CAJ | 학술논문

基于灰色理论研究DD3镍基单晶合金高温多轴非比例加载低周疲劳特性，对等效应变范围、温度、应变路径角、拉/扭载荷相位角和轴向应变比等影响疲劳寿命的因素进行灰色关联度分析，并引入损伤参量Q表征非对称循环特性和拉/扭多轴效应，以参量Q、等效应变范围Δεe和Mises等效应力范围Δσe构造疲劳损伤参量，建立低周疲劳寿命GM(1, N)预测模型。结果表明，各影响因素与多轴低周疲劳寿命的关联度等级依次为等效应变范围、温度和应变路径角为一级，拉/扭载荷相位角为二级，轴向应变比为三级；680℃和850℃温度下的GM(1, N)疲劳寿命模型的预测寿命与试验寿命的绝对关联度分别为0.97、0.86，平均相对误差分别为4.9%、6.0%；两种温度的试验数据几乎分别落在1.93、2.13倍偏差分布带内。
기우회색이론연구DD3얼기단정합금고온다축비비례가재저주피로특성，대등효응변범위、온도、응변로경각、랍/뉴재하상위각화축향응변비등영향피로수명적인소진행회색관련도분석，병인입손상삼량Q표정비대칭순배특성화랍/뉴다축효응，이삼량Q、등효응변범위Δεe화Mises등효응력범위Δσe구조피로손상삼량，건립저주피로수명GM(1, N)예측모형。결과표명，각영향인소여다축저주피로수명적관련도등급의차위등효응변범위、온도화응변로경각위일급，랍/뉴재하상위각위이급，축향응변비위삼급；680℃화850℃온도하적GM(1, N)피로수명모형적예측수명여시험수명적절대관련도분별위0.97、0.86，평균상대오차분별위4.9%、6.0%；량충온도적시험수거궤호분별락재1.93、2.13배편차분포대내。
Based on grey theory, the characteristics on low cyclic fatigue of DD3 Ni-based single crystal alloy under multi-axial non-proportional loading are researched. Degree of grey incidence of factors influencing fatigue life, such as equivalent strain range, temperature, strain path angle, tension/torsion phase angle, axial strain ratio, is analyzed. A damage parameterQ is introduced to express asymmetric load cyclic characteristic and tension/torsion multi-axial effect. A low cyclic fatigue life prediction model GM(1,N) with parameterQ, equivalent strain rangeΔεe and Mises stress rangeΔσe as damage parameters is built. The results show that degree of grey incidence of influencing factors on multi-axial low cyclic fatigue life,from maximum to minimum,are equivalent strain range , temperature and strain path angle for the first level, tension/torsion phase angle for the second level, and axial strain ratio for the third level. Absolute degree of incidence of test life and predictive life for fatigue model GM(1,N) at 680℃ and 850℃ are 0.97, 0.86, respectively, and mean relative errors are 4.9%, 6.0% respectively. Almost all test data of above-mentioned two temperatures were fall into the factors of 1.93 and 2.13 scatter band, respectively.