基于梁理论的涡轮冷却叶片蠕变计算

Creep calculation of turbine cooling blade based on the beam theory

提出一种以梁理论为基础,采用累积损伤理论,利用材料的拉逊-米勒曲线方程计算给定外载荷作用下的等效应力,然后再利用材料的蠕变曲线计算涡轮叶片蠕变变形的方法。使用该方法对航空发动机燃气涡轮工作叶片在经历5个工况后叶尖的蠕变伸长量的平均值进行计算,并与发动机持久试车结果进行对比。结果表明,该方法所得叶尖平均蠕变伸长量与试车后的叶尖最大残余变形的误差为14.0%,验证了该方法在一定精度范围内的有效性。

A new method was proposed which based on the beam theory,using the cumulative damage theo ry and the heat strength parametric equation at a given equivalent stress under the action of external load to get the equivalent stress,and then using the material creep curves to calculate the turbine blade creep.The average residual deformation of a certain type of engine turbine blade tip after five working condition were calculated using this method.The calculation results were compared with the endurance test results.The re sults show that the error between the average creep elongation of the blade tip obtained by the method and the maximum residual deformation of the blade tip after test run is 14.0%,which verifies the effectiveness of the method within a certain precision range.