中文摘要：

利用生物材料试验机和套管式高聚物霍普金森拉杆装置,试验得到了猪后腿肌肉在宽应变率范围（0.02～2100s^-1）内沿纤维方向和垂直纤维方向的拉伸应力应变曲线。编写程序对动态试验中高聚物杆波的弥散和衰减效应进行了修正。对试验结果采用了1维方差统计分析,结果发现：应变率从0.02s^-1上升到2100s^-1,肌肉在2个加载方向上流动应力都显著提高,即具有明显的应变率效应;低应变率下,纤维方向的极限强度比垂直纤维方向的大,而破坏应变无显著不同,准静态应力应变曲线的形状与其他软组织类似,开始为＂足趾＂区,后进入线性区,接着又有1段非线性区,最后达到极限强度,试样逐渐破坏;高应变率下,应力应变曲线无＂足趾区＂,这是因为组织中的螺旋结构来不及伸直所致。垂直纤维方向比纤维方向有更高的初始模量,但随应变增加,两者流动应力无显著差别,且纤维方向流动应力有逐渐高于垂直纤维方向的趋势。

英文摘要：

The tensile stress-strain curves of porcine ham muscle along the longitudinal and transverse directions of the muscle fibre were obtained over a wide range of strain rates（0.02～2 100s^-1）.The experiments were performed by using the biomechanical testing system and the polymeric split Hopkinson tensile bar（SHTB）in the tubes.A program was compiled to modify the effect of dispersion and attenuation of waves in the viscoelastic polymeric bar used as the transmission bar in the dynamic experiments.Statistical analyses were done by using one-way ANOVA（p〈0.05）.The results show that the flow stress of the porcine ham muscle at the high strain rate of 2 100s^-1 is both apparently higher than that at the low strain rate of 0.02s^-1 along the two loading directions,illustrating the strain rate sensitivities of the porcine ham muscle.At the low strain rates,the ultimate strengths along the longitudinal direction are higher than those along the transverse direction,whereas there are no significant differences between their failure strain values.The quasi-static stress-strain curves behave as the other soft tissues,exhibiting an initial non-linear＂toe＂region,followed by a linear region and subsequently a nonlinear region prior to the gradual failure.At the high strain rates,the＂toe＂region vanishes because it has no enough time to permit the straightening of the helical structure.The initial modulus in the transverse direction is much higher than that in the longitudinal direction.However,when the strain increases,the flow stresses in the two directions have no significant difference and the flow stress in the longitudinal direction gradually inclines to higher than that in the transverse direction.