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.

Optimization of Hydroforming Process for Deep Drawing of AA7075 Using Finite Element Simulation and Response Surface Methodology

Abstract: Aluminum 7075 is a functional aerospace alloy that has high strength and low formability during room temperature deep drawing. Therefore, to avoid warm forming process and relative difficulties, careful control in the process design is needed to enhance quality of drawn part and improve die life. In the present work, an attempt was made to experimentally and numerically study the effect of hydrodynamic deep drawing process such as die geometry and fluid pressure on thinning ratio and punch force. Statistical analysis based on response surface methodology was carried out to correlate empirical relationship between die corner radius, punch corner radius and die fluid pressure as process factors and maximum thinning ratio and punch force as responses. Sensitivity analysis was also performed to find out the factor having greatest impact on aforementioned responses. Further, optimization was carried out by using desirability approach to find out optimal parameter setting to attain minimum thinning and forming force simultaneously. Results indicated that punch and die corner radius followed by fluid had significant effect on the process quality characteristics. Moreover, setting of 9.3 mm punch corner radius, 2 mm die corner radius and 26 MPa fluid pressure resulted in 71% desirability incorporating 31% thinning and 175 MPa punch force. The obtained optimal results were then verified through both FE simulation and confirmatory experiment.

Study on the mechanism and the suppression method of wrinkling in side wall using hydroforming of the fairing

Abstract: Study on the mechanism and the suppression method of wrinkling in side wall of the aluminum alloy fairing using hydroforming, and the side wall is suspended curved surface shell. The wrinkling problem of side wall is analyzed on conical parts by combined with the theoretical calculation, finite element method (FEM) and experimental verification. To reduce the complexity of forming, the suspended surface is divided into several parts, and they are analyzed by theoretical calculation and FEM to discuss the rationality of the two schemes, which is proposed. And the critical strain is the wrinkling evaluation index, the size, and the amplitude of the critical strain can be the qualitative analysis of wrinkling trend. The suspended surface is divided into two regions, the trend of material flow is studied in the geometric view, and predicts the possibility of the wrinkling. The wrinkling of the suspended surface is not only related with the geometry of the part, but also be related with the loading path. It is controlled the qualitative analysis of wrinkling by adjusting the parameters about loading path, and get the relationship of pressure and punch stroke when the wrinkle happens. The qualified parts can be obtained in each process through optimized the parameters in the process of loading.

Improvement of Formability in Tube Hydroforming by Reduction of Friction with a High Viscous Fluid Flow

Abstract: Tube hydroforming is an advanced technology for the manufacturing of lightweight components with complex shape The forming results can be usually improved if axial feeding at the tube ends is enabled For very long parts, however, due to the high friction forces acting at high pressure in the feeding zone between tube and die, no material movement towards the expansion area occurs The tube is only upset in the feeding zone, no compressive stresses take place in the expansion area and the forming results are not satisfactory This can be avoided by eliminating friction and by inducing additional tangential stresses in axial direction on the tube surface of the feeding area This paper presents the investigations performed in this direction by using a high viscous fluid flowing along the internal and external surface of the tube The flow helps to reduce the friction force and allows the sliding between the tube and the tool surface Experimental tests of tube upsetting under pressure will show the effects of the medium flow on the thickening of the tube wall Not only increased sliding and homogeneous thickening will be obtained, but even an increase of the wall thickness in the area close to the expansion zone will be shown This effect is even stronger when the yield stress in the expansion zone is reduced by means of a previous local heat treatment