SEMIANALYTICAL STATIC NONLINEAR STRUCTURAL SENSITIVITY ANALYSIS

The paper discusses two uses of the semi-analytical method for nonline ar sensitivity analysis. First, the application to noncritical respons e is analyzed. It is shown that the semi-analytical method is equivale nt to a particular form of the overall finite difference approach. It is concluded that the difference between overall finite differences an d the semi-analytical approach is blurred for the case of nonlinear st atic response. Next, the application of the semi-analytical method to calculating sensitivities of limit loads is discussed. A formulation t hat is easy to implement in general purpose finite element programs is derived. Three examples are used to demonstrate the application of th e formulation and to explore its accuracy.