the conceptual starting point. The real trusses considered in this guide are more general in that they violate one or more of the ideal-truss assumptions to make …
CHAPTER 6 Applications of Castigliano’s Theorems
Coplanar trusses In figure 6.2(b) truss displacements of joint i are and for joint j are . At joint i the truss and axial displacements are related by and as shown in figure 6.3. Likewise at joint j …
Model Answer Q1, 2013: Institution of Structural Engineers …
Both schemes are braced steel framed solutions. In both solutions, steel trusses are proposed for the factory area to meet the need for a column free floor area. The storage facility is also a …
Statics and Introduction to Mechanics of Materials - Ohio …
Develop a systematic approach to solving problems, including careful sketching, precise mathematical notation, clear presentation of solutions, and computer generated plotting of …
Steven Vukazich San Jose State University
160.8.1 Virtual Work for Trusses Joint loads Author: Steve Vukazich Created Date: 8/7/2018 5:40:46 PM ...
CSUSB ScholarWorks - California State University, San …
Testing Trusses Andrew J. Hughes California State University, San Bernardino, andrew.hughes@csusb.edu ... Refine design solutions to address criteria and constraints. o …
Geometric optimization of steel trusses with parallel chords
The application of optimization to the solution of practical structural engineering problems has been very limited, despite the great development of the techniques. One of the main reasons …
Truss Analysis Discussion and Interpretation Using Linear …
and critical trusses. In Section 5 we discuss the compatibility of systems of lin-ear inequalities and the mathematical structure of their solutions. In Section 6 we revisit the truss analysis problem …
Finite Element Course ANSYS Mechanical Tutorial Tutorial 1 …
problems in structural mechanics, heat transfer, fluid mechanics and electro-magnetics. We next select the appropriate element type for our problem from this large list. Consider this as …
Analysis of Statically Determinate Structures - UMD
39 Example 2-9 The side girder shown in the photo supports the boat and deck. An idealized model of this girder is shown in the figure below, where it can be assumed A is a roller and B …
Chapter 3 Finite Element Method for Trusses - Springer
82 3 Finite Element Method for Trusses ℓ(e) x(e) 1 x(e) 2 x x1 x2 x3 u(e) 1 u(e) 2 p(e) 0 u(x) global node i local node 1 global node j local node 2 Fig. 3.1 Truss finite element with two degrees of …
Truss Problems And Solutions - resources.caih.jhu.edu
Truss Problems And Solutions Arturo Cuomo Simple Truss Problems Linear Algebraic Systems - Syracuse … The simplest configuration for a stable truss is a ... What are the most common …
STRESSES IN BEAMS - MIT
thex-derivativeofthebeam’sverticaldeflectionfunctionv(x)1: u=−yv;x (1) wherethecommaindicatesdi erentiationwithrespecttotheindicatedvariable(v;x
BAR & TRUSS FINITE ELEMENT Direct Stiffness Method
–Direct method: Easy to understand, limited to 1D problems –Variational method –Weighted residual method • Objectives –Determine displacements, forces, and supporting reactions …
UNIT 1 SIMPLE STRESSES AND STRAINS Strains Simple …
In many cases, known as determinate problems, the analysis of forces within a solid can be calculated treating it as rigid. 1.2.2 Stresses and Strains When we apply forces on solids, …
Strength of Materials (Problems and Solutions) - unideb.hu
2 Editor: Tamás Mankovits PhD Dávid Huri Authors: Tamás Mankovits PhD Dávid Huri Manuscript closed: 18/04/2018 ISBN 978-963-490-030-6 Published by the University of Debrecen
Chapter 6: Indeterminate Structures – Direct Stiffness Method
problems can be solved in the same way. The most important characteristic is the ability to automate the solution process so that implementation in a computer program is possible. Its …
FEM Programs for Plane Trusses and Frames - Quickfem
Chapter22: FEMPROGRAMS FORPLANETRUSSES ANDFRAMES 22–6 pdof A list of the prescribed degrees of freedom identified by their global number. For the example truss of …
Truss Analysis –Method of Joints - San José State University
1. Draw a Free Body Diagram (FBD) of the entire truss cut loose from its supports and find the support reactions using the equations of equilibrium (we will see that for some truss structures …
Chapter 3
If (i) is degree of determination of trusses, so: i = (m + r) – 2j Virtual Work Method or Unit Load Method are used for solving the analysis of plane trusses indeterminate whether it is external …
Castigliano's Theorem Solved Problems - Montogue Quiz
X Problems – Castigliano’s theorem. Problem 10 (Philpot, 2013, w/ permission) Employing Castigliano’s second theorem, calculate the slope of the beam at A for the loading shown in …
1. Solve Problem 1.3-3(c) - University of Florida
It is desired to use FEM to solve the two plane truss problems shown in the figure below. Assume AE = 106 N, L = 1 m. Before solving the global ... 1 1 3 3 2 1 2 3. Solution: After deleting rows …
CE -474: Structural Analysis II - Purdue University
Concepts of Traction and Stress In general, Traction is the distributed force per unit area acting at a point on any (external) surface of a body or a part of a body. Traction is a vector represented …
3.11 Solutions Problem Set # 6
3.11 Solutions Problem Set # 6 Problem #1 Determine the maximum shear stress and rate of twist of the given shaft if a 10 kNm torque is applied to it. If the length of the shaft is 15 m, how much …
Geometrical aspects of optimum truss like structures for …
(2010). Partial solutions of discrete optimum trusses for three-point problems can be found in Prager (1978a, b) although the assumptions made in the papers limit the design to only those …
UNIT 2 INFLUENCE LINES FOR STATICALLY …
I SAQ I la) How 1s a panrlleti hcant d~fierent from a 5implc bearn '" I (b) Resolve Exaniple 2.1 by a.;sumiog the le!igth of each pnncl tcr Sr ' !?I 2.3 INFLUENCE LINES FOR STATICALLY …