板类构件内部残余应力测试技术研究

为了克服现有残余应力测试技术难以测定工程构件内部残余应力的局限性,提出一种被称为裂纹柔度法的残余应力测试新方法.基于线弹性断裂力学原理,在被测物体表面引入一条深度逐渐增加的裂纹,通过测定零件表面的残余应变释放量来计算7055铝合金板材内部残余应力分布规律.研究结果表明,裂纹柔度法与逐层钻孔法及X射线衍射法相比,具有更好的敏感性和精确度,可用于测定板类构件内部残余应力.

Study on measurement method of interior stress distributions in engineering rolled-plates

To overcome the limit of the common residual stress measurement methods in measuring interior residual stresses in engineering parts, a novel residual stress measurement method known as crack compliance method was introduced. Based on the fundamental theoretical relations of liner-elastic fracture mechanics, a narrow slot normal to the face was machined incrementally into a part to release the residual stresses. After the released strains were measured by surface strain gauges, the interior stress distributions were derived in 7055 aluminum rolled-plates. Experimental results show that the method is more sensitive and accurate than the incremental hole-drilling method and X-ray diffraction method, and suited for measuring interior residual stresses in engineering rolled plates.