水泥基体中聚乙烯醇(PVA)纤维拔出的数值模拟

Numerical Simulation of Polyvinyl Alcohol (PVA) Fiber Pullout from Cement Matrix

既往数值模拟中,纤维与水泥基体间的粘结滑移关系通常由内聚力模型来表述,但由于聚乙烯醇(PVA)纤维拔出过程中荷载位移曲线的特殊性,仅由内聚力模型难以表征出脱粘后的应变硬化阶段。文中通过分析PVA纤维从水泥基体中拔出全过程,综合滑移硬化效应产生的原因,提出了基于约束不断增大的有限元数值模拟方法,有效地模拟出水泥基体中PVA纤维拔出的全过程曲线。

In the past numerical simulation, the bond slip relationship between fiber and cement matrix is usually described by the cohesive model. However, due to the particularity of the load displacement curve during the pullout process of PVA fiber, the strain hardening stage after debonding is difficult to be characterized by the cohesive model alone.Based on the analysis of the whole process of PVA fiber pullout from the cement matrix and the reasons for the slippage and hardening effect, a finite element numerical simulation method based on the increasing constraints was proposed to effectively simulate the whole process curve of PVA fiber pull-out from the cement matrix.