Evaluation of Numerical Algorithms for the Nonlinear Dynamic Analysis of Large Soil Structure Systems

摘要

The 6.1 Structural Modeling Program at the Naval Civil Engineering Laboratory at Port Hueneme has as a main objective to develop analysis algorithms for the nonlinear analysis of drydocks and other large geotechnical-structural systems. The 6.2 Nonlinear Structural Analysis Program is aimed at implementing those algorithms into a special purpose finite element analysis program that will allow a 3 dimensional nonlinear dynamic analysis of the large structural systems under earthquake and blast type of excitations. This report contins a review and evaluation of these algorithms to assess their applicability towards the 6.2 Program. The issues covered include: reduced modal methods for nonlinear dynamic problems, contact and friction finite element techniques, combination of finite element and recursive boundary element methods, validation of bounding surface plasticity models for saturated cohesive soils and, finally, linear fracture mechanics for concrete. This work is initiated with an exposition of the currently available numerical methods for the solution of the soil-structure interaction problems in the time and frequency domains. Directions are given as to which of the available methods seem to be more applicable for the problem at hand. In particular, complete and substructure methods in the time domain are presented as the most convenient ones. In view of these algorithms the work done under the 6.1 Program is reviewed and evaluated.