An analysis of the whole process of elastoplastic properties of superstatically fixed beams

Super static fixed beam;  elastoplasticity;  Unit load method;  Plastic hinges;  Concentrated loads

The elastoplastic loading and deformation process of the next superstatic fixed beam under concentrated load is analyzed by the virtual work principle and unit load method. The force deformation can be divided into 4 stages: elastic stage; Plastic deformation stage near the solid branch; Plastic deformation stages occur near the solid branch end and near the concentrated load action point; The solid end is maintained as a plastic hinge, and the plastic zone near the concentrated load action point expands and the plastic zone near the solid support end is unloaded. The bending moment, displacement formula and the relationship between external load and support reaction force at each stage of loading are given, which can be used for engineering structure design.