几个强度理论的屈服实验研究

COMPARISON OF YIELD STRENGTH THEORIES WITH EXPERIMENTAL RESULTS

根据多种塑性金属的二向和三向拉伸与压缩组合主应力屈服强度实验数据,对Tresca强度理论、Mises强度理论、Mohr-Coulomb强度准则、Beltrami最大能量理论、极限应变能强度理论等几个强度理论计算的相对误差进行了比较分析。结果表明极限应变能强度理论计算的误差在10%以内,为最小。Tresca强度理论、Mises强度理论和Mohr-Coulomb强度准则计算的误差分别为-36%、-27%、-23%,计算结果比试验结果偏保守。Tresca强度理论和Mises强度理论都不适用于拉伸屈服强度和压缩屈服强度相等的材料,该材料的理论剪切屈服强度为拉伸屈服强度的2^(1/2)/2倍。极限应变能强度理论可用于二向和三向拉伸与压缩组合主应力强度计算,在全拉伸和全压缩主应力状态下与Rankine强度理论一致,具有工程应用前景和价值。

On the basis of the testing data of the yield strength of various types of plastic metals under biaxial and triaxial combined tensile-compressive principal stress, the relative errors calculated using Tresca strength theory, Mises strength theory, Mohr-Coulomb strength criterion, Beltrami＇s maximum energy theory and limiting strain energy strength theory （LSEST） are analyzed, respectively. The result shows that the errors according to LSEST are within 10%, being the minimum. The errors calculated by Tresca strength theory, Mises strength theory and Mohr-Coulomb strength criterion are -36%, -27% and -23%, respectively. The calculating results are on the conservative side compared with the test ones. For materials with equal tensile and compressive yield strength, Tresca strength theory and Mises strength theory could not be applied either, and the theoretical shear yield strength is √2 / 2 times of the tensile yield strength. LSEST could be used to calculate the strength under biaxial and triaxial combined tensile-compressive principal stress, which is consistent with Rankine strength theory under a full tensile and a full compressive principal stress state, which suggests that LSEST has a prospect and value for engineering applications.