通过对混凝土多轴应力下强度、变形和破坏形态的大量试验研究，建立了非线弹性正交异性本构模型。根据试验规律，建议了拉应力指标α以划分混凝土的破坏形态，并分别给定适宜的等效单轴应力—应变关系；定义了合理的应力水平指标β；给定拉、压应力状态泊松比值的不同变化规律和公式。本构模型与试验曲线比较，无论是应力—应变曲线的形状和绝对值，以及不同应力比下的峰值应变变化规律都符合良好 Through a large number of experimental studies on the strength, deformation and failure modes of concrete under multiaxial stress, a nonlinear elastic orthotropic constitutive model was established. According to the test law, the tensile stress index α is proposed to divide the failure form of the concrete, and the appropriate equivalent uniaxial stress-strain relationship is given respectively; a reasonable stress level index β is defined; given the tensile and compressive stress states Poisson The ratio of different changes in the law and formula. The comparison between the constitutive model and the test curve shows that both the shape and absolute value of the stress-strain curve and the peak strain change rule under different stress ratios are in good agreement.