FE Civil Exam Prep 38, Beam Bending — Flexure Formula and Section Modulus

This podcast is made by Ran Chen, who holds an EA license, Insurance and Securities licenses (Series 6, 63, 65), and the CFP® designation. He is passionate about opening access to high-quality exam preparation resources and helping learners prepare more effectively for professional certification exams. In this episode you will learn: - The flexure formula, σ = Mc/I, is used to find the maximum bending stress at the outermost fiber of a beam's cross-section. - Section modulus (S = I/c) simplifies the stress calculation to σ = M/S and represents a beam's geometric efficiency in resisting bending. - A critical exam trap is failing to convert the bending moment (M) from kip-feet to kip-inches before calculating stress in kips per square inch (ksi). - For beam design problems, calculate the required section modulus (S_req = M/σ_allow) and then select the lightest W-shape from the NCEES Handbook tables that meets or exceeds this value. - The distance 'c' in the flexure formula is always the distance from the neutral axis to the extreme fiber, which is half the total depth for symmetric cross-sections. For more free exam prep tools, practice questions, and AI-powered explanations, visit https://open-exam-prep.com/ or YouTube Channel: https://www.youtube.com/@Open-exam-prep