基于权函数法的沥青混合料预切口小梁的断裂理论与裂纹扩展试验的研究  

Study on Fracture Theory and Crack Propagation Test of Asphalt Mixture Pre-notched Beam Based on Weight Function Method

作　　者：李萍[1] 马科[1] 念腾飞 吴中[1] 郭云枫 

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]甘肃第七建设集团股份有限公司基础桥梁市政工程公司,甘肃兰州730000

出　　处：《公路交通科技》2016年第5期21-27,共7页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51108222);甘肃省科技支撑项目(1504GKCA031)

摘　　要：为研究沥青面层底部裂缝的应力状态和扩展规律,基于权函数法对含单边裂纹的矩形板权函数进行了理论推导,基于切口小梁的试验模型和单边预切口小梁的三点弯曲试验,研究Ⅰ-Ⅱ型应力强度因子、Ⅰ-Ⅱ复合型断裂判据和裂纹在沥青混合料中的扩展变化规律。结果表明:相同的荷载作用下,切口越靠近加载点,Ⅰ型应力强度因子和最大能量释放率越大,Ⅱ型应力强度因子和开裂角越小;切口越长,最大能量释放率越大,小梁越容易开裂;在切口不对称的情况下对小梁加载出现了Ⅰ-Ⅱ复合型开裂,且起裂荷载随着切口偏离加载点距离的增大而增大。通过理论计算与数值模拟结果的对比,使用权函数法计算小梁Ⅰ-Ⅱ复合型裂纹应力强度因子具有良好的精度。In order to research the stress state and the crack propagation of asphalt surface course bottom,the weight function of rectangular plate with single edge crack is derived based on weight function method,the I- II mixed mode stress intensity factor,mixed mode fracture criterion and propagation law of crack in asphalt mixture are studied based on the test model of pre-notched beam and three-point bending test of single-edge notched beam. The result shows that（ 1） under the same load,with the notch closes to the loading point,stress-intensity factor and the maximum energy release rate of mode I increase while the stressintensity factor and the fracture angle of mode II decrease;（ 2） the longer the notch,the greater the maximum energy release rate and the easier the beam to be cracked;（ 3） the mixed-mode cracking appears in the case of asymmetric notch,and the initial cracking load increases with the increase of notch offset distance. Comparing the theoretical and simulation results,it has a good precision to calculate the crack stress intensity factor of the beam by weight function method.

关 键 词：道路工程 沥青混合料 权函数法 裂纹扩展:预切口小梁 应力强度因子 

分 类 号：U416.217[交通运输工程—道路与铁道工程]