【摘要】 本文提出了一种计算三维结构瞬态温度、位移和热应力的近似方法——等效时间法。利用事先得出的热边界幅值的单位变化所引起的结构响应的有限元分析结果,通过简单的代数运算即可求出同样热边界模式下热边界幅值的任意变化过程在结构中产生的响应。这种近似方法有很高的计算效率。通过算例表明,与详细的有限元计算结果相比,在工程允许的范围内误差满足工程需要。等效时间法可用于对计算效率要求较高的复杂结构的实时分析和设计阶段对各种起动、停机方案的比较和寿命预测。更多还原

【Abstract】 The equivalent time method (ETM) for approximate calculation of the transient temperatures displacements and thermal stresses in 3-d structures is proposed in this paper. Based on the finite element results of structure responses prepared in advance due to one unit variation of thermal boundary, the responses due to any variant history of thermal boundary with the same thermal boundary modal in the structure can be acquired by simple algebraic calculations. Therefore, this approximate method has a highly calculation efficiency. The temperature, displacement and stress predictions by using ETM shows a good agreement with results from the finite element method and may meet the need of accuracy in engineering, analysis. The present method may be applied to the realtime analyses for complicated structures in on-line fatigue monitoring, and provides and effective technique basis for further calculation of fatigue usage fraction and evealuation of remaining life of equipment.更多还原