Large-step explicit time integration via mass matrix tailoring

A method for tailoring mass matrices that allows large time-step explicit transient analysis is presented. It is shown that the accuracy of the present tailored mass matrix preserves the low-frequency contents while effectively replacing the unwanted higher mesh frequencies by a user-desired cutoff frequency. The proposed mass tailoring methods are applicable to elemental, substructural as well as global systems, requiring no modifications of finite element generation routines. It becomes most computationally attractive when used in conjunction with partitioned formulation as the number of higher (or lower) modes to be filtered out (or retained) are significantly reduced. Numerical experiments with the proposed method demonstrate that they are effective in filtering out higher modes in bars, beams, plain stress, and plate bending problems while preserving the dominant low-frequency contents.