无黏性砂土受载累积变形的弹塑性本构模型

基于经典弹塑性本构模型框架和双硬化模型,选用两种不同屈服面,建立了一种无黏性砂土弹塑性本构模型. 该模型能计算履带车辆行驶工况下,地面无黏性砂土受反复载荷作用下的累积变形;另外针对砂土材料在剪切条件下发生剪胀现象,结合剑桥模型的剪胀公式,模型引入无黏性砂土的剪胀性参数,以描述土壤在剪切力作用下的变形. 研究结果表明,该模型能够反映无黏性砂土在车辆行驶过程中的累积塑性变形,便于计算机仿真分析. 

Establishment of Elastic-Plastic Constitutive Model for Non-Sticky Sand Under Vehicle Multi-Load

On the basis of classical elastic-plastic constitutive model framework and double hardening model, we choose two different yield surfaces to establish an elastic-plastic constitutive model of cohesionless sand under vehicle cycle load. The model could reflect cumulative deformation of cohesionless soil with the cycle load. Further, considering the dilatancy phenomenon of sand which occurs under shear condition, the model introduces dilatancy parameter of sand and gives the dilatancy formula of Cambridge model. The research results show that the established model could not only reflect the accumulation plastic deformation of cohesionless sand under the vehicle cyclic load, but also provide the theory basis for developing transportation vehicles or military vehicles with strong passing ability on sand road.