Masonry structural damage and failure under blasting vibration

Research on structural dynamic response and damage characteristics under blasting vibration is critical in structural safety assessment and blasting design. An orthotropic dynamic damage constitutive model of structural material is proposed in this article to improve the overly simple dynamic damage models of previous studies. A dynamic increase factor is used to assess the strain rate effect, and the dynamic damage stiffness matrix of the unit body is determined using the Sidoroff energy equivalence principle. The Mazars damage evolution model is used to calculate damage variables in the principal axis directions, and the Hoffman yield failure criterion for orthotropic materials is applied. The orthotropic dynamic damage constitutive model is input into dynamic finite element program LS-DYNA as the user subroutine to simulate the dynamic responses of typical masonry structures according to different blasting vibration excitations. The effects of varying particle peak velocity, principal frequency, and duration of blasting vibration on structural dynamic responses and damage are analyzed. The results show that maximal equivalent stress and strain increase positively with the particle peak velocity, structures have a danger frequency band, and structural damage increases with duration.