Papers by Keyword: Hydroforming

Abstract: The hydroforming process of differential gear box for automobile under axial compressive load and internal bulging pressure was simulated and the load paths were optimized. The hydroforming process is divided into two steps. The deformation under different load paths was investigated using dynamic explicit finite element method. The distribution of equivalent strain and thickness was investigated as well. The simulation results show that the forming path for the first step is optimal when internal pressure changes linearly from 37MPa to 65MPa with the axial displacement.

Abstract: In all areas of technology, the demand for high-quality, competitive and more valuable products is rising steadily. One approach to increase the value of manufactured products is the integration of electronic components in load carrying structures. These new products, which combine electrical and mechanical components synergistically, are called smart products. They consist of a passive structure and integrated electronics or smart materials. In addition to their mechanical properties they are also able to sense, to actuate or to transmit energy or data. The resulting product architecture requires both a mechanical and an electronic design in order to save subsequent assembly costs. Since further components are required to evaluate and control as well as to supply energy, all of those components need to be connected and integrated into the smart product. However, the main prerequisite for the marketability is the possibility of low-cost manufacturing and a robust mass production. Nowadays processes for the manufacturing of smart products do not fulfill the requirements for a sustainable mass production in a satisfying way as long as metallic structures are used. The authors deploy the forming technologies roll forming and sheet metal hydroforming to form sheets with applied flat electronics. Since the components are applied prior to the forming process, small and difficult to access installation spaces can be used effectively in the product architecture. The incremental bulk forming process rotary swaging is employed to integrate piezoceramics during the forming procedure without any additional joining elements. Challenges resulting from the chosen integrative manufacturing approach are the prevention of new kinds of failure modes and additional requirements for defined residual stress states. These challenges lead to extended process design requirements, which will be discussed in the paper in detail.

Abstract: The use of tube hydroforming in manufacturing is increasing in popularity, particularly in automotive applications where it offers numerous cost and well-recognized performance advantages over conventional stamping and welding processes. In this paper, the use of indirect Additive Tooling is explored in the creation of tool inserts to be used in the production of exhaust manifolds for the automotive industry. The principal focus of this research concerns the identification of operational issues arising from the exploitation of Additive Tooling, together with the suggestion of a number of techniques and solutions which may be applied to mitigate the problems inherent in the rapid manufacture of tube hydroforming tools.

Abstract: Due to the apparent advantages of tube hydroforming technology in reducing weight and energy consumption, and saving material and cost, it has been applied in the production of instrument panel beam. By constructing the FEM models of instrument panel beam, three numerical simulation schemes are designed according to the matching relationship between internal pressure load and axial feeding. Then the simulation results are given and compared with the experimental data. The simulation and experimental analysis indicate that the optimal matching relationship between internal pressure load and axial feeding influences hydroforming result of parts. It provides a theoretical reference for the design of hydroforming process and its die, and the setting of critical process parameters.

Abstract: After a brief introduction of state of art of hydraulic forming technology in China and abroad, the simulation experiment and finite element model of the directly forming and step-by-step forming are designed. According to the different characteristics of forming and spring back, the simulation analysis are performed through dynamic display algorithm and statistic implicit algorithm, and analyze the influence on tube thickness, spring back amount and the final residual stress of two different manufacturing processes which is compared with the experimental result. The comparison result can provide some theoretical reference for dashboard beam hydraulic forming process design, process parameter setting and mold design.

Abstract: The procing craft which make cross pipe by hydroforming is recommend. It created finite element model by DYNAFORM and simulated the process of hydroforming four-way tube. Forming result and influencing factor of different loading path is compared and analyzed. As a result, loading path has a great impact on the forming quality of four-way tube.

Abstract: Rear sub-frame is one of the important parts of automobile chassis. Tube hydroforming (THF) is a kind of the advanced manufacturing technology to produce the sub-frame. The success of a THF process is highly dependent on the loading paths (axial feed versus pressure) used. The uniform design method combined with the response surface method was used to optimize the loading path in this paper. The results obtained by numerical simulation demonstrated that product quality is good in the optimized loading path.

Abstract: Surface roughness was studied in the tube hydroforming process, considering the quality of the material and the coefficient of friction between the work piece and die. Other researchers have studied the surface roughness to the front of an aluminum pipe [. The aim of this work was to analyze changes in a copper pipe roughness occurred after hydroforming process with fluid. Effects of changing roughness were studied, following the deformation of the material in the work area and roughness changes occurring in the material flow. After achieving hydroforming process, the surface roughness was measured by electron microscopy SEM in different areas of the hydro formed tube. After hydroforming process, an increase of surface roughness in connection areas of the mold to the curvature and the transverse direction of the pipe.

Abstract: The counterpunch is usually used to control the protrusion height and also to control the evolution of thickness and avoid over thinning in T-shape or Y-shape hydroforming. In this study, the process of hydroforming a Y-shape is conducted by experiments, in which tubular material used is stainless steel and has an outer diameter of 42mm. Three kinds of counterpunches with end angle of 70, 80 and 90-degree are used to investigate its influence on wall-thinning and the height of the protrusion. The results show that the minimum wall-thinning can be obtained with an end angle of 70-degree, while a higher effective protrusion height can be formed with the increase of end angle.

Abstract: Based on the analysis of now available evaluation indexes to estimate the formability of Variable cross-section Y-shaped tube hydroforming, an aggregative indicator is proposed. The effect of load path on the formability of Variable cross-section Y-shaped tube is discussed by FEM simulation, and validity of the evaluation index and simulations are proved by experiment. Results show that with the broken line load path of 0-30-30-40, the value of aggregative indicator is the greatest and the formability is the best. The optional parameters are testified by experiment and the results are in agreement with the FEM simulation results.