Measurement of strain distribution around weld zone for railway carbody structure using high-energy synchrotron radiation

Matsumoto, Keisuke*; Shobu, Takahisa  ; Akiniwa, Yoshiaki*; Yagi, Tsuyoshi*; Yamamoto, Masataka*

The railway carbody structure for commuter and suburban services in Japan is often made of austenitic stainless steel, which is used as the thin metal sheets by cold rolling. To observe a strain distribution around weld zone, where is the critical area of the body structure strength, the strain scanning method by using high-energy synchrotron radiation was applied to the strain measurement of austenitic stainless steel. Two welded specimens at lapped splice were measured, one is 1.5 mm thick by spot welding joint, and another is 2.0 mm thick by laser welding joint. The sizes of gauge volume were a width of 2 or 3 mm and a height of 0.15 mm in this measurement. This measurement provides the strain distribution, which includes both residual strain and strain under loading. The result by this measurement shows strain distribution in the weld zone successfully. In addition, the different tendency to the distribution from residual strain and strain under loading made be clear.