摘要
为研究荷载作用对应力吸收层厚度和模量的影响,文章采用二维有限元对应力吸收层进行了下基层裂缝尖端I型和II型应力强度因子的计算。结果显示:车辆荷载作用不易导致半刚性基层裂缝上的沥青层发生张开型的反射裂缝;未设置应力吸收层的裂缝尖端的应力强度因子比设置应力吸收层的裂缝尖端的应力强度因子大0.011 6 MPa·m^(1/2),应力吸收层结构削减了基层裂缝尖端剪应力的奇异性,可以延缓基层既有裂缝向沥青扩展;半刚性基层裂缝尖端应力集中因子KⅡ的大小对于应力吸收层的材料模量比结构厚度更为敏感。综合考虑应力吸收层的应力吸收功能,应力吸收层厚度推荐为2cm,而应力吸收层模量的选择则推荐为400~600 MPa。
In order to study the effect of load action on the thickness and modulus of stress absorbing layer,this article used two-dimensional finite element method to calculate the stress intensity factor of type Ⅰ and Ⅱ at the crack tip of lower base for stress absorption layer.The results showed that the vehicle load is not easy to cause the open-type reflection cracks of asphalt layer on the semi-rigid base cracks;the stress intensity factor at the crack tip without stress absorbing layer is 0. 011 6 MPa · m1/2 larger than the stress intensity factor at the crack tip with stress absorbing layer,and the structure of stress-absorbing layer reduces the singularity of the shear stress at the crack tip of base layer,which can delay the expansion of existing base-layer cracks to the asphalt; the size of stress concentration factor K Ⅱ at the crack tip of semi-rigid base layer is more sensitive to the material modulus of stress absorbing layer than structural thickness. Considering the stress absorption function of stress absorbing layer,the thickness of stress absorbing layer is recommended to be 2cm,white the choice for the modulus of stress absorbing layer should be 400- 600 MPa.
出处
《西部交通科技》
2017年第6期43-48,共6页
Western China Communications Science & Technology
关键词
应力吸收层
有限元
半刚性基层
裂缝
Stress absorption layer
Finite element
Semi-rigid base
Cracks
