Effective Stiffness in Seismic Design

This lecture covers the computation of inelastic displacement capacity using the plastic hinge method, the analysis of moment-curvature relationship, and the shortcomings of force-based design in seismic engineering. It discusses problems such as the need for initial period estimation, the relationship between local and global ductilities, and the challenges of force-based design based on elastic analysis. The lecture also explores the estimation of effective stiffness of reinforced concrete members and the implications for seismic design. Various examples and analyses are presented to illustrate the issues with force-based design.