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    衍生体心立方点阵材料的优化设计及压缩力学行为

    Optimization Design and Compressive Mechanical Behavior of Derivative Body-Centered Cubic Lattice Materials

    • 摘要: 分别在传统体心立方(BCC)点阵结构(H0型)的外围以及外围和中心添加竖直杆,设计出H1型和H2型衍生BCC点阵结构,以AlSi10Mg合金粉末为原料采用激光选区熔化(SLM)技术制备出不同尺寸参数的点阵试样,研究了其压缩力学行为。结果表明:传统和衍生BCC点阵试样的压缩行为均具有线弹性阶段、平台阶段、致密化阶段等3个阶段,属拉伸主导型多孔材料;相同尺寸参数下,H2型BCC点阵试样的比强度、平台应力和单位质量吸能最大,H1型次之,H0型最小。随着单胞高度增加,H1型点阵试样的比强度和单位质量吸能基本不变,平台应力起伏略微增大,能量吸收效率小幅减小;随着单胞宽度增加,H1型点阵试样的比强度、平台应力和单位质量吸能明显降低,能量吸收效率不变;随着斜杆及外围竖直杆杆径增加,H1型点阵试样的比强度、平台应力和单位质量吸能明显增大,能量吸收效率先明显提升后趋于稳定。随着中心竖直杆杆径增加,H2型点阵试样的比强度、平台应力和单位质量吸能增大,能量吸收效率提升。衍生点阵试样的变形模式主要为由下到上的逐层变形,损伤机制为竖直杆的侧向弯曲和斜杆的垂直方向弯曲。

       

      Abstract: By adding vertical rods at periphery and at periphery and center of the traditional body-centered cubic (BCC) lattice structure(H0 type), the H1 and H2 type derivative BCC lattice structures were designed. The lattice samples with different size parameters were prepared by laser selective melting (SLM) with AlSi10Mg alloy powder as raw materials. The compressive mechanical behaviors of samples were studied. The results show that the traditional and derivative BCC lattice samples were all stretching-oriented porous materials, whose compression behaviors could be divided into three stages: linear elastic stage, plateau stage and densification stage. With the same structural parameters, the specific strength, platform stress and energy absorption per unit mass of H2 type BCC lattice sample were the largest, followed by those of H1 type, and those of H0 type were the smallest. With the increase of cell height, the specific strength and energy absorption per unit mass of H1 type lattice samples were basically unchanged, the fluctuation of the platform stress increased slightly, and the energy absorption efficiency decreased slightly. With the increase of cell width, the specific strength, platform stress and energy absorption per unit mass of H1 type lattice samples decreased obviously, and the energy absorption efficiency remained unchanged. With the increase of diameter of inclined and peripheral vertical rod, the specific strength, platform stress and energy absorption per unit mass of H1 type lattice samples increased obviously, and the energy absorption efficiency increased first and then became stable. With the increase of diameter of central vertical bar, the specific strength, platform stress, energy absorption per unit mass and energy absorption efficiency of the H2 type lattice samples increased. The deformation mode of the derivative lattice sample was mainly layer by layer deformation from bottom to top, and the damage mechanism was lateral bending of the vertical rod and vertical bending of the inclined rod.

       

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