The aim of this new experimental work was to understand the effect of loading biaxial combined compression-torsion complexity on the plastic response of three aluminum foams having porosities of 93%, 85% and 78% and nominal relative densities of 7%, 15% and 22%, respectively. An investigation was made of the biaxial plastic response of these open-cell foams, which have a highly uniform architecture with a spherical porosity. These foams were tested under quasi-static complex loading paths using a patented rig, called ACTP. Biaxial combined compression-torsion loading paths were then applied with different torsional component rates. The key responses to be examined were yield stress, stress plateau, energy absorption capacity, and densification strain. It was revealed that the greater the density of the foam, the higher the loading complexity, and the greater the yield strength and the energy absorption capacity. The highest foam strength was thus recorded under the most complicated loading path (i.e., biaxial 60°) for the densest foam (i.e., 78% porosity). However, the foam with a porosity of 93% demonstrated a lower strength under biaxial loading compared to its uniaxial response. This was due to its small cell wall thickness, which was easily damaged. The effect of the loading complexity on the pore closure mechanism of the deformed foams was studied using an image analysis that targeted the axial and the transverse sections. For the 85% and 78% foams, the loading complexities of biaxial-37° and biaxial-45° provided the highest pore closure compared to the other loading complexities. This analysis supported the interpretation of the densification strain results.

这项新的实验工作的目的是了解加载双轴组合压扭复杂性对三种孔隙率分别为93％，85％和78％，标称相对密度为7％，15％和90％的铝泡沫的塑性响应的影响。分别为22％。对这些开孔泡沫的双轴塑性响应进行了研究，这些泡沫具有高度均匀的结构和球形孔隙。这些泡沫使用称为ACTP的专利钻机在准静态复杂载荷路径下进行了测试。然后以不同的扭转分量比率施加双轴组合的压缩扭转载荷路径。要检查的关键响应是屈服应力，应力平稳期，能量吸收能力和致密化应变。结果表明，泡沫的密度越大，加载的复杂性越高，屈服强度和能量吸收能力越大。因此，在最复杂的加载路径（即双轴60°）下，对于最致密的泡沫（即孔隙度为78％）记录了最高的泡沫强度。但是，孔隙率为93％的泡沫塑料在双轴载荷下的强度比其单轴响应低。这是由于其细胞壁厚度小，很容易损坏。使用针对轴向和横向截面的图像分析研究了载荷复杂度对变形泡沫的孔隙封闭机理的影响。对于85％和78％的泡沫，双轴37°和双轴45°的填充复杂性与其他填充复杂性相比提供了最高的孔隙封闭性。该分析支持对致密应变结果的解释。