胫股关节半月板松弛函数的实验研究

EXPERIMENTAL STUDY ON THE RELAXATION FUNCTION OF MENISCUS IN FEMUR-TIBIA JOINT

目的 研究正常国人急性外伤致死的成人新鲜尸体半月板的力学性质 ,为临床提供生物力学参数。方法 对 5具正常国人新鲜尸体胫股关节半月板的一维拉伸力学性能和拉伸应力松弛粘弹性力学性质进行测试。结果 得出了半月板一维拉伸的破坏载荷、伸长比、Lagrange张应力、La grange张应变等实验数据。以多项式用最小二乘法对拉伸实验数进行拟合 ,得出了半月板的应力 应变关系表达式和应力 应变曲线。获得了半月板应力松弛曲线和数据 ,归一化应力松弛函数数据和曲线 ,以及半月板的G(t)表达式。根据准线性理论还得出了髌骨软骨的松弛函数K(λ、t) =G(t)T(e) (λ)的表达式。结论 髌骨软骨单向拉伸最大载荷为 40± 3N ,伸长比为 1 .3 69± 0 .0 48,张应力为 7.2 7± 0 .5 9MPa ,应变为 43 .8± 6.6%。应力松弛主要发生在 1 2 0 0s以内。应力松弛曲线是以对数关系变化的。

Objective To investigate the biomechanical behavior of human knee meniscus. Methods Human fresh meniscus was obtained from death fresh bodies caused by fulminant trauma. One-dimensional tensile test and stress relaxation test were performed. Results The destructive load?stretchy ratio?Lagrange spreading stress?Lagrange spreading strain were obtained. The data of stress and strain was fitting with polynomial by the least square method. In addition, the equation of stress relaxation was also obtained. Based on Feng YZ's the semi-linear theory G(t) formula, the constitutive equation K(λ,t)=G(t)T (e) (λ) was obtained. Conclusion destructive load in one-directional tensile test is 40±3N, the stretchy ratio is 1.369±0.048, the spreading stress is 7.27±0.59MPa and the strain is 43.8±6.6%; Stress relaxation occurs during the first 1200 second and the stress relaxation curve is the logarithmic relation relative to time.