老化沥青混合料粘弹性疲劳损伤模型研究

RESEARCH ON VISCOELASTIC FATIGUE DAMAGE MODEL OF AGING ASPHALT MIXTURES

  • 摘要: 为了较真实反映沥青路面服务期的疲劳损伤特性,从粘弹性材料的基本特性出发,通过本构方程和耗散能的定义构造了耗散能的泛函,定义耗散能为损伤变量,建立基于Burgers模型的老化沥青混合料粘弹性疲劳损伤模型,通过直接拉伸试验确定沥青混合料的粘弹性参数,求出损伤函数、损伤演化方程,提出一种考虑疲劳过程中老化程度对疲劳损伤影响的累积疲劳损伤计算理论与方法,为沥青混合料在不同老化程度下的疲劳寿命预估提供了依据。根据疲劳损伤模型推导出沥青混合料临界损伤度、疲劳寿命计算公式,并对其进行计算比较,精度满足要求,从而验证了粘弹性疲劳损伤模型的合理性。

     

    Abstract: In order more practically to reflect the fatigue damage characteristics of the asphalt pavement during the course of service,from the basic characters of viscoelastic material, the dissipation functional is constructed based on the constitutive equation and the definition of dissipation energy. Taking definite dissipation energy as a damage variable, the viscoelastic fatigue damage model is established for aging asphalt mixture based on Burgers model. The viscoelastic parameters are identified through Direct Tensile Test. The damage function and damage evolution equation are calculated. The calculation theory and method of cumulative fatigue damage, which consider the aging effects to the fatigue damage, are proposed. It provides a basis for fatigue life predictions about the asphalt mixture under different aging degrees. The critical fatigue damage degree and fatigue life calculation formula are derived by employing the fatigue damage model, which are calculated and compared, the accuracy meets the requirements, which verifies the rationality of the viscoelastic fatigue damage model.

     

/

返回文章
返回