冲击载荷作用下骨盆三维有限元分析及其生物力学意义

目的:探讨骨盆受到冲击载荷作用的力学行为特征,为临床分析及判断骨盆骨折类型、力学分布、冲击载荷影响提供力学基础。方法:采用计算机仿真模拟方法,将所构建骨盆三维实体模型导入三维有限元分析软件AN-SYS7.0,计算单侧髂前上棘和单侧髂骨正后方部位冲击载荷作用下骨盆的力学行为表现,冲击载荷为0～8000N,峰值8000N,时间自0～40ms,分析主应力值、应力分布情况以及主应力方向上骨盆单元的位移。结果:冲击载荷作用于单侧髂前上棘时,0～10ms主要的应力沿髂后上棘到髂前上棘分布,在冲击后期10ms以后,骶髂关节、髋臼和耻骨支都会产生较大的应力分布;作用于单侧髂骨正后方部位时,0～20ms主要的应力沿髂骨纵行传导,应力分布并没有在冲击峰值10ms时达到最大,而是从20ms之后,应力开始向骶髂关节、双侧耻骨支、坐骨支以及髋臼等部位传导并可见到明显的应力分布。结论:分析冲击载荷作用下骨盆各部位应力分布以及骨盆各个单元在应力作用下的位移变化,有助于临床上进行骨盆损伤内固定力点的选择以及进一步明确骨盆内在应力值分布。

Three-dimensional finite element analysis of pelvis loaded by transient stress and its biomechanical significance

Objective:To explore the mechanical behavior of pelvis loaded by transient stress and provide the mechanical basis for analyzing and judging pelvic fracture classification and mechanical distribution and transient stress affection in clinics.Methods:By means of computer simulation,reading input from reconstructed pelvic three-dimensional model into three-dimensional finite element analysis software ANSYS 7.0,calculated the pelvic mechanical behavior and analyzed the main stress value,stress distribution and pelvic unit displacement in the direction of main stress when unilateral anterior superior iliac spine and unilateral positive backside of ilium was loaded by transient stress,the stress region was 0-8 000 N,peak value was 8 000 N,time range was from 0 ms to 40 ms.Results:When unilateral anterior superior iliac spine loaded by transient stress,0-10 ms,stress distributed from posterior superior iliac spine to anterior superior iliac spine,and on the last 10 ms,there were greater stress distribution around cacroiliac joint,acetabulum and pubic branch.When unilateral positive backside of ilium loaded,between 0 ms and 20 ms,stress transmitted along vertical direction of ilium,and after 20 ms,there were greater stress distribution on cacroiliac joint,both pubic branch,ischium branch and acetabulum.Conclusion:Analyzing the stress distribution of pelvis and units displacement when transient stress was loaded,can provide internal fixation point for treatment of pelvic fracture and further understanding the stress distribution of pelvis.