Abstract: A front end of a left member having a first plate thickness, and a left end of a lateral member having a third plate thickness are welded together while defining a first weld line, and a front end of a right member having a second plate thickness and a right end of the lateral member are welded together while defining a second weld line. The first plate thickness and the second plate thickness are thinner than the third plate thickness, and a support bracket that supports an auxiliary equipment is fitted to the lateral member. The first weld line and the second weld line are respectively positioned outer side of the vehicle body with respect to a fitted position of the support bracket, so as not to overlap on the fitted position in the lateral member where the support bracket is fitted to the lateral member.

Abstract: Non-destructive testing system performs accurate testing as to whether lamination joining portion of different metal materials is in strong joining state by secure metal joining. The system sets a lamination joining portion of different metal materials of a work to a certain position and angle. Laser light in certain waveform is applied to lamination joining portion surface to capture images by infrared camera, and data processing device obtains infrared images. Based on infrared images, Fourier transform is performed on each pixel of infrared images, and phase image is created by console device. Based on created phase image, effectiveness/defectiveness of joining is determined. In this non-destructive testing, whether reflection by vertical wall in vicinity is significant is determined, based on intensity of infrared images obtained immediately after irradiation with laser and angle between laser light optical axis and testing part surface is finely adjusted to obtain infrared images with less noise.