Detection of Residual Stress in Aluminum Alloy Carbody of High-Speed Train Using X-ray Diffraction Technology

In order to test the surface residual stress in the aluminum alloy carbody of high-speed trains accurately, quickly, and non-destructively, the tensile test of an equal strength rod was used to calibrate the measurement of X-ray diffraction (XRD) method. The residual stress values of welded joints in the aluminum alloy carbody of a high speed train were detected separately by XRD method, blind hole-drilling method, and finite element method (FEM), and then compared with each other. The results show that during the tensile test of the equal strength rod sample, the stress value measured by XRD method well accords with the tensile loading stress in the range of 10 to 70 MPa, and hence the XRD method can be used for testing the residual stress in the key parts of the aluminum alloy carbody of high speed trains. In addition, the numerical values of residual stress detected by XRD method are slightly higher than those obtained by theoretical calculation and electrical measuring method. The maximum residual stress of welded joints in high speed train aluminum alloy vehicle roof is approximately 146.3 MPa. The residual stress results detected by XRD method are in good agreement with those by the equal strength rod tensile calibration, blind hole-drilling method, and FEM.