Mechanical Behavior of High-Strength Plastics: Experiments and Modeling

对高强度聚合物固体的变形行为进行了理论和实验相结合的研究。该机械试验机能够施加单向和双向加载路径，并控制加载速率。蠕变、松弛和速率敏感性所表现的随时间变化的行为在这里引起了极大的兴趣。最初，我们希望完成高强度尼龙的单轴研究和同时进行的微结构研究，如X射线衍射研究。将设计和制造一种夹具，以适应承受轴向、扭转和内压载荷的管状试件。然后将选择一种新的测试材料，最好从Xydar或Vectra等聚合物、各向异性液晶中选择，在其上进行单轴和双轴测试以及微观结构研究。在理论部分，我们建议使用由耦合的非线性微分方程组组成的状态变量理论来模拟有限力学变形行为。这项研究的目的是将唯象实验、微观结构研究和连续介质力学结合起来，得到聚合物固体的数学模型。

A combined theoretical/experimental study on the deformation behavior of high strength polymeric solids is proposed. The mechanical testing machine capable of exerting uniaxial as well as biaxial loading paths with controlled loading rates. The time-dependent behavior manifested by creep, relaxation and rate sensitivity is of great interest here. Initially we want to complete a uniaxial study of high strength nylon and concurrent microstructural investigations such as x-ray diffraction studies. A fixture to accommodate tubular specimens subjected to axial, torsional and internal pressure loading will be designed and built. Then a new test material will be chosen, preferably from the class of polymeric, anisotropic, liquid crystals such as Xydar or Vectra, on which uniaxial and biaxial testing and microstructural investigations are contemplated. In the theoretical part we propose to model the finite mechanical deformation behavior using state variable theories consisting of coupled nonlinear differential equations. The aim of the research is to combine synergistically phenomenological experiments, microstructural investigations and continuum mechanics to arrive at a mathematical model of the polymeric solid.