仿竹子结构八重桁架点阵结构设计与增材制造

Designing and additive manufacturing of bamboo-imitated octet-truss lattice structure

针对航空航天、汽车工程等领域中对轻量化、高强度、高吸能构件的迫切需求,受启发于竹子的特殊宏微观空心结构,提出了空心八重桁架的高比强吸能点阵结构优化设计方法.空心八重桁架点阵结构由空心面心立方体和正八面体点阵结构组合而成,采用光固化技术分别成形3种点阵结构并利用准静态压缩试验测试其力学性能,结果表明:空心八重桁架点阵结构的弹性模量低于空心面心立方体和正八面体点阵结构之和,屈服强度、抗压强度和能量吸收值高于两者之和.当点阵结构的边长为8 mm时,空心八重桁架点阵结构的弹性模量低于空心面心立方体和正八面体点阵结构总和的4.76%,而屈服强度、抗压强度和能量吸收值分别高于空心面心立方体和正八面体点阵结构总和的12.80%,7.09%和51.68%.当空心八重桁架结构的边长从8 mm增加到20 mm时,弹性模量、屈服强度、抗压强度和能量吸收分别下降19.96%,24.73%,30.77%和33.69%.

Aiming at urgently develop lightweight,stronger strength,higher energy absorption structural components,hollow facecentered cubic,octahedron and octet-truss lattice structures were proposed inspired by the special macro and micro hollow characteristics of bamboo. In which,the hollow octet-truss lattice structure was composed with hollow face-centered cube and octahedral lattice structure.The lattice structures were fabricated by stereo lithography appearance technology,and the mechanical properties were obtained by quasi-static compression test.Results reveal that the Young′s modulus of the hollow octet-truss lattice structure is lower the sum of that of the hollow face-centered cubic and the octahedral lattice structure,and its yield strength,compressive strength and energy absorption are higher than the sum of that of two,when the side length of the lattice structure is 8mm,the Young’s modulus of the hollow octet-truss lattice structure is lower than the sum of that of the hollow face-centered cubic and the octahedral lattice structure by 4.76%,while the yield strength,compressive strength and energy absorption are respectively12.80%,7.09% and 51.68% higher than the sum of that of hollow face-centered cubic and octahedral lattice structures.When the side length of the hollow octet-truss structure increases from 8 mm to 20 mm,the Young’s modulus,yield strength,compressive strength and energy absorption of the hollow octet-truss lattice structure decrease by 19.96%,24.73%,30.77%,and 33.69%,respectively.