Biomedical Engineering Doctoral Program, Boise State University, Boise, ID 83725.
Research Computing Support, Boise State University, Boise, ID 83725.
J Biomech Eng. 2023 Feb 1;145(2). doi: 10.1115/1.4055593.
The calculation of tensile mechanical properties from stress-strain curves is a fundamental step in characterizing material behavior, yet no standardized method exists to perform these calculations for soft tissue. To address this deficiency, we developed a free web application called Dots-on-Plots2 that fully automates the calculation of tensile mechanical properties from stress-strain curves. The analyzed mechanical properties include the strength, strain, and energy at four points of interest (transition, yield, ultimate, and rupture), and the linear modulus. Users of Dots-on-Plots can upload multiple files, view and download results, and adjust threshold settings. This study determined a threshold setting that minimized error when calculating the transition point, where the stress-strain curve "transitions" from a nonlinear "toe" region to a linear region. Using the optimal threshold (2% stress deviation from a linear region fit), Dots-on-Plots calculated the transition strains from twenty tensile experiments of human meniscus to be 0.049 ± 0.007, which nearly matched the known transition strain values of 0.050 ± 0.006 (determined using finite element parameter optimization). The sensitivity of the calculated transition strain to the shape of various stress-strain curves was analyzed using sets of model-generated synthetic data. This free web application offers a convenient and reliable tool to systematically enhance the speed, transparency, and consistency of mechanical analysis across biomedical research groups.
从应力-应变曲线计算拉伸力学性能是表征材料行为的基本步骤,但对于软组织,目前还没有标准化的方法来进行这些计算。为了解决这个问题,我们开发了一个名为 Dots-on-Plots2 的免费网络应用程序,它可以完全自动地从应力-应变曲线计算拉伸力学性能。分析的力学性能包括四个感兴趣点(过渡点、屈服点、最大点和断裂点)的强度、应变和能量,以及线性模量。Dots-on-Plots 的用户可以上传多个文件,查看和下载结果,并调整阈值设置。本研究确定了一个阈值设置,该设置可在计算过渡点时将误差最小化,在过渡点处,应力-应变曲线“从非线性‘脚趾’区域过渡到线性区域。” 使用最优阈值(线性区域拟合的 2%应力偏差),Dots-on-Plots 计算了二十个人半月板拉伸实验的过渡应变值为 0.049 ± 0.007,这与已知的过渡应变值 0.050 ± 0.006(通过有限元参数优化确定)非常接近。通过使用模型生成的合成数据集来分析计算得到的过渡应变对各种应力-应变曲线形状的敏感性。这个免费的网络应用程序为生物医学研究小组提供了一个方便、可靠的工具,可以系统地提高机械分析的速度、透明度和一致性。