CAJ | 학술논문

铝合金蒙皮表面上出现的广布疲劳损伤极易引起结构的剩余强度降低而发生破坏，采用平均应力准则方法，对不同裂纹深度和裂纹间距的多裂纹损伤结构进行了剩余强度有限元模拟分析，分别讨论了在相同裂纹深度与不同裂纹间距、相同裂纹间距与不同裂纹深度、不同裂纹间距与不同裂纹深度对剩余强度的变化规律。结果表明：平均应力准则的计算值与塑性连通准则的计算值误差在1％左右；当裂纹连通间距以2 mm逐步减少时，剩余强度以10 M Pa的幅度逐步减少；当裂纹深度与结构厚度之比低于40％时，剩余强度的下降幅度为40 M Pa左右，否则，剩余强度的下降幅度为20 M Pa左右；当裂纹深度达到板厚50％时，裂纹间距对剩余强度的影响几乎为零。因此，采用平均应力准则方法可以对铝合金蒙皮的多裂纹深度、间距和剩余强度进行预测和评估。
려합금몽피표면상출현적엄포피로손상겁역인기결구적잉여강도강저이발생파배，채용평균응력준칙방법，대불동렬문심도화렬문간거적다렬문손상결구진행료잉여강도유한원모의분석，분별토론료재상동렬문심도여불동렬문간거、상동렬문간거여불동렬문심도、불동렬문간거여불동렬문심도대잉여강도적변화규률。결과표명：평균응력준칙적계산치여소성련통준칙적계산치오차재1％좌우；당렬문련통간거이2 mm축보감소시，잉여강도이10 M Pa적폭도축보감소；당렬문심도여결구후도지비저우40％시，잉여강도적하강폭도위40 M Pa좌우，부칙，잉여강도적하강폭도위20 M Pa좌우；당렬문심도체도판후50％시，렬문간거대잉여강도적영향궤호위령。인차，채용평균응력준칙방법가이대려합금몽피적다렬문심도、간거화잉여강도진행예측화평고。
Widespread fatigue damages in the aircraft skin of aluminum alloy will reduce the structural residual strength easily and accordingly lead to failure .Structures with multiple crack damages varied in depth and spacing were studied by finite element a‐nalysis(FEA) ,employing the average stress criterion method of residual strength .The pattern of residual strength was discussed respectively with different depth and the same spacing ,different spacing and the same dcpth ,and different depth and spacing both .The error is about 1% between the calculations in accordance with average stress criterion and plastic connectivity criterion . The residual strength declines accordingly in the pace of 10 MPa ,when the distance of crack narrows every 2 mm .The residual strength declines around 40 MPa ,when the ratio of crack depth to structural thickness is blow 40% .Otherwise ,the residual strength declines by around 20 MPa .However ,the crack spacing had little influence on the residual strength when cracks pene‐trated beyond half thickness of the structure .The employment of the average stress criterion is efficient in prediction and assess‐ment of cracks and residual strength of aluminum alloy skin .