多遍冲击碾压动荷载作用下路面板力学响应分析

MECHANICAL RESPONSE OF CEMENT CONCRETE PAVEMENT UNDER IMPACT ROLLER COMPACT LOAD AT DIFFERENT TIMES

  • 摘要: 基于三维动力弹塑性有限元分析方法,对冲击压路机沿面板纵向中线及板边两种行驶路线,冲击碾压破碎旧水泥混凝土板时路面板在不同冲击遍数下的变形、受力及破坏特征等力学响应进行了分析。研究发现板边线路板竖向变形明显大于沿板中线路。随着冲击遍数增加路面板呈整体下沉的趋势,最大竖向位移逐渐增大,渐趋稳定;板底冲击轮作用点下方为拉应力区,周围边界局部存在受压区域,纵向相应主拉应力小于横向主拉应力;各工况下路面板表面未出现明显的塑性区,路面板底面均有不同程度的塑性破坏。板边线路最大塑性应变值较板中线路大,但板底的塑性区明显小于板中线路。冲击破碎时,最原始的塑性区首先出现在板底,随着冲击破碎遍数增加,塑性区在面板底部塑性区的基础上逐渐向板面向外发展。

     

    Abstract: Based on a dynamic 3-D finite element method, the deformation, stress and damage characteristics of a pavement slab with different impacting times were studied under the condition of impactor roller running along the longitudinal middle and side route of the slab. It is found that the slab undergoes a larger vertical displacement for the case of the side route than for the middle route. The pavement had the integral sinking tendency, and the maximum vertical displacement of the slab ascends with a decelerating trend and tend to stabilization as the impact times increased; underneath the loading point the slab bottom was in tension with compression zones around the point, and the longitudinal principal tensile stress was larger than the lateral one; there was no significant plastic section on the slab surface but it occurred on the slab bottom. The maximum plastic strain along the side route was larger than the middle route with larger plastic section. During impact rolling, the most originated plastic section was found on the slab bottom, and the plastic section was developed from the slab bottom to the top as the number of impact times increased.

     

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