Static and Dynamic Analysis of Nonlinear Structures,

摘要

This report presents the theoretical and computational procedures which have been applied in the design of a general purpose nonlinear computer code for static and dynamic analysis of nonlinear structures. Using the principle of virtual displacements,incremental equations of motion for structures undergoing large displacements and strains are first derived,using the Lagrangian description of deformation. These equations of motion are then discretized using the finite element displacement formulation,and the element characteristics,including 'linear'and 'nonlinear'stiffness matrices,are derived for the particular case of a two dimensional isoparametric finite element. Physical nonlinearity due to material behavior is introduced for elasto-plastic materials,and the constitutive laws for commonly used elasto-plastic models are described.