Numerically generated tangent stiffness matrices using the complex variable derivative method for nonlinear structural analysis

摘要

Accurate tangent stiffness matrices are essential for solving nonlinear structural problems using Newton-like methods. This paper presents a numerical procedure for generating accurate tangent stiffness matri-ces from the derivative approximation of internal force using the complex variable derivative method (CVDM). The present procedure is suitable for problems that require complex constitutive relations and/or kinematic nonlinearities whose models are difficult to linearize, as well as for the incorporation of Newton-like solution strategies with nonlinear structural analyses.