一种动态地形实时可视化系统框架

如何构建一个可实时绘制且能尽量满足真实感的动态地形,是虚拟现实领域建立虚拟环境的首要问题之一。作者通过对实时构建逼真动态地形的各种技术难点进行分析和总结,提出了一种动态地形实时可视化系统框架,分为地形数据库模块、动态地形可视化模块、仿真实体-地面交互模块,然后按照该框架构建了一个动态车辙系统,结合现实中车辆和地面的物理属性,通过在平地和山地上动态模拟车辆行驶时实时生成的车辙效果,对该框架进行了验证。实验结果表明该框架具有使系统能够较好的兼备实时性和真实性特点的功能。

Modification of the linear viscoelastic deformation prediction model of asphalt mixture

A deformation prediction model for the dynamic creep test is deduced based on the linear viscoelastic（LVE）theory.Then,the defect of the LVE deformation prediction model is analyzed by comparing the prediction of the LVE deformation model with the experimental data.To improve accuracy,a modification of the LVE deformation prediction model is made to simulate the nonlinear property of the deformation of asphalt mixtures,and it is verified by comparing its simulation results with the experimental data.The comparison results show that the LVE deformation prediction model cannot simulate the nonlinear property of the permanent deformation of asphalt mixtures,while the modified deformation prediction model can provide more precise simulations of the whole process of the deformation and the permanent deformation in the dynamic creep test.Thus,the proposed modification greatly improves the accuracy of the LVE deformation prediction model.The modified model can provide a better understanding of the rutting behavior of asphalt pavement.