移动荷载下沥青路面双Top-Down裂纹扩展特性

发布时间：2018-04-29 08:05

  本文选题：沥青路面 + Top-Down裂纹　； 参考：《沈阳建筑大学学报(自然科学版)》2017年02期

【摘要】：目的研究沥青路面双Top-Down裂纹在移动荷载作用下的扩展特性.方法基于断裂力学与动力学理论,考虑沥青混合料的黏弹性特性,采用有限元数值模拟方法,研究含双Top-Down裂纹沥青路面在移动荷载下的动力响应,分析裂纹间距与面层材料类型对裂纹尖端应力强度因子的影响.结果在移动荷载的作用下,双裂纹并存时面层加速发生Ⅰ、Ⅱ型开裂扩展要比单裂纹的情形更为严重;对于居中裂纹,随着裂纹间距的增大,K_Ⅰ的峰值略有增加,而KⅡ的左峰值逐渐增大,右峰值则逐渐减小;对于侧边裂纹,K_Ⅱ峰值随裂纹间距的变化规律与居中裂纹相反;当荷载作用在居中裂纹或侧边裂纹正上方时,就裂纹间距而言,间距大易引发Ⅰ型裂纹扩展,间距小易引发Ⅱ型裂纹扩展.结论在移动荷载作用下,对于已存在居中裂纹或侧边裂纹的面层,改性沥青SMA材料Ⅰ的抗开裂扩展性能最优,改性沥青AC材料Ⅲ其次,而普通沥青AC材料Ⅱ最差.
[Abstract]:Aim to study the propagation characteristics of double Top-Down cracks in asphalt pavement under moving load. Methods based on the theory of fracture mechanics and dynamics, considering the viscoelastic properties of asphalt mixture, the dynamic response of asphalt pavement with double Top-Down cracks under moving load was studied by finite element method. The influence of crack spacing and surface material type on the stress intensity factor at crack tip is analyzed. Results under the action of moving load, the acceleration of mode 鈪，

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