ESTIMATION　OF　FATIGUE　LIFE　UNDER　RANDOM　LOADING　WITH　PLASTIC　HYSTERESIS　ENERGY　THEOREM  

作　　者：Wu Fumin(Northwestern Polytechnical University, Xi’an, China, 710072)ian Dingshuan(Chinese Flitrht Test Establishment, Xi’an, China, 710089) 

出　　处：《Chinese Journal of Aeronautics》1994年第4期289-294,共6页中国航空学报（英文版）

摘　　要：Fatigue damage of materials includes static damage and cyclic damage.Static damage is a ratio of the plastic energy in first static loading to the statictoughness, while cyclic damage is the ratio of the cyclic plastic hysteresis energy to thefatigue toughness. In the calculation, cyclic hardening (or softening) of a material istaken into account, which results in the increase (or decrease) of the yield stress. Forsimplification, it is assumed that stress and strain in cyclic loading vary in accordancewith the hysteresis loop. Fatigue toughness of a material can be detennined bysymmetric cyclic stress controlled fatigue test. A method, rational and convenient forengineering, is proposed to estimate the fatigue life under random loading based onplastic hysteresis energy theorem. Preliminary verification by test is satisfactory.Fatigue damage of materials includes static damage and cyclic damage.Static damage is a ratio of the plastic energy in first static loading to the statictoughness, while cyclic damage is the ratio of the cyclic plastic hysteresis energy to thefatigue toughness. In the calculation, cyclic hardening (or softening) of a material istaken into account, which results in the increase (or decrease) of the yield stress. Forsimplification, it is assumed that stress and strain in cyclic loading vary in accordancewith the hysteresis loop. Fatigue toughness of a material can be detennined bysymmetric cyclic stress controlled fatigue test. A method, rational and convenient forengineering, is proposed to estimate the fatigue life under random loading based onplastic hysteresis energy theorem. Preliminary verification by test is satisfactory.

关 键 词：plastic deforniation static characteristics fatigue tests fatigue life random loads 

分 类 号：V215.5[航空宇航科学与技术—航空宇航推进理论与工程]