水泥稳定碎石疲劳的破坏力学分析

Fatigue Analysis of Cement-stabilized Macadam with Failure Mechanics

结合断裂力学和损伤力学的方法对水泥稳定碎石小梁疲劳寿命进行了分析。用有限元对小梁试件断裂韧度进行了计算,给出了拉应力控制的损伤演化方程,根据小梁疲劳试验的部分数据基于断裂韧度控制指标反算了损伤演化方程的系数,并用小梁疲劳试验的剩余数据对该损伤演化方程的寿命预估精度进行了验证。结果表明,用有限元计算小梁的断裂韧度具有足够的精度,基于断裂韧度为控制指标的损伤演化方程比常用的S-N方程具有更好的寿命预估能力。这种方法对小梁疲劳试验数据分析引入了力学参量,可以为实际道路结构中的寿命预估提供计算模型。

The fatigue life of cement-stabilized macadam specimen beams was analyzed through coupling fracture and failure mechanics. The fracture toughness of specimen beams was calculated by finite element method（FEM）. And the damage evolution equation controlled by tension stress was given, in which coefficients were back-calculated based on the fracture toughness comrol index using partial fatigue tests data. The life prediction precision of this equation was verified using residual fatigue tests data. It was shown that FEM is effective to calculate the fracture toughness of specimen beams. And the damage evolution equation based on the fracture toughness control index had better life prediction ability comparing with the S-N equation. The proposed method can provide a calculation model to predict the service life of practical road structure.