Calculation Method for Ultimate Bearing Capacity of Structure and Its Convergence

In order to improve the accuracy and efficiency while considering bi-nonlinear computation of ultimate bearing capacity of structures,the arc length increment method and displacement increment method were investigated respectively by analyzing the increment parameters and the convergent process of unbalanced force.The results were studied and compared between the two methods.A new displacement increment method accounting for all degrees of freedom was proposed.The ultimate bearing capacities of different structures were compared with different increment methods,through which the precision,efficiency and applicable range were investigated.The results show that both arc length increment method and displacement increment method are efficient in bi-nonlinear analysis of structures,and the applicability of displacement increment method is better.The conclusion offers a good reference in the determination of reasonable calculating method for bi-nonlinear analysis of structures.