This dissertation presents a hypoelastic constitutive model with four material constants in describing the mechanical behavior of granular materials under loading . analysis results of the model have good coincidence with those of triaxial experiment of the standard sand under different relative density . the model can describe the contractant and dilatant phenomena of granular materials 提出了一种含4个材料常数的亚弹性本构模型，来描述散粒体在加载时的力学行为，本模型的分析结果与不同相对密度下标准砂的三轴实验可较好地吻合，能反映散粒体的剪缩、剪胀现象，还对如何用三轴实验数据来确定这4个材料常数，给出了适宜的计算方法。
