基于三维扫描模型的兵马俑足踝有限元分析

FEM simulation on the ankles of Terra-cotta Warriors based on 3D scanning models

利用三维扫描技术获取兵马俑残片的三维点云数据,结合Geomagic Studio和Hypermesh建立高精度的兵马俑足踝残片三维实体网格模型。通过基于ABAQUS的重力作用下的有限元分析,研究足踝部分的Von Mises应力和变形特征,以确定足踝处的受力薄弱部位。为进一步探究模型各残片的最佳点云简化比例,采用点云简化模型进行相同工况的有限元分析,以验证点云简化的可靠性。结果表明:结构在重力作用下可保持安全稳定的状态,相对薄弱部位位于左腿足踝处;对于大部分残片,其最佳简化比例在60%~70%,简化后可有效缩短模型实体化处理时间;采用简化模型得到的有限元结果,其最大Mises应力相比于原始模型的误差小于15%,且应力云图和变形图形状接近,模型简化具有可靠性。

A 3D point cloud dataset of the Terra-cotta Warriors was built by 3D laser scanning,and then a high-precision 3D solid mesh model was established with the assistance of Geomagic Studio and Hypermesh.Using the finite element method(FEM)simulation in the ankles of Terra-cotta Warriors,characteristics of Von Mises stress and deformation were investigated to determine the vulnerable parts of the ankle.The optimal proportion of the points simplified on each fragment was confirmed and applied to FEM simulation with the same condition as the original model,to verify the reliability of simplification.The results show that the whole structure can remain safe and stable under gravity,as the vulnerable part is in the left ankle.For most fragments,the optimal proportion is 60%~70%,which can effectively reduce the modeling time.The error of Von Mises stress in the points-simplified model is less than 15%compared with that of the original model.The stress contour and deformation pattern are also comparable with the original results,which means the process of points simplification can provide comparatively accurate results and save time.