Additively manufactured polymer parts are often designed like composite sandwich structures. In this work, sandwich beam-like specimens with hexagonal, triangular and rectangular infills were manufactured with different infill densities. An influence of the shape of the infill on the overall stiffness was observed. The bending stiffness of the hexagonal specimens was between 13% and 25% lower than that of the other two cases that instead showed similar performances. Numerical simulations were performed using both shell and solid elements for the infill, to check if it was possible to model the differences observed experimentally. All simulations lead to accurate bending stiffness predictions, except for the rectangular infills with higher infill densities, for which overprediction between 20% and 25% was obtained. Based on these results, strategies for the finite element analysis of additively manufactured composite structures are discussed.

增材制造的聚合物零件通常设计成类似于复合夹心结构。在这项工作中，制造了具有不同填充密度的六边形，三角形和矩形填充物的夹心梁状样品。观察到填充物的形状对整体刚度的影响。六角形试样的弯曲刚度比其他两个表现出相似性能的情况低了13％至25％。使用填充的壳和固体元素进行了数值模拟，以检查是否可以对实验中观察到的差异进行建模。除具有较高填充密度的矩形填充物外，所有模拟均能得出准确的弯曲刚度预测值，而矩形填充物具有20％至25％的过高预测值。根据这些结果，