Effect of pore defects on compressive properties of 3D printed dot matrix structures

Most of the new ship protection structure preparation processes use 3D printing technology. to study the influence of internal pore defects on the overall structural mechanical properties of SLM additively manufactured metal dot structures, the compression behavior and mechanical response of 316L stainless steel lattice structures with internal defects prepared by selective laser melting (SLM) was investigated using Gurson-Tvergaard-Needleman (GTN) porous metal plastic model with internal voids in consideration. The damage parameters of GTN model were optimized with the combination of simulation and experiment using the Central Composite Design (CCD)-Response Surface Method(RSM). The results show that the calibrated GTN model for 316L steel can more accurately predict the failure mechanical behavior, The numerical values of the damage evolution of the point structure with initial internal defects under quasi-static compression are in relatively good agreement with the experimental results. The related research results provide a reference for evaluating the mechanical properties of new ship protection structures fabricated by SLM additive manufacturing.