Molecular Dynamics Simulations of Polymer Grouting Material: Its Mechanical Behavior under Uniaxial Tension, Cyclic Tensile Loading, and Stress Relaxation
Molecular Dynamics Simulations of Polymer Grouting Material: Its Mechanical Behavior under Uniaxial Tension, Cyclic Tensile Loading, and Stress Relaxation
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聚合物注浆材料的分子动力学模拟：其在单轴拉伸、循环拉伸载荷及应力松弛下的力学行为
DOI：
10.1155/2022/4923385
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发表时间：
2022-09
期刊：
影响因子：
1.7
通讯作者：
Mingrui Du;Haoyue Zhang;Yan Zhao;Zongliang Huang;Chengzhi Zheng;Rui Wu;Xinlei Gao
中科院分区：
文献类型：
--
作者：
Mingrui Du;Haoyue Zhang;Yan Zhao;Zongliang Huang;Chengzhi Zheng;Rui Wu;Xinlei Gao
目前，聚氨酯作为灌浆材料在土木工程中得到了广泛的应用。聚氨酯的力学性能是达到理想灌浆效果的关键。本文采用粗粒化分子动力学模拟方法，对聚氨酯基体在拉伸、连续循环拉伸和应力松弛下的力学行为进行了研究。讨论了分子链数和应变速率对聚氨酯基体拉伸力学性能的影响，揭示了聚氨酯基体的拉伸变形机理。聚氨酯基体的拉伸强度与加载路径无关，屈服后的应变包括弹性应变、塑性应变和粘性应变。在应力松弛过程中，轴向应力的演变主要是由不同的货车德瓦尔斯相互作用引起的。PU基体的应力松弛行为可用一个弹性单元与一个麦克斯韦单元并联组成的粘弹性模型来描述。
At present, polyurethane (PU) has been extensively used as a grouting material in civil engineering. The mechanical properties of PU are the key to achieving the desirable grouting effect. This study presents the research results of the mechanical behavior of PU matrix under tensile, successive cyclic tensile, and stress relaxation at the nanoscale, using the coarse-grained molecular dynamics simulation method. The influences of the number of molecule chains and strain rate on the tensile mechanical properties are discussed, and the tensile deformation mechanism of PU matrix is revealed. The tensile strength of PU matrix is independent of loading path, and after yielding, the strain of PU matrix contains the elastic strain, plastic strain, and viscous strain. In the stress relaxation process, the evolution of the axial stress is mainly caused by the varied van der Waals interactions. The stress relaxation behavior of PU matrix can be described by the viscoelastic model consisting of one elastic element in parallel with one Maxwell element.