沥青混合料蠕变试验数据处理与粘弹性计算

Data processing and viscoelastic computation for creep test of asphalt mixture

为了获得沥青混合料粘弹性本构关系,并利用这种本构关系进行各种数值计算,结合贯入试验中采集到的蠕变数据,采用Matlab软件对蠕变柔量进行拟合,得到了由广义Maxwell模型和Burgers模型表示的粘弹性参数;针对ANSYS有限元软件的计算要求,推导了将其转化为Prony级数形式的计算公式.通过实例计算表明:四参数Burgers模型和六参数Maxwell模型的拟合相对误差分别小于0.7%和1.3%,利用Prony级数方法得到的计算结果与理论解误差不大于0.001%.Burgers模型比广义Maxwell模型更能准确表达沥青混合料的本构关系;Prony级数的转化公式方法简单,计算精确.

In order to obtain the constitutive equations of asphalt mixture and to apply them easily into numerical simulations, creep compliance is fitted here by Matlab software through analyzing creep data acquired in penetration test of asphalt concrete, thereafter, viscoelastic parameters of two models-Burgers and generalized Maxwell model are achieved. Also, based on the requirement of ANSYS software, an algorithm is deduced to transform the constitutive equations into Prony series. An example of penetration test is offered to evaluate the error percentage. As a result, relative errors of Burgers model（ four parameters） is less than 0. 7%, while Maxwell model（ six parameters） less then 1.3 %, and the solution error using Prony series is no more then 0. 001% compared with the theoretical solution. So, it can be proved that the Burgers model is more accurate than generalized Maxwell model in expressing the viscoelastic behavior of asphalt mixture, and the transformation formula to Prony series is simple and efficient.