Control of Defects in Deep Drawing of Tailor-welded Blanks for Complex Shape Automotive Panel

With the development of lightweight vehicles, tailor welded blanks (TWBs) are increasingly used in the automotive industry. Splitting and wrinkling are the main defects during the deep drawing of TWBs. A new method to control the forming defects was introduced in the forming process of TWBs in this study. The microstructure and mechanical properties of TWBs were characterized through metallography and tensile tests. Finite element modelling of an automobile rear door inner panel made of TWBs was built to analyse deep drawing. Edge cutting and notch cut were introduced in the drawing to deal with forming defects and reduce the number of stamping tools. The minimum distance between the material draw-in and trimming lines, thinning index and thickening index were defined as the measurable index to analyse the numerical results. Orthogonal experiment, numerical simulation and multiobjective experiment were utilised to optimize the forming parameters. The proposed method and optimised parameters were verified through experiments. The experimental results are basically consistent with the numerical simulation. Results demonstrate that the proposed method can provide some guidance for controlling the defects in deep drawing of TWBs for complex shape automotive panel.

A Concurrent Design Exploration Method for Realizing Networked Manufacturing Systems

Multistage manufacturing processes (MMPs) are networked manufacturing systems consisting of multiple operational stations that have characteristics of mechanical and control systems. Common challenges in the design of MMPs are the selection of sensors and tools as this not only affects the dimensional quality of the finished product, but also influences the computational complexity in representing and analyzing the problem. Imprecise or incomplete information results in uncertainty in the models used to represent the MMP and limit the use of traditional design approaches. In this paper, an exploration method for the concurrent design (CDEM) of MMPs under uncertainty is presented wherein the attributes of tools and sensors are treated as design variables, thereby allowing flexibility in a design process. The proposed method is illustrated using an example of automotive panel stamping process. Our focus in this paper is on the method rather than the results per se.