基于线性加载区域的软组织预加载力消除方法

The elimination method of preloading force for soft tissue based on the linear loading region

针对软组织压缩实验中预加载力对其力学响应存在影响的问题,本文提出了一种基于线性加载区域的预加载力消除方法。通过对软组织进行多种预加载力的非受限压缩实验,分析了预加载力对本构模型参数的影响。在预加载阶段,将软组织力学响应作为线性模型,通过将预加载阶段响应考虑到整个响应过程来实现对预加载力的消除。针对非受限压缩实验的5种不同预加载力得到的力学响应,基于两种不同的软组织本构模型对该消除方法进行验证,并对比预加载力消除方法和传统方法得到的模型与实验结果的误差。结果显示消除预加载力方法得到的模型误差要明显小于传统方法,说明预加载力消除方法能够在一定程度上消除预加载力对软组织力学响应的影响,获得更接近软组织真实特性的本构模型参数。

Aiming at the problem of the influence of preloading force on its mechanical response in soft tissue compression experiments, an elimination method of preloading force based on linear loading region is proposed. Unconfined compression experiments under a variety of different preloading forces are performed. The influence of the preloading force on the parameters of constitutive model is analyzed. In the preload phase, the mechanical response of the soft tissue is taken as a linear model. The preloading force is eliminated by taking the preloading phase into account throughout the response process. According to five different preloading forces of the unconfined compression experiments, the elimination method is validated with two different constitutive models of soft tissue, and the error between the models obtained by the preloading force elimination method and the traditional method with the experimental results is compared. The results show that the error obtained by preloading force elimination method is significantly smaller than the traditional method. The preloading force elimination method can eliminate the influence of preloading force on mechanical response to a certain extent, and constitutive model parameters which are closer to the true properties of soft tissue can be obtained.