移动分布荷载下层状粘弹性体系的动力响应分析

以粘弹性Burgers模型模拟沥青面层,建立了路面结构层状粘弹性体系模型。利用积分变换和传递矩阵法,并结合广义Duhamel积分,推导出了移动分布荷载作用下层状粘弹性体系动力响应的解析解。利用样条插值函数开发了计算奇异、振荡函数多重无穷积分的计算程序,完成了动力响应从波数-频率域到时间-空间域的转化,与已有文献数据和有限元结果进行了比较,显示出了较好的一致性。结合算例分析了移动分布荷载作用下层状粘弹性体系的振动特性。结果表明,粘弹性解大于弹性解,Burgers模型能反映沥青路面变形的滞后现象,层状粘弹性体系的垂向位移随行车速度和Burgers模型材料参数的增加而减小。

DYNAMIC RESPONSE IN MULTILAYERED VISCOELASTIC MEDIUM GENERATED BY MOVING DISTRIBUTED LOADS

A multilayered viscoelastic medium is established by modeling the asphalt surface course as viscoelastic Burgers constitutive relation. The analytical solutions of dynamic responses in multilayered viscoelastic medium under moving distributed loads are derived by combining the integral transform and transfer matrix method with the generalized Duhamel integral. The spline interpolation numerical algorithm is used to calculate the multiple integrals of singular and oscillatory functions, which transfers the solutions from the wavenumber-frequency domain to the time-space domain. The numerical results are compared with the existing data available in literature and those obtained from ANSYS finite element analysis, and excellent agreement has been observed. The vibration characteristics of the multilayered viscoelastic medium under moving distributed loads are then analyzed through case studies. The results show that viscoelastic solutions are greater than elastic solutions, and Burgers model can reflect the delayed pavement deformation. The vertical displacements of multilayered viscoelastic medium decrease as the vehicle moving speed and Burgers material parameters increase.