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Plateau honing is being widely used in the production of cylinder bores to produce a surface to achieve the required functional performance. Characterizing plateau-honed surface irregularity into functional components is helpful for process control and functional analysis. The application of wavelet transform to characterize plateau-honed surface is presented. Difficulty exists in quantitatively determining the zooming level for functional characterizing the multi-process produced surfaces. In this paper, we utilize probability plot of bearing ratio curve, to quantify the zooming level of wavelet transform to obtain the functional components which related to different functional aspects from plateau honed surfaces. The effectiveness of this method is demonstrated.

In this paper, an adaptive strain methodology is developed for experimental strain measurement in sheet metal panels. The principle involves etching uniform small square grids on the panel, and measuring strains adaptively from deformations of large squares comprising of many smaller grids. The methodology uses FEA predicted strains as input and accounts for the experimental noise. The methodology overcomes the inability of the existing practice to simultaneously measure both low and high strain features, and in addition, saves considerable measurement time. The methodology is simple and can be easily integrated with automated strain measurement systems. The algorithm is distinguished for plane strain or radial symmetric panels whose strains vary along 1D (one dimension) and for other panel types whose strains vary along 2D (x and y). Correspondingly, the adaptive methodology is demonstrated for a hemispherical punch stretched and a box drawn panel.

In recent years the use of tailor-welded blanks (TWB) has grown significantly, but there still exists serious concern on the poor formability in the stamping of TWB, which is commonly considered to relate to the uncertainty in the weld line movement. This paper proposes a drawbead design methodology to achieve weld line movement control. Based on the properties, geometries and frictions of base-metals constituting the TWB, the magnitudes and ratio of drawbead restraining force (DBRF) between the two sides of the base metal sheets across the weld line, which is the function of drawbead depth, can be determined for minimizing the weld-line movement and enhancing TWB formability. In the case of 2D strip drawing with TWB, lower restraining force should be used in the side of thicker base metal to reduce weld line movement.

Resistance spot welding (RWS) guns driven by servomotors instead of pneumatic cylinders are called servo guns. They bring many new features to RWS process. In this study, the influences of servo guns on RSW process are systematically investigated based on comparative experiments. In addition, the costs of servo guns are also analyzed. The long-term applications of servo guns will be cost effective due to their technical features and savings on pneumatic systems although the acquisition cost of servo guns is high. Therefore, servo gun is an excellent alternative RSW machine for sheet metal assembly.