新型空心球结构的压缩力学性能

Compressive mechanical properties of new type of hollow sphere structure

提出新型空心球结构,该结构是将球体上穿孔的空心球按照体心立方体进行排列和连接.通过实验研究了3D打印的单胞和胞元组合结构的压缩力学性能,建立单胞结构的三维有限元数值模型,实验结果验证了有限元模型的有效性.通过数值模拟研究穿孔空心球壁厚和孔径对结构弹性模量以及初始屈服应力的影响.结果表明,单胞结构的变形行为包括弹性变形、坍塌变形以及结构的自接触行为;多胞组合结构的变形过程包括弹性阶段、大变形阶段以及致密化阶段,其中大变形是由结构的层层连续坍塌变形所导致的;结构的弹性模量和初始屈服应力随壁厚的增大而增大,随孔径的增大而减小;与壁厚变化相比,结构的力学性能对孔径变化更为敏感.

A new hollow sphere structure was proposed.Hollow spheres perforated with several holes were bonded in a body-centered cubic(BCC)pattern in this new structure.The compressive mechanical properties of unit and multi-unit BCC packing perforated hollow sphere structures(PHSS)fabricated through three-dimension(3D)printing technology were investigated by experiments,and the unit structure corresponding to the experiment was modelled by using the 3D finite element method(FEM).The validity of the FE model was confirmed by experimental results.The effect of wall thickness and hole diameter of perforated hollow sphere on elastic modulus and initial yield stress of the structure was evaluated by FEM.The results showed that the compression deformation behaviors of the unit structure included elastic deformation,collapse deformation and structural self-contact behavior;the multi-unit structure experienced elastic,large deformation and densification stages,among which the large deformation behavior was caused by the layer by layer collapsing in the structure;the Young’s modulus and initial yield stress both increased with the sphere wall thickness and decreased with the sphere hole diameter;the mechanical properties were more sensitive to the change of hole diameter than wall thickness.