高温构件蠕变损伤分析的龙格-库塔-曼森算法

对于工程中常见的高温构件蠕变问题，本文提出了一种结合龙格-库塔-曼森积分算法的分析方法。该算法中耦合了连续损伤力学本构模型，并修正了hayhurst等人所提公式中的错误。文中给出了积分时间步长自动选择和接受的准则以及失效高斯点的处理方法。本文的算法概念明确，与广泛使用的欧拉法相比，具有计算精度高、速度快和编程方便等优点。因此，本文方法可以预测高温构件剩余寿命以及蠕变裂纹开裂和扩展。文中给出厚壁圆筒蠕变断裂数值算例，计算结果证明了该算法的高效和正确性。

A Runge-Kutta-Merson Algorithm forCreep Damage Analysis of High Temperature Components

Creep problems of high temperature components are often encountered in engineering analysis. A Runge-Kutta-Merson numerical integration algorithm for creep damage analysis was presented in this paper. The continuum damage constitutive model was implemented in the algorithm. A number of mistakes in the similar formulae proposed by Hayhurst have been pointed out and were corrected. In addition, the criteria to choose and accept integration time interval are proposed. The treatment of failed Gauss points was also given. The concept of this algorithm is clear and its programming is easy. Compared with Euler method, the efficiency of solving problems is improved considerably. Thus, the present method is capable of forecasting the remaining life of components at high temperature and suitable for the prediction of creep crack initiation and growth in solids. The validity of computer program is verified and the high efficiency of the proposed algorithm is also demonstrated by the results of a thick cylinder problem subjected to an internal pressure.