兔髌韧带压缩力学性能

Compressive Mechanical Properties of Rabbit Patellar Ligaments

目的 研究不同应变率下韧带的压缩应力-应变关系,并构建本构模型,为韧带的损伤预估及替代材料的研发提供参考。方法 通过万能拉伸试验机测试兔髌韧带在不同应变率(0.001、0.01、0.1、1 s^(-1))下的压缩力学性能和压缩松弛响应,并构建相应的本构方程。结果 单轴无侧限压缩实验表明,随着应变率增加,30%、40%应变下的应力和切线模量均明显增大。相比于Gent模型,Fung和Ogden模型更适用于拟合韧带压缩曲线(R2>0.99);采用4项Prony级数更适用于拟合韧带的松弛曲线(R2>0.99)。结论 兔髌韧带的压缩力学性能有显著的黏弹性响应,Fung和Ogden模型可用于拟合韧带的压缩响应,4项Prony级数可用于拟合兔髌韧带的压缩松弛响应。

Objective To investigates the stress-strain relationship of ligaments under compression at different strain rates and construct a constitutive model, so as to provide references for prediction of ligament injury and development of replacement materials. Methods The compressive mechanical properties and compressive relaxation responses of rabbit patellar ligaments at different strain rates(0.001, 0.01, 0.1, 1 s^(-1)) were tested by universal tensile testing machine, and the corresponding constitutive equations were constructed. Results The uniaxial unconfined compression experiment showed that the stress and tangent modulus under 30% strain and 40% strain increased obviously with the increase of strain rate. Compared with the Gent model, the Fung model and Ogden model were more suitable for fitting the ligament compression curves(R~2>0.99). The four-term Prony series were more suitable for fitting relaxation curves of the ligaments(R~2>0.99). Conclusions The compressive mechanical properties of rabbit patellar ligaments demonstrate the significant viscoelastic response. The Fung model and Ogden model can be used to fit compressive response of the ligaments, and the four-term Prony series can be used to fit the compressive relaxation response of rabbit patellar ligaments.