人体腰椎松质骨冲击响应的实验研究

Impact Response of Human Lumbar Vertebral Trabecular Bone

本文利用传统的分离式Ｈｏｐｋｉｎｓｏｎ压杆（ＳＨＰＢ）技术，测试了新鲜人腰椎松质骨在冲击载荷下的力学性质。以表现密度（ρａ）和应变率（ε）为自变量，以弹性模量（Ｅ）、极限强度（σｕ）和终应变（εｕ）为因变量（Ｙ），按模型Ｙ＝ａρｂεｃ拟合出回归方程，并与准静态下相同的模型进行了比较，发现高应变率下弹性模量和极限强度与表观密度的相关性下降，而与应变率的相关上有增高的趋势，终应变与表观密度无关而与应变率的相关性显著提高。本文还对松质骨本构关系进行了探讨。

Biomechanical behaviour of fresh human lumbar vertebral trabecular bone in 3 corpses (all males aged 22-28) was studied under impact loading by using traditional Split Hopkinson Pressure Bar (SHPB)technique. The average strain rate was 483 S-1. Non-linear regression analyses with strength (σu), compressive modulus (E) and ultimate strain (εu) as dependent variables (Y) and strain rate (ε) and apparent density (ρ) as independent variables were performed using the model Y＝aρbεc established by Carter and Hayes. The exponent was 0. 13 between strength and strain rate, and 0. 15 between compressive modulus and strain rate. The variation of ultimate strain was explained best to strain rate (exponent＝1. 65). The variations of strength and compressive modulus were explained well by this model to apparent density, the exponents were 0. 83 and 0. 93 respectively. Ultimate strain varied independently of apparent density. Compared with the same model established at lower strain rate, the exponent between strength or compressive modulus and apparent density is lower, and the exponent between strain rate and strength or moduls tends to be higher at high strain rate.