Strength of Materials

Abstract

When everyday objects and structures experience too much force, they can break or deform beyond recognition. This book explains why this occurs and how engineers can prevent it from happening to their designs. Strength of Materials introduces essential engineering concepts including internal loading, stress, strain, and material properties. Developed for undergraduate courses in mechanics of deformable bodies, the text combines approachable explanations with worked examples, step-by-step problem-solving guides, key takeaways, and concise equation summaries. With a strong focus on both conceptual understanding and practical application, it supports student learning in and beyond the classroom. Freely available and openly licensed, this adaptable resource also serves as a valuable reference for anyone exploring foundational engineering principles. Question bank This book has an accompanying set of practice questions accessible here. These questions are a mix of (1) new questions generated by the author team, and (2) adapted questions from Kurt Gramoll’s Eng Mechanics question bank [accessible via the Apple Store or Google Play]. How to access this book The main landing page for this book is https://doi.org/10.21061/strengthofmaterials. The PDF and EPUB versions are available to download on the left-hand side of the screen. An online, interactive, accessible version of this book is available here. A paperback print version (in color) is available for order here. Are you reviewing or adopting this book for a course? Please help us understand your use by filling out this form. ISBNs ISBN (PDF): 978-1-962841-35-1 ISBN (HTML): 978-1-962841-36-8 ISBN (EPUB): 978-1-962841-34-4 ISBN (print): 978-1-962841-33-7 Table of contents 1. Statics Review 2. Stress 3. Strain 4. Mechanical Properties of Materials 5. Axial Loading 6. Torsion 7. Beams 8. Geometric Properties 9. Bending Loads 10. Shear Loading in Beams 11. Beam Deflection 12. Stress Transformation 13. Thin-Walled Pressure Vessels 14. Combined Loads 15. Columns Appendix A: Geometric Properties of Standard Beams Appendix B: Slope and Deflection Tables Appendix C: Material Properties Appendix D: Units and Order of Magnitude Appendix E: Centroids and Second Moment of Area for Common Shapes Find, adapt, and share resources If you wish to share resources you build from this book or find those shared by other adopters of this book, please join the instructor portal. About the authors James K. Lord James Lord is a Collegiate Professor in the Department of Mechanical Engineering at Virginia Tech, where he has taught foundational mechanics courses since 2014, prior to which he taught a variety of courses at Cal Poly, SLO. Born and raised in England, he holds a master’s degree in mechanical engineering and a PhD in Biomechanical Engineering from Newcastle University. He is active in the American Society for Engineering Education and has won numerous teaching awards. He is passionate about removing barriers to education and has previously contributed to other free mechanics resources, including the popular Engineering Statics: Open and Interactive. After a decade of watching students spend $100+ on a textbook for his course he thought “I could write one of those.” So he did. Amy Richardson Amy Richardson is a research scientist in Engineering Education at Virginia Tech. Before joining Virginia Tech, she spent over 15 years as a community college faculty member, teaching mechanics courses every semester. Amy holds a BS and MS in Civil Engineering, as well as a PhD in Engineering Education. She is passionate about fostering equity in the classroom so that every student has the opportunity to succeed. Contributing to this OER textbook is her way of making foundational engineering mechanics more accessible to all—one small step toward removing barriers in engineering education. Sneha Davison Sneha Davison is an advanced instructor in the Mechanical Engineering Department at Virginia Tech. She also completed her BS (1996), MS (1999), and PhD (2003), all in Engineering Science and Mechanics, from Virginia Tech. She has taught multiple mechanics courses every semester since the fall of 2016. These courses primarily include Statics, Dynamics, Deforms, and Thermodynamics. Beyond teaching in person, she feels that contributing to this OER textbook is the perfect way to reach more students and put the insight she has gained about how to communicate complicated concepts to students to good use. David A. Dillard David A. Dillard is the Adhesive and Sealant Science Professor in the Mechanical Engineering Department at Virginia Tech. He has co-authored over 210 refereed publications and regularly teaches mechanics courses. A recipient of university, national, and international awards, primarily for his research in adhesives, polymers, fracture mechanics, and viscoelasticity, he has been heavily involved in proposing and developing a novel problem-solving platform based on inadequacies he saw in publisher virtual homework feedback for a mechanics of materials course. Having taught this topic for many years, including in-person, virtual, and hybrid formats, he is very interested in seeing an open-source book for this important engineering course. Project support Publication of this work was made possible in part by:

the Open Education Initiative grant, which provides development assistance and financial support to Virginia Tech faculty who wish to use, create, or adapt openly licensed teaching materials to support student learning, VIVA's Open and Affordable Course Content Program, which provided funding and technical support, and Virginia Tech’s Department of Engineering Education, which provided funding and technical assistance

Suggested citation James K. Lord, Amy Richardson, Sneha Davison, and David A. Dillard, Strength of Materials (Virginia Tech Press, 2026). CC BY-NC-SA 4.0. https://doi.org/10.21061/strengthofmaterials. View known errata | Report an error Accessibility Virginia Tech is committed to making its publications accessible in accordance with the Americans with Disabilities Act of 1990. The text, images, and links in the PDF version of this text are tagged structurally and include alternative text, which allows for machine readability. Virginia Tech Press is continuously working to improve accessibility and welcome any feedback from readers. Cover design: Kindred Grey