腰椎力学分析的数值模拟与实验研究

采用数值模拟和实验测试技术对两种不同内固定法的腰椎模型进行应力和变形分析，基于CT图像建立L4-S1的三维数值模型，经ANSYS计算分析得出五种工况下的终板应力值；在实验中采用了一种薄膜压力测试传感器结合图像处理的方法，提高测试椎间盘压力分布的精度；同时采用数字图像相关技术对腰椎骨上下关节突在承载情况下的空间位移进行了测量，获得了腰椎间盘（L3-L4）在承受轴压、前屈后伸和侧弯情况下的压力分布，以及对应的关节突的位移迹线。结果表明：本研究采用的数值分析技术和实验开发的测试技术可操作性强，精度满足要求，有望在类似的生物力学分析中得到应用。

Numerical Simulation and Experimental Study on the Lumbar Vertebrae Mechanics

Stress and deformation analysis of vertebrae segment was carried out based on numerical simulation and experimental test technologies. 3D numerical model L4-S1 was reconstructed by CT-images. Stress distribution at the intervertebral disc (L3-L4) was obtained when the lumbar was subjected to flexion/extension, lateral bending, and axial twist rotations based on ANSYS code. In experiment, a thin pressure film was used to measure bearing stress at the intervertebral disc. Digital image processing techniques was applied to improve the sensitivity of measurement. Moreover, the digital image correlation technique was also applied to identify the movement of facet joints. Results show that the numerical and experimental methods proposed in this paper are rational and easy to apply to biomedical studies of lumbar mechanics.