弹射冲击载荷作用下沥青混凝土路面面层的损伤

DAMAGE OF SURFACE LAYER OF ASPHALT CONCRETE PAVEMENT UNDER LAUNCHING IMPACT LOAD

沥青混凝土作为一种粘弹性材料一般只研究其疲劳损伤特性,冲击损伤研究较少。针对路面在弹射载荷作用下产生中低应变率响应的特点,采用Cauchy应变表达的三维简化ZWT(朱-王-唐)非线性粘弹本构模型以及应变率相关的损伤演化模型,建立了增量形式并将Kirchhoff应力转化为Cauchy应力,编写用户材料子程序嵌入有限元软件中。推导了恒应变率条件下含损伤的简化ZWT本构表达式,使用最小二乘法拟合出本构参数。分析了沥青混凝土场坪面层的冲击损伤,阐明了损伤变化规律、分布规律,为发射场坪的选择提供了一定参考。

A 4s a viscoeslastic material, asphalt concrete＇s fatigue damage properties are studied more widely than its impact damage properties. To consider the mid/low-strain rate response produced under launching loads, a three-dimensional simplified ZWT （Zhu-Wang-Tang） model is used to denote material constitutive properties at the impact site. The ZWT model is a non-linear viscoeslastic constitutive relationship, established based on Cauchy strain. Based on the above constitutive model, strain-rate dependent evolution damage model, and their incremental expressions, a user subroutine for the material is compiled and integrated into finite element software. A simplified ZWT model with damage under conditions of unchanged strain rate is deduced and its parameters fitted by the least squares method. The variation law and distribution law of damage are clarified by analyzing impact damage in the surface layer of the asphalt concrete launch site, and the conclusion can serve as a reference in choosing launching sites.