Showing papers on "Hydroforming published in 2021"

Hydroforming process of complex T-shaped tubular parts of nickel-based superalloy

Abstract: Nickel-based superalloy thin-walled components have been used in aerospace equipments requiring high reliability and durability at high-temperature condition. To overcome the problem of severe thinning occurs in conventional one-step hydroforming, this paper proposes an innovative multi-step hydroforming process for manufacturing complex T-shaped tubular parts of nickel-based superalloy. The appropriate process parameters in every step for preventing undesirable wrinkling and splitting defects, including internal pressure, axial feeding length, axial feeding ratio, and retreating displacement of middle punch, have been determined through a detailed numerical simulation investigation. The results show that manufacturing of a GH4169 T-shaped tubular part with expanded diameter can be successfully implemented using a four-step hydroforming. Moreover, the four-step hydroforming process, as well as the forming defects and the thickness distribution of several typical sections on the hydroformed GH4169 T-shaped tubular part, are all discussed. Finally, the complex GH4169 T-shaped tubular part with a thickness more than 3 mm can be obtained successfully after the top of the side branch is removed. These results provide insights for the manufacturing of T-shaped tubular part with expanded diameter, and contribute to the development of superalloy tube forming process at room temperature.

Latest Hydroforming Technology of Metallic Tubes and Sheets

Abstract: Hydroforming processes of metal tubes and sheets are being widely applied in manufacturing because of the increasing demand for lightweight parts in sectors such as the automobile, aerospace, and ship-building industries [...]

Investigation on deformation behavior of magnesium alloy sheet AZ31B in pulsating hydroforming

Abstract: Magnesium alloys have been known as the next generation material for lightweight body structures. Pulsating hydroforming is an effective method to improve magnesium alloy sheet forming performance,...

Determination of the forming limit of impact hydroforming by frictionless full zone hydraulic forming test

Abstract: It is impossible to obtain the forming limit curve (FLC) by full zone hydraulic forming test under quasi-static (QS) condition since the liquid will leak from the notches of the specimen once the pressure increases. In this study, a novel method is proposed to investigate the frictionless full zone hydraulic FLC of AA5A06 under high strain rate (HSR) condition based on the impact hydroforming technology (IHF). It is found that the FLC is increased significantly by IHF compared with the quasi-static rigid punch (QS-R) forming and the quasi-static hydraulic (QS-H) forming. Differentiating with the QS-H, the increase amounts of FLC at the biaxial tension zone and the tension-compression zone are notably different for IHF. Additionally, the theoretical calculations of FLC is conducted by using M-K model combining with Hill48 anisotropic yield criterion under QS and HSR conditions. The results calculated by the M-K model reasonably agree with the ones obtained from experimentation under QS and HSR condition, and a higher initial thickness ratio is assigned for HSR considering the neck postponing effect of inertia.

Manufacturing of a corrugated double-layered tube for the high-performance compact heat exchanger

Abstract: Compact heat exchangers are expected to be one of the solutions for advanced heat exchanger having light weight, minimum volume, and high performance to improve the uses of energy sources and contribute to sustainability. Conventional double-pipe heat exchangers allow poor heat transfer performance owing to the concentrically arranged simple cylindrical structure. Therefore, passive enhancement technique employing circumferentially corrugated double tubes has been characterized and manufactured in this study as one of the most realistic alternatives to enhance heat transfer performance. To fabricate double-layered tube with circumferentially corrugated pattern, the customized hydroforming process using corrugate forming bars was developed and experimentally implemented on the basis of the simulated bulge height, internal pressure, and contracted stroke at various forming bar diameters. The circumferential cross-sectional profiles were observed to estimate the soundness of the hydroformed corrugated tube, and the results provide a useful solution for manufacturing high-performance compact heat exchangers with enhanced reliability and applicability.

A comprehensive damage criterion in tube hydroforming

Abstract: In the present study, the Johnson-Cook damage model is proposed as a comprehensive damage criterion to predict all types of probable failures in tube hydroforming process. Also, the Johnson-Cook ma...

Effects of pressure, boundary conditions, and cutting reliefs on thermo-hydroforming of fiber-reinforced thermoplastic composite helmet based on numerical optimization:

Abstract: Compared with layup techniques, thermo-hydroforming is shown to be a viable process for mass production of thermoplastic composite structures due to its relatively rapid cycle time and low impact o...

An Analysis of Process Parameters in the Hydroforming of a Hemispherical Dome Made of Fiber Metal Laminate

Abstract: Even though fiber metal laminates (FMLs) were developed many years ago, existing forming approaches are not well qualified to produce intricate and small thin geometry. There are great difficulties in the deep drawing procedure, even for low forming depth. These difficulties are mainly related to the fiber layers limited elongation compared to the metals, and the process parameter selection during the deep drawing, which needs to be chosen very carefully. This research presents a numerical and experimental study on the influence of the hydroforming process parameters on FML hemispherical dome. The Aluminum 2024-T3 and prepreg glass fiber were used to produce the FML blanks. The parameters covered in this investigation were cavity pressure (CP), blank holder force (BHF), die entrance radius (DR), blank holder gap (BHG), and punch speed (PS). Taguchi’s design of experiments determined the effects of the input parameters on wrinkling and thinning. Results indicated that the BHG has the most significant impact on thinning and wrinkling. Optimization was conducted, and the optimum selected process parameter values were 80 kN for BHF, 15 MPa for CP, 8 mm for DR, 1.1 mm for BHG, and 30 mm/min for PS. Results revealed that FML cups formed by the optimized parameters could improve the utilization of the FMLs in mass production.

Yield criterion influence on the formability prediction of SS 304 by tensile tests and bulge tests during tube hydroforming process

Abstract: Finite element (FE) simulation of sheet/tube forming precision depends mainly on the accuracy of the yield surface shape used in mechanical modeling. The yield surface mainly depends on the number of input variables used to define the yield surface. The present paper's aim is to compare the constitutive models to fit the hardening laws. The accurate deformation behavior of the SS 304 tubes depends on the constitutive modeling of hardening behavior. Deformation data of the tubular samples were collected by conducting uniaxial tensile tests and tube bulge test. The best fitted constitutive hardening model was utilized on both Hills 1948 and Hills 1990 yield criteria and the accuracy of the simulations was predicted. Thickness and strain distributions, as well as the geometry of the bulged specimen, were taken as comparison parameters. Experimental validation was performed on all the available predicted data and was observed to be best for the Hills 1990 yield criteria.

Predictions of formability parameters in tube hydroforming process

Abstract: The objective of this study is to improve the bulging and minimize the thinning ratio to enhance manufacturing of components in Industries. Tube hydroforming is an advanced manufacturing technology used for making intricate and complex tubular parts which required less cycle time. This research focuses on hydroforming process, formability and process parameters design to replace the conventional tube bending, welding and cutting operations. The prediction of parameters is done by applying numerical and experimental approach. During experimentation the pressurized fluid is used to deform the tubes in a plastic deformation. In this study, two types of grade materials are used such as AISI304 and AISI409L of 57.15 mm external diameter with 1.5 mm thickness in the form of electric resistance welded tubes to measure stain path, thinning and bulge height. However, it is observed that the internal pressure and L/D ratio are effective parameters in both numerical analysis and experimentation. In axial feed condition, it is observed that 16.3% thinning in weld region and 44.6% thinning in base metal region, whereas, in fixed feed condition, it is observed that 7.7% thinning in weld region and 18.6%thinning in base metal region for L/D = 1 and L/D = 3 respectively. The numerical analysis with experimental results shows a very good match. It is seen that the axial feed leads to better formability with fixed feed condition because in axial feed condition material supplies towards the center of the bulge tube. The feasibility of the hydroforming process for manufacturing of AISI304 and AISI409L grade material as per the requirements of the industries is also checked. The maximum bulging is observed in L/D = 2 by comparing with the other ratios. This process can be effectively used for AISI304 grade material because the formability is better than AISI409L.

Residual contact pressure and elastic recovery of an assembled camshaft using tube hydroforming

Abstract: The assembled camshaft is a recently developed split assembly technology that enables the realization of lightweight cars and improves engine performance Residual shaft–cam contact pressure is affected by camshaft elastic recovery and affects connection quality This study investigated a cam with an isometric–trilateral profile for tube hydroforming with a hollow shaft via experiments and finite element analysis A novel, indirect residual contact pressure measurement method is herein proposed Hydraulic parameter effects on residual contact pressure and elastic recovery were analyzed using the theory of plastic mechanics For hydraulic pressure below 85 MPa, increasing hydraulic parameters increased residual contact pressure nearly linearly while decreasing elastic recovery

Numerical investigation of the effect of material properties on forming metal bellows

Abstract: Forming process of the metal bellows is very sensitive to the fluctuation of material parameters. In this state, revealing the influence of material parameters on deformation behaviors is important for desirable dimension and mechanical performance. In this paper, the effects of the material parameters of 316L stainless steel on the bellow hydroforming process are studied by finite element analysis and Taguchi method. The most important factor influencing the final shape of convolution of the metal bellows is found out. Two multi-linear regressions between the quality responses and the material parameters are extracted and evaluated by simulated and experimental results. Based on the regression equations, response surfaces of the quality characteristic and the reasonable factor region for required forming quality are obtained. Further, the relationship between the internal pressure and the material parameters is built to guarantee the shape of the bellows. The method is applied in the scenario when the material is changed to AISI 304 steel, and a satisfying prediction profile is achieved.

Numerical investigation of plastic flow and residual stresses generated in hydroformed tubes

Abstract: During tube hydroforming process, the friction conditions between the tube and the die have a great importance on the material plastic flow and the distribution of residual stresses of the final co...

Effects of material and process parameters on wrinkling of conical parts in modified hydroforming process

Abstract: Hydrodynamic deep drawing assisted by radial pressure with inward flowing liquid, proposed as a benchmark in the Shemet2017 conference, is selected to analyze the influence of the process parameters on wrinkling behavior. The radial pressure can reduce forming force and increase drawing ratio in hydrodynamic deep drawing, but at the same time can cause wrinkling. The wrinkling in the wall area of conical parts is a challenge because the sheet is not supported in this region. The side wall wrinkling of St13 and copper conical cups is investigated through numerical simulation and experimental measurements. After preliminary experimental validation, the FEM simulation was performed to explore the process parameters. The effects of radial and cavity pressures, sheet thickness, punch velocity, and friction coefficient on wrinkling were studied based on the developed FEM model and using a geometric method. Maximum wrinkling height was presented as a parameter for wrinkling investigation for conical parts. It was demonstrated that the severity of wrinkles predicted by the numerical model is influenced strongly by the process parameters. Finally, according to the obtained results, and by controlling the maximum wrinkling height parameter as a result of pressure change, a piece without wrinkling and rupture was properly formed.

Process analysis of biconvex tube hydroforming based on loading path optimization by response surface method

Abstract: Biconvex tube is prone to problems such as severe wall thickness reduction or wrinkling in hydroforming due to the big diameter-thickness ratio and large expansion ratio. In this paper, the segmented dies were employed to manufacture the biconvex tube, and the forming performance of the part under different loading paths was simulated by ABAQUS/Explicit software, then the corresponding results were obtained. The influence of loading path–related factors on the formability of the biconvex tube was analyzed by the response surface method. Based on the optimization evaluation criteria, the predicted loading path was determined to be linear loading, and the maximum axial feeding was 13 mm and the maximum internal pressure was 89 MPa.

Less-loading hydroforming process for large-size hollow components of aluminum alloy

Abstract: To overcome the problem of welding distortion on conventional multiple segment structures, and the problem of requiring large-scale forming equipment and severe thinning occurs in high-pressure hydroforming process, a novel less-loading hydroforming process is proposed for manufacturing large-size hollow components in this paper. The geometrical relationship of the tube blank during less-loading hydroforming process is firstly discussed. Then, experiment and numerical simulation are conducted to investigate the forming behavior of a large-size tubular component of aluminum alloy 5A06 with rectangular cross-section. It is found that the needed internal pressure, die closing force, and axial force for the less-loading hydroforming are significantly reduced, which are about 1/22, 1/8 and 1/28 of those required in high-pressure hydroforming, respectively. During the less-loading hydroforming process, the tube blank is firstly deformed by bending to fill the die corners, and then deformed by circumferential compression. Moreover, the compression deformation characteristics make the thickness increase. However, a too large circumferential compression and/or an insufficient supporting pressure will cause a wrinkle defect. These results provide insights for less-loading and approaching uniform manufacturing of large-size hollow components.

Multi-objective optimisation of tube hydroforming process on IF steel using Taguchi-based principal component analysis

Abstract: Tube hydroforming is one of the eccentric metal shaping procedures, especially utilised as a part of the automotive industry. This process has accentuated much consideration inferable from its diversified applications. To emphasise, aerospace and automotive industries depend much upon this procedure. Earlier most of the researchers worked on the material characterisation and the process parametric impacts of tube hydroforming process. However, very few have attempted on the Multi-objective optimisation of the critical process parameters. In this work, commercial finite element code PAM-STAMP 2G is utilised to do the simulations in view of L27 orthogonal array. Hence a multi-objective optimisation was studied that simultaneously maximises the bulge ratio and minimises the thinning ratio by Taguchi-based principal component analysis (PCA), which is novelty of this work. The present work aims at exploring the impact of geometrical, process and material parameters on aforementioned responses using analysis of variance (ANOVA).

Investigation on formability improvement in laser shock hydroforming

Abstract: Laser shock hydroforming is a novel microforming method that adopts laser energy as the driving force and liquid as the medium to transmit pressure. The method combines the advantages of laser shock forming and micro hydroforming. Previous research has demonstrated that this method can deform thin sheets into complex shapes at high strain rates. We know that the formability of materials is improved at high strain rates, but experimental analysis on this method alone cannot examine the deformation process. Therefore, this study first conducted free- and die-forming experiments of laser shock hydroforming to characterise the features of the deformation process and understand the factors that may contribute formability enhancement. Experimental results were discussed to uncover the formability of thin sheets under different conditions, including the laser energy and the effect of the die. Then, a numerical model was established considering fluid–solid interaction. The deformation process, sheet velocity, contact stress and strain rate were investigated through numerical means, and these indicators explain the mechanism of formability improvement in this method. Furthermore, the numerical results indicate a positive phenomenon—pressure equalisation—which might be due to the reflection of pressure off the rigid side wall of the liquid chamber.

Optimization of Process Parameters during Hydroforming of Tank Bottom using NSGA-III Algorithm

Abstract: The hydroforming technology can realize overall forming of large storage tank’s bottom, but the quality is affected by many technological parameters. In view of wrinkling and cracking defects of integral storage tank’s bottom in hydroforming, a multi-objective optimization model is established for process parameters include pre-expansion pressure, hydraulic pressure, blank holder force and fillet radius of blank holder. Based on finite element simulation, the surrogate model between process parameters and quality criteria is established using Kriging technique. NSGA-III is used to determine optimal process parameters when storage tank’s bottom reaches targets include minimum wall thickness variations, minimum fracture trend, minimum flange wrinkle and minimum wrinkle trend. Compared with Particle swarm optimization (PSO) algorithm, NSGA-III algorithm is more suitable to solve this optimization problem. The validity of this method and accuracy of the results are verified by simulation experiments.

An Analytic Solution for an Expanding/Contracting Strain-Hardening Viscoplastic Hollow Cylinder at Large Strains and Its Application to Tube Hydroforming Design

Abstract: This paper presents a semi-analytic rigid/plastic solution for the expansion/contraction of a hollow cylinder at large strains. The constitutive equations comprise the yield criterion and its associated flow rule. The yield criterion is pressure-independent. The yield stress depends on the equivalent strain rate and the equivalent strain. No restriction is imposed on this dependence. The solution is facilitated using the equivalent strain rate as an independent variable instead of the polar radius. As a result, it reduces to ordinary integrals. In the course of deriving the solution above, the transformation between Eulerian and Lagrangian coordinates is used. A numerical example illustrates the solution for a material model available in the literature. A practical aspect of the solution is that it readily applies to the preliminary design of tube hydroforming processes.

Warm Hydroforming Process under Non-Uniform Temperature Field for Magnesium Alloy Tubes

Abstract: The warm tube hydroforming (WTHF) process of lightweight materials such as magnesium alloy contributes to a remarkable weight reduction. The success of the WTHF process strongly depends on the loading path with internal pressure and axial feeding and other process variables including temperature distribution. Optimization of these process parameters in this special forming technique is a great issue to be resolved. In this study, the optimization of the symmetrical temperature distribution and process loading path for the warm T-shape forming of magnesium alloy AZ31B tube was carried out by finite element (FE) analysis using a fuzzy model. As a result, a satisfactory good agreement of the wall thickness distribution of the samples formed under the optimum loading path condition can be obtained between the FE analysis result and the experimental result. Based on the validity validation of FE analysis model, the optimization method was applied to other materials and forming shapes, and applicability was discussed.