Block subspace projection preconditioned conjugate gradient method for structural modal analysis

Abstract

The method for extracting natural vibration frequencies and modes of design models arising when the finite element method is applied to the problems of structural and solid mechanics is proposed. This approach is intended to be used on multicore SMP computers and is an alternative to the conventional block Lanczos and subspace iteration methods widely used in modern FEA software. We present the main idea of the method as well as the parallel fast block incomplete factorization approach for creating efficient preconditioning, the shift technique and other details accelerating the solution and improving the numerical stability. Real-life examples are taken from the computational practice of SCAD Soft IT company and approve the efficiency of the proposed method.