Damage Mechanism of Reinforced Concrete Shear Walls Under Axial Compressive Force and Contact Explosion

To investigate the dynamic response and damage mechanisms of reinforced concrete (RC) shear walls subjected to the combined action of contact explosions and axial compression, three contact explosion tests were conducted on RC shear walls with a constant axial compression ratio of 0.15 and different charge masses. A self-balancing axial loading device was designed to maintain a continuous and stable axial force during the blast tests. Finite element models were subsequently established using LS-DYNA. The fluid structure interaction (FSI) method was adopted, and the numerical models were validated in terms of crater dimensions and failure modes. Based on the validated model, a numerical parametric study was further conducted to examine the influence of axial compression ratios ranging from 0 to 0.4. The results indicate that the axial compression ratio has a non-monotonic effect on the local damage dimensions of RC shear walls. The wall exhibited a relatively smaller crater area and a more favourable local damage response when the axial compression ratio was approximately 0.2. As the charge mass increased, the failure mode progressively changed from cratering and spalling to perforation and punching shear failure. Based on the experimental and numerical results, empirical relationships were proposed to correlate the crater diameters on the front and rear faces with the charge mass and axial compression ratio. These relationships enable the rapid estimation of local damage dimensions using a limited number of input parameters.