Hydroforming

About: Hydroforming is a research topic. Over the lifetime, 2796 publications have been published within this topic receiving 26293 citations. The topic is also known as: Bulge forming.

Two Dimensional Plane Strain Modeling of Tube Hydroforming

Abstract: The tube hydroforming process has been used in industry for several years to produce components such as exhaust manifolds. Recent advances in forming machines and machine control systems have allowed for the introduction and the implementation of the process to produce several automotive components, which were originally produced by the stamping process. Components such as side rails, engine cradles, space frames, and several others can be economically produced by tube hydroforming. The process involves forming a straight or a pre-bent tube into a die cavity using internal hydraulic pressure, which may be coupled with controlled axial feeding of the tube. One of the remaining challenges facing product and process engineers in designing hydroformed parts is the lack of an extensive knowledge base of the process. This includes a full understanding of the process mechanics and the effects of the material properties on the quality of the hydroformed product. This paper reports on the results of two dimensional plane strain finite element models of the tube hydroforming process, which were conducted using the commercial finite element code ABAQUS/Standard. The objective of the study is to examine the effects of material properties, die geometry, and frictional characteristics on the selection of the hydroforming process parameters. The paper discusses the effects of the strain-hardening exponent, friction coefficient at the die-workpiece interface, initial tube wall thickness, and die corner radii on the thickness distribution of the hydroformed tube.

A Novel Approach in Manufacturing Two-Stepped Tubes using a Multi-Stage Die in Tube Hydroforming Process

Abstract: Optimization of operating conditions is one of the most signicant issues concerning hydroforming the tubular components, including stepped tubes, conical tubes, box shape tubes, and etc. Obtaining a sharp corner without any defects such as thinning and rupturing is one of the main goals in the production of these components. In order to manufacture tubes with filled corners, it is common to increase the imposed pressure to the tubes. However, it may result in rupturing and thinning at the die corner radius, especially when it is too small. In this paper, a new multistage die has been proposed for producing two stepped tubes. Numerical modeling has been conducted using Abaqus/Explicit code. The results of simulation were afterwards checked against experiments in which it is shown that a better thickness distribution could be obtained employing the proposed die set. There is no thinning in the final workpiece, particularly at the copper tube corners. Moreover, it could be possible to produce two stepped tubes with complete filled corners. Finally, comparing to other well-established methods, a lower pressure profile is required and a better thickness distribution can be achieved.

Tube Hydroforming of Fuel Filler Pipes with Movable Dies

Abstract: Tube hydroforming is a relatively new approach to manufacture light weight metal structures. As the manufacturing technology became advanced, demands of lighter and stronger metal structures are also increasing. This research is to use tube hydroforming to expand the tube of a fuel filler for cars. The pipe material is JIS G3141. The product has a large expansion ratio at the edge of the pipe. Traditional tube hydroforming is difficult to achieve this large expansion ratio of a metal product. Tube hydroforming with movable dies is proposed to enhance the capacity of tube hydroforming technology. With movable die design, product with more uniform thickness can be obtained, and the forming pressure becomes lower than that needed in tube hydroforming without movable dies. A finite element code DEFORM-3D is used to analyze the plastic flow pattern of the tube. The loading paths of internal pressure, axial punches and movable dies for obtaining a sound product are determined by an adaptive simulation algorithm. The thickness distributions of the product for different loading paths are discussed.