CE 5310 Lecture Notes - Lecture 1: Moment Distribution Method, Elastic Modulus, Buckling
Document Summary
Fundamental differences between elastic design (ed) and plastic design (pd) The most common method around the world for structural design has been the elastic design method, in which elastic structural analysis is carried out to determine the internal force magnitude and its distribution. Design is then performed based on those elastic force demands. If inelastic response is expected, appropriate detailing provisions are followed to meet the expected ductility demands. However, when a structure goes beyond elastic response, the yielded members generally cannot sustain additional force due to degraded stiffness, thus leading to significant force redistribution in the entire structure. Therefore, when struck by a major ground motion, a structure designed based on elastic force distribution can undergo severe inelastic deformations in a rather uncontrolled manner (unknown yield mechanism). The inelastic activity can be unevenly and widely distributed in the structure, resulting in undesirable response and making repair work after earthquake much more difficult and costly (goel and leelataviwat, 1998).
