Gkouti Elli, Yenigun Burak, Czekanski Aleksander
Department of Mechanical Engineering, Lassonde School of Engineering, York University, Toronto, ON M3J 1P3, Canada.
Materials (Basel). 2020 Sep 29;13(19):4333. doi: 10.3390/ma13194333.
For viscoelastic materials, the relationship between stress and strain depends on time, where the applied strain (or stress) can be expressed as a step function of time. In the present work, we investigated two temporary effects in the response of viscoelastic materials when a given strain is applied and then removed. The application of strain causes a stress response over time, also known as relaxation. By contrast, recovery is the response that occurs following the removal of an applied stress or strain. Both stress and relaxation constitute transient stages of a viscoelastic material exposed to a permanent force. In the current work, we performed several experimental tests to record the recovery in response to the total or partial removal of the strain. By observing and analyzing the mechanical response of the material to strain, we deduced that recovery is a procedure not only related to creep but also to relaxation. Hence, we created a model that simulates the behavior of viscoelastic materials, contributing to the prediction of relevant results concerning different conditions.
对于粘弹性材料，应力与应变之间的关系取决于时间，其中施加的应变（或应力）可表示为时间的阶跃函数。在本研究中，我们研究了在施加并随后去除给定应变时，粘弹性材料响应中的两种瞬时效应。应变的施加会随时间引起应力响应，这也被称为松弛。相比之下，恢复是在去除施加的应力或应变后发生的响应。应力和松弛都构成了粘弹性材料在受到恒定力作用时的瞬态阶段。在当前的研究中，我们进行了多项实验测试，以记录对应变全部或部分去除的恢复情况。通过观察和分析材料对应变的力学响应，我们推断恢复不仅是一个与蠕变有关的过程，而且还与松弛有关。因此，我们创建了一个模拟粘弹性材料行为的模型，有助于预测不同条件下的相关结果。
