TC4钛合金仿生骨植入体单元结构力学性能分析

Mechanical Analysis of Bionic Bone Implant Cell Structure of TC4 Titanium Alloy

为解决钛合金骨仿生骨植入体弹性模量与人骨弹性模量不匹配的问题,采用多孔结构的钛合金骨植入体使其与自体骨的力学性能相适应。根据骨骼部位密度不同力学参数不同的特点,设计了开口杆状单元、开口柱状单元、中心球单元的微孔单元结构,并在不同的结构尺寸下得到11种模型。对这11种模型进行静力学仿真,得到受轴向压缩载荷时骨植入体结构的最大等效应力和应变分布,以及弹性模量数据;采用SLM技术将TC4钛合金粉末加工成试样,做压缩和三点弯曲试验。结果表明,开口杆状单元适用于具有较高的弹性模量抗弯强度的骨骼重建,开口柱状单元适用于弹性模量范围较大的骨骼重建,而中心球单元适合弹性模量较低且变化范围较小的骨骼重建。

In order to solve a series of problems caused by the mismatch between the elastic modulus of titanium alloy bone implant and the elastic modulus of human bone,the porous structure of the titanium alloy bone implant is used to adapt the mechanical properties of the autogenous bone.According to the different density characteristics of different bone parts,three different micro pore cell structures are designed:open rod cell,open column cell and central ball cell.Bionic bone modeling based on these cells,and 11 kinds of membranes were obtained under different structural sizes.The static simulation of 11 models are carried out by using the software ANSYS workbench to obtain the maximum equivalent stress and the maximum equivalent strain distribution of the bone implant structure obtained by the axial compression load,and the elastic modulus data.The TC4 titanium alloy powder is used to manufacture the experimental samples by SLM technology,and the compression and three-point bending tests were performed.Simulation and experimental results show that the open rod-shaped cell is suitable for bone reconstruction with high elastic model and bending strength.The open cylindrical cell is suitable for bone reconstruction with large elastic modulus range,while the central spherical cell is suitable for bone reconstruction with low elastic modulus and small variation range.