7075铝合金板材残余应力深度梯度的评估

 提高航空结构件残余应力的测试精度, 意味着可提高其安全可靠性, 减轻重量及降低成本, 然而现有的残余应力测试方法( 如钻孔法、X 射线法等) 只能测定构件外表面与浅表层的残余应力。为此, 引进一种被称为裂纹柔度法的残余应力测试新技术, 对7075 铝合金板材在T73, T7351, T7352 与T7353 状态下的内部残余应力进行了专门研究与评估。有关研究结果表明, 这种残余应力测试新技术不仅能测定7075 铝合金板材的全厚度残余应力分布及其应力梯度, 而且比逐层钻孔法与X 射线衍射法具有更好的敏感性和精确度。

Evaluation of Residual Stress Depth Profiling in 7075 Aluminum Alloy Plates

The ability to accurately evaluate residual stresses will lead to stronger, lighter, longer lasting and cheaper components in aircraft industry. However, the common residual stress measurement methods ( e.g. hole drilling method and X ray diffraction method) are only useful to measure the surface or subsurface residual stresses. With this in mind, the current research program is to introduce the crack compliance method to characterize interior residual stresses in rolled 7075 aluminum plates procured in T73,T7351,T7352 and T7353 temper designations. Experimental results revealed that this newly proposed method can be used to evaluate through thickness residual stresses of 7075 aluminum plates. It further showed that measured subsurface stresses are more sensitive and accurate than those obtained by the incremental hole drilling method or X ray diffraction method.