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总览 评价 于庆民 * （ 西北工业大学力学与土木建筑学院； ） 摘要： 本文以薄壁圆管试样模拟镍基单晶冷却叶片，采用有限元方法模拟了该模拟试样在温度梯度环境下的蠕变变形。蠕变及弹性参数根据国产DD3镍基单晶合金试验结果确定。计算结果表明温度梯度对蠕
于庆民*
（
西北工业大学力学与土木建筑学院； ）
摘要：
本文以薄壁圆管试样模拟镍基单晶冷却叶片，采用有限元方法模拟了该模拟试样在温度梯度环境下的蠕变变形。蠕变及弹性参数根据国产DD3镍基单晶合金试验结果确定。计算结果表明温度梯度对蠕变应力和应变分布有显著的影响。在蠕变过程中，高温区和低温区的应力随着蠕变的进行分别降低和增加，温度越低，应力越大。低温区应力的增加导致了蠕变应变率的增加，同样地，高温区的蠕变应变率随着应力的降低而减小。不同温度区域蠕变应力大小和分布的变化导致了蠕变应变的重新分布。
关键词：
固体力学；镍基单晶合金；温度梯度；蠕变；有限元
YU Qingmin*
（
School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical Univeristy, Xi'an 710072； ）
Abstract：
In this study, thin-walled cylindrical specimen was used to model air-cooled gas turbine blade. The deformation characteristic during creep under temperature gradient was investigated by finite element method. The creep parameters along [001] and elastic constants were taken from the experiment results of nickel-based single crystal superalloy DD3. The results show that the temperature gradient has notable influence on stress and strain distributions during creep. The stress of low temperature zone increases and that of high temperature zone decreases with the development of creep. The lower the temperature is, the higher the stress is. The increase of stress induces the increase of strain rate in low temperature zone. The strain rate in high temperature zone decreases due to the stress drop. The rapid changes of stress value and distribution result in the redistribution of strain in different temperature zone. The crack will appear firstly in low temperature zone for the higher stress and strain.
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