Mechanical response and response mechanism of AlSi10Mg porous structures manufactured by laser powder bed fusion: Experimental, theoretical and numerical studies

In order to correctly understand the bearing capacity, failure mode and failure mechanism of AlSi10Mg porous optimized structures at different strain rates under compressive load, a series of experimental and simulative studies were carried out. Through quasi-static and modified Split Hopkinson Pressure Bar (SHPB) experiments, the damage failure modes of the AlSi10Mg porous structures with three different volume fractions are obtained at different strain rates. The stress-strain curves of AlSi10Mg porous structures obtained from the experimental results at different high strain rates show that its mechanical behavior is not sensitive to strain rates. Combined with meso-structure analysis and high-precision numerical simulation, it is found that the shear failure of AlSi10Mg porous structures due to relative dislocation along the inclined section under axial compressive load is the most direct cause of failure, which reveals its failure mechanism. Combining experimental research and theoretical analysis, the energy absorption characteristics and influencing factors of AlSi10Mg porous structures are determined at different strain rates. At the same time, the prediction models of dynamic elastic modulus and dynamic compressive strength of AlSi10Mg porous structures are constructed, which accurately describe the variation law between dynamic elastic modulus, dynamic compressive strength and structural volume fractions. These research works in this paper will provide an important reference for the structure optimal design of lightweight, strong energy absorption and impact resistance.