Hydroforming is a relatively new metal forming process with many advantages over traditional cold forming processes including the ability to create more complicated components with fewer operations. For certain geometries, hydroforming technology permits the creation of parts that are lighter weight, have stiffer properties, are cheaper to produce and can be manufactured from fewer blanks which produces less material waste. This paper provides a detailed survey of the hydroforming literature of both established and emerging processes in a single taxonomy. Recently reported innovations in hydroforming processes (which are incorporated in the taxonomy) are also detailed and classified in terms of “technology readiness level”. The paper concludes with a discussion on the future of hydroforming including the current state of the art techniques, the research directions, and the process advantages to make predictions about emerging hydroforming technologies.

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A state of the art review of hydroforming technology: its applications, research areas, history and future in manufacturing

In order to meet the requirements of high reliability, long-lifetime and lightweight in a new generation of aerospace, aircraft, high-speed train, and new-energy power equipment, integrated components are urgently needed to replace traditional multi-piece, welded components. The applications of integrated components involve in a series of large-size, complex-shaped, high-performance components made of difficult-to-deform materials, which present a huge challenge for forming ultra-large size integrated components. In this paper, the developments and perspectives of several extreme forming technologies were reviewed, including the sheet hydroforming of ultra-large curved components, die-less hydroforming of ellipsoidal shells, radial-axial ring rolling of rings, in situ manufacturing process of flanges, and local isothermal forging of titanium alloy components. The principle and processes for controlling deformation were briefly illustrated. The forming of typical ultra-large size integrated components and industrial applications were introduced, such as the high strength aluminum alloy, 3 m in diameter, integrated tank dome first formed by using a sheet blank with a same thickness as the final component, and a 16 m diameter, integrated steel ring rolled by using a single billet. The trends for extreme forming of ultra-large size integrated components were also discussed with a goal of providing ideas and fundamental guidance for further development of new forming process for extreme-size integrated components in the future.

https://iopscience.iop.org/article/10.1088/2631-7990/ab22a9/pdf

Developments and perspectives on the precision forming processes for ultra-large size integrated components

Deformation analysis of double-sided tube hydroforming in square-section die

Analytical model for planar tube hydroforming: Prediction of formed shape, corner fill, wall thinning, and forming pressure

Analysis of thickness distribution of square-sectional hydroformed parts

Analysis of thinning at the transition corner in tube hydroforming

The loading path is crucial to the quality of forming parts in the process of tube hydroforming, and thus the design and optimization of loading path is an important issue for tube hydroforming. Wrinkling is a catastrophic defect for thin-walled tube hydroforming. In order to avoid wrinkling, an adaptive simulation approach integrated with a fuzzy control algorithm is used to optimize the loading path of hydroforming a T-shaped tube. The tubular material used is stainless steel and has an outer diameter of 103 mm and the wall thickness of 1.5 mm. The controlled variables are the axial feeding, the counterpunch displacement, and the internal pressure. A code is developed to make the optimization automatically, which works together with LS-DYNA. Six evaluation functions are adopted for identifying geometrical shape and quality of T-shape. Failure indicators obtained from the simulation results are used as the input of the fuzzy control, and then process parameters are adjusted according to the expert experiences in the fuzzy controller. In this way, a reasonable loading path for producing a sound T-shape is obtained, and also a T-shaped product is successfully hydroformed by experiment. The result shows that the fuzzy control algorithm can provide an adequately reliable loading path for hydroforming T-shaped tubes.

Optimization of loading path in hydroforming T-shape using fuzzy control algorithm

Based on the sidewall wrinkling phenomena in hydroforming of thin-walled Tee-joint, an analytical model for tube wrinkling under double side constraints was proposed to calculate the critical wrinkling stress. The effects of stress ratio, diameter-to-thickness ratio and tube material properties on critical condition of sidewall wrinkling were investigated. It is found that the middle of the main tube side wall is the most dangerous position for wrinkling within hydroforming of thin-walled Tee-joint. At a certain internal pressure, the critical wrinkling stress increases with increasing of ratio of hoop stress to axial stress and material strength coefficients, but decreases with increasing of work-hardening exponent and ratio of diameter to thickness. Through the analytical model combining FEM simulation, the critical wrinkling loading path according to the relation between axial feeding and internal pressure was obtained. Experimental results validates that wrinkle can be avoided if the pressure is above the critical wrinkling loading path, otherwise, wrinkle occurs. It is also verified that the analytical model of critical wrinkling stress is reasonable for the thin-walled Tee-joint hydroforming process.

B.G. Teng

Papers

Analysis of thinning at the transition corner in tube hydroforming

Optimization of loading path in hydroforming T-shape using fuzzy control algorithm

Analysis on critical conditions of sidewall wrinkling for hydroforming of thin-walled Tee-joint

Progress in shell hydroforming

Research on hydro-forming of combined ellipsoidal shells with two axis length ratios