混凝土材料的非线性单轴动态强度准则

本文在混凝土材料单轴动态强度试验研究成果的基础上，提出了混凝土材料强度增长幅值的动力增长因数与对数应变速率之间关系的微分方程，进而建立了混凝土材料的非线性单轴动态强度准则，即J准则。在此基础上，通过引入强度增长幅值的最大动力增长因数，将J准则改进为能描述混凝土材料动态峰值强度特性的S准则。利用国际上已取得的混凝土材料单轴动态强度试验结果对J准则和S准则进行了验证，并与双线性动态强度准则比较，表明J准则与S准则都可较好地描述混凝土材料的非线性动态强度特性，J准则和S准则材料参数少，具有统一的表达式，强度曲线连续光滑，且S准则可反映混凝土材料单轴动态极限强度。

A non-linear uniaxial dynamic strength criterion for concrete

This paper proposes a differential equation between dynamic increasing factor of strength increasing amplitude and logarithm strain rate of concrete based on research results of uniaxial dynamic strength tests. Further, a non-linear uniaxial dynamic strength criterion of concrete is established, namely the J criterion. Based on which, the authors introduce a maximum dynamic increasing factor of strength increasing amplitude to improve the J criterion to the S criterion, that describes dynamic peak strength characteristics of concrete. Verification of the J criterion and the S criterion are completed using published results of uniaxial dynamic strength tests of concrete in international literature. And compared with the bilinear uniaxial dynamic strength criterion, the results show that both the J criterion and the S criterion are able to describe nonlinear dynamic strength characteristics of concrete with satisfactory. And they are with less parameters, a unified expression and continuous smooth strength curve. Further, the S criterion is able to take consideration in uniaxial dynamic limit strength of concrete.