聚丙烯纤维水泥砂浆动态力学特性与本构模型研究

通过改进的分离式Hopkinson压杆试验装置对聚丙烯纤维水泥砂浆进行动态力学性能以及动态损伤本构关系的研究.基于试验结果得到的应力一应变曲线,对聚丙烯纤维水泥砂浆在不同应变率下的弹性模量、峰值应力和韧度变化规律进行了探讨.根据试验应力应变曲线的基本特征,选择引入朱-王-唐本构模型,并考虑纤维的阻裂作用,对试验结果进行拟合,提出了一种新的聚丙烯纤维水泥砂浆动态损伤本构模型.该模型在考虑聚丙烯纤维增强、应变率硬化、损伤软化等因素下,描述聚丙烯纤维水泥砂浆的动态受力特性.

Study on dynamic mechanical property and constitutive model of polypropylene fiber cement mortar

The paper used the pressure bar test device of improved split Hopkinson to study the dynamic characteristic and dynamic damage constitutive relation for polypropylene fiber cement mortar. Based on the stress-strain curves, it discussed the variation laws of elasticity modulus, peak stress and toughness of polypropylene fiber cement mortar under different strain rates. According to the basic characteristic of stress-strain curves, the paper introduced ZWT constitutive model and considered the crack resistance of fiber to fit the test result, and proposed a new dynamic damage constitutive model of polypropylene fiber cement mortar. The model can describe dynamic stress characteristic of the mortar under the situation of thinking the reinforcing and strain-rate hardening and damage softening of polypropylene fiber.