Simulation and Analysis of Forming Process with an Elastic Bed and Investigation of Damage Mechanics

Rubber-pad forming process is a versatile metal fabrication process used in commercial aerospace, automotive and military applications. This process is well suited for prototyping and production of small quantities of sheet metal parts. Different techniques of rubber-pad forming processes for sheet and tube forming are introduced and advantages and disadvantages of the process are discussed in detail. Rubber pad forming (RPF) is a metalworking process where sheet metal is pressed between a die and a rubber block, made of polyurethane. Under pressure, the rubber and sheet metal are driven into the die and conform to its shape, forming the part. The rubber pads can have a general-purpose shape, like a membrane. Alternatively, they can be machined in the shape of die or punch. Rubber pad forming has been used in production lines for many years. Up to ۶۰% of all sheet metal parts in the aerospace industry are fabricated using this process. The most relevant applications are indeed in the aerospace field. It is frequently used in prototyping shops and for the production of kitchenware. A three-dimensional finite element simulation, based on the rigid–plastic model for the analysis and design of rubber pad-forming process was developed. The hydraulic pressure force is applied to the normal direction of the blank work piece by integrating the pressure with respect to each element’s surface area. The predicted simulation results provide information on the actual design. This numerical approach to the rubber pad-forming process will be useful to the development and application for a wide range of automobile structural components. In this paper, ۳D model of rubber pad-forming has been simulated by finite element method. Two damage model, coupled with von Mises plastic criterion, have been applied to predict where and when onset of ductile and shear rupture occurs. Also, ۳D model of rubber pad-forming has been simulated to study the Deformation of blank, Distribution of stress contours, Contour of equivalent plastic strain in process. All studies presented in this paper have been carried out on aluminum alloy.

Keywords:

Rubber Pad-Forming , Numerical Investigation , NBR , Ductile Fracture Criteria , Shear Fracture Criteria , Aluminum Alloy