Laser welding method, laser-welded joint, outside sheathing panel, and body structure for rolling stock

A side construction has an outside sheathing and outside sheathing reinforcement members A and B joined to the outside sheathing interiorly of the outside sheathing . The reinforcement member A (B) is shaped like a hat in section. The reinforcement members A provided in the vicinity of a window opening portion have a laser welding spacing L of 80 mm and each have a hat width of 50 mm, while the reinforcement members B provided on other part have a laser welding spacing L of 100 mm and each have a hat width of 70 mm. The reinforcement members A and B each have a height of 25 mm.