Response prediction of geometrically nonlinear structures

The response prediction of geometrically nonlinear elastic structures (GNS) is an important area of research in structural engineering and mechanics. Also, in professional practice it has become mandatory to carry out such an evaluation for long-span and slender structures such as suspension bridges . However, this is often a very difficult task, especially when randomness in loads and material properties have to be taken into account. In this stu dy, the responses of GNS are obtained using the total Lagrangian formulatio n for finite-element discretization. In the presence of uncertainties, the mean and variance of the response of GNS are evaluated by first-order appro ximation and Monte Carlo simulation. Numerical examples are presented to il lustrate the computational process and to study the effects of various para meters such as type of analysis (linear or nonlinear), magnitude of loads a nd load effects, and type of approximation (first order or simulation) on t he main descriptors of the response of GNS. For the cases studied, the resu lts show that first-order approximation and Monte Carlo simulation are in c lose agreement. This indicates that, at least for the numerical examples pr esented, first-order approximation can be used in place of Monte Carlo simu lation. In this manner, computational time is drastically reduced without a significant loss in accuracy.