雌性猪尿道壁应力应变关系的测量:预测女性尿道壁排尿期力学变化

Stress-strain Relationship Test of Female Pig's Urethra Wall:Estimating the Mechanical Changes of Female Human's Urethra Wall in Urination

目的研究雌性猪尿道壁的应力应变关系,仿真预测女性排尿过程中力学变化。方法将雌性猪尿道壁样品拉伸直至断裂,测量拉伸过程中拉力和变形,计算应力应变关系、极限应变和极限应力,并统计分析。结果对应力-应变曲线使用二次多项式进行拟合,得到表达式σ=aε2+bε(σ为应力,ε为应变,a=0.3727±0.1471,b=-0.0735±0.0767),决定系数R2=0.9935±0.0034,极限应变为1.096±0.3099,极限应力为(0.3469±0.1974)MPa。结论尿道组织的弹性模量随变形增加而增加。对女性正常排尿生理过程进行仿真计算,尿道的壁应力为2.226×10-3MPa,应变为0.4507,弹性模量为0.5536MPa。

Objective To study on stress-strain relationship in female pig＇s urethra wall and to calculate the mechanical changes in the course of female human＇s urination. Methods The tissue sample of urethra wall was tensed until broke, and the data of the load ＆ elongation in course were recorded. The stress-strain relationship, ultimate strain and ultimate stress were calculated and analyzed. Results Second-order polynomial curve was used to fit the stress-strain curve and the formula was σ = aε^2 ＋ bε （ σ meaned stress, ε meaned strain,a, b were parameters, a = 0. 3727 ± 0. 1471, b = - 0. 0735 ± 0. 0767 ）. This fitting formula had coefficient of determination R^2 = 0. 9935 ±0. 0034. The ultimate strain was （ 1. 096 ± 0. 3099） and ultimate stress was （0. 3469 ± 0. 1974） MPa. Conclusion As the elongation of urethra wall increases,its elastic modulus increased accordingly. The calculated results in the course of urination are the stress of 2. 226 × 10^-3 MPa,the strain of 0. 4507 and the elastic modulus of 0. 5536 MPa.