半刚性基层沥青路面反射裂缝扩展过程分析的Williams单元  

WILLIAMS ELEMENT FOR REFLECTIVE CRACK PROPAGATION IN ASPHALT PAVEMENT ON SEMI-RIGID BASE COURSE

作　　者：徐华[1] 杨绿峰[1,2] 佘振平[1] 

机构地区：[1]广西大学土木建筑工程学院工程防灾与结构安全重点实验室,广西南宁530004 [2]广西壮族自治区住房与城乡建设厅,广西南宁530028

出　　处：《工程力学》2013年第6期247-253,共7页Engineering Mechanics

基　　金：国家自然科学基金项目(51168003);广西自治区主席基金项目(2010GXNSFD169008);工程防灾与结构安全教育部重点实验室主任基金项目(2009TMZR004)

摘　　要：该文对半刚性基层沥青路面结构采用弹性层状体系平面应变分析模型,利用改进的Williams级数,结合广义参数有限元法和常规等参元,建立了反射裂缝裂尖应力强度因子分析的广义参数Williams单元,并推导了Williams单元的刚度方程,据此研究了正对称荷载和偏载分别作用时,反射裂缝扩展过程中应力强度因子的变化规律;重点分析了偏载作用下路面结构层参数与应力强度因子之间的关系。Williams单元中含有与应力强度因子相关的参数,可以直接获得裂尖应力强度因子。算例分析表明:Williams单元与传统方法的计算结果吻合较好,且格式简单,计算精度高,适用于沥青路面反射裂缝扩展过程分析。This paper presented a Williams element with generalized degrees of freedom （GDOFs） for stress intensity factor （SIF） analysis of reflective crack in asphalt pavement on semi-rigid base course by means of the layered linear elastic plane strain model and isoparametric element. The stiffness equation was developed for Williams element with GDOFs to yield directly the SIF at the reflective crack tip in the asphalt pavement, as the Williams element contains parameters related to the SIF. The SIF variation is investigated during the propagation of reflective cracking under symmetrical and partial load respectively. The influence of the material and geometrical parameters on the SIF was discussed in details. Numerical example shows that the Williams element has the advantage of simplicity as well as high accuracy. Results from the Williams element agree well with those by the traditional quarter-point element, therefore Williams element can be used for SIF evaluation at the reflective crack tip in the asphalt pavement on the semi-rigid base course.

关 键 词：沥青路面 反射裂缝 Williams单元 应力强度因子 半刚性基层 

分 类 号：U416[交通运输工程—道路与铁道工程]