应用当量应变法预测多维高温低周疲劳寿命

MULTIAXIAL LOW CYCLE FATIGUE LIFE PREDICTION AT 300℃ USING EQUIVALENT STRAIN APPROACH

采用铝合金材料三维缺口试件进行 3 0 0℃下高温低周疲劳断裂试验 ,借助ADINA程序计算试件缺口周围的三维应力和应变场 ,根据vonMises当量理论对疲劳寿命进行预测。预测结果表明 ,当量应变范围与疲劳断裂寿命的数学关系不受试件缺口型式的影响 。

The low cycle fatigue behavior was experimentally studied with the 3 dimension notched LD8 aluminum alloy specimens at 300℃. The 3 dimension stress strain responses of specimens were calculated by means of the program ADINA. The multiaxial fatigue life prediction was carried out according to von Mises's equivalent theory. The results from the prediction showed that the equivalent strain range can be served as the valid mechanics for predicting multiaxial high temperature and low cyclic fatigue life.