Multi-Objective Optimization of the Hydroforming Process Considering Different Plastic Yield Criteria

2015 ◽  
Vol 651-653 ◽  
pp. 1394-1399 ◽  
Author(s):  
Vito Piglionico ◽  
Antonio Piccininni ◽  
Gianfranco Palumbo ◽  
Luigi Tricarico
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Forming Limit ◽  
Al Alloy ◽  
Algorithm Optimization ◽  
Explicit Finite Element ◽  
Yield Criteria ◽  
Multi Objective ◽  
Hydroforming Process ◽  
Warm Hydroforming

The present work aims at determining the optimal working conditions for the manufacturing of the AA6061-T6 Al alloy by the hydroforming process. As case study a stepped geometry was used. A numerical model was created using the commercial explicit Finite Element code LS-DYNA. The plastic behaviour of the investigated alloy was modelled implementing experimental data (flow stress curves, Lankford coefficients and Forming Limit Curves) and using two different yield criteria: an anisotropic one (Barlat ‘89) and the conventional isotropic one (Von Mises). Finite Element models were tuned using experimental data from warm hydroforming tests: comparing both the sheet thinning and the die cavity filling, quite different friction conditions had to be supposed for obtaining a good fitting with both the yield criteria.Finite Element models were finally used for evaluating the working range of the hydroforming process: results from a CCD simulation plan were imported within an integration platform (modeFRONTIER) to evaluate the optimal hydroforming conditions based on a multi-objective genetic algorithm optimization. Quite different results in terms of optimization and working range were obtained when adopting different yield criteria.

An Experimental and Numerical Study to Analysis and Design of Sheet Hydroforming Process for an Automobile Fender Shell

2006 ◽  
Author(s):  
Mohammad Habibi Parsa ◽  
Payam Darbandi
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Fluid Pressure ◽  
Finite Element Program ◽  
New Approach ◽  
Explicit Finite Element ◽  
Sheet Hydroforming ◽  
Analysis And Design ◽  
Hydroforming Process ◽  
Element Program

A new approach for manufacturing of shell fender is proposed and has been examined numerically and experimentally. The new suggested method is based on sheet hydroforming process, which has a lot of advantages over conventional deep drawing process. After defining the shape of initial blank using an inverse finite element program, numerical evaluation of the proposed sheet hydroforming process for production of shell fender has been carried out using an explicit finite element code considering fluid pressure, boundary conditions and tools. Then experimental evaluation has been carried out using down sized specimen and the results have been compared with results of previous simulations. It has been shown that there are similar trends between finite element and experimental results.

Study on the Finite Element Numerical Simulation of Automobile Crossbeam Stamping Forming

2011 ◽  
Vol 55-57 ◽  
pp. 2104-2108
Author(s):  
Xiao Chun Ma ◽  
Wei Bing Shen ◽  
Yi Qiang Zhuang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Optimal Parameter ◽  
Thickness Distribution ◽  
Metal Flow ◽  
Forming Limit Diagram ◽  
Design Parameters ◽  
Forming Limit ◽  
Explicit Finite Element ◽  
Finite Element Numerical Simulation

This paper is concerned with the quantitative effect of design parameters on the stamping process of automobile crossbeam. The considered parameters in this paper are the friction coefficient, the die fillet radius and the blank holding force, which greatly affect the metal flow during stamping. Based on the finite element numerical simulation, the stamping shaped process of the automobile crossbeam is numerical simulated with the explicit finite element method with various parameters by dint of Dynaform software. According to the simulation results, the forming limit diagram(FLD) and the wall thickness distribution of cloud on the stamping processes are technologically analyzed, the reasons and control methods of wrinkling are also pointed out, and then the optimal parameter combination of the automobile crossbeam is obtained by orthogonal experiments. It is noted that the parametric study of design parameters such as µ , BHF and RD are very important in the process design of the complicated member.

scholarly journals Effects of the roller feed ratio on wrinkling failure in conventional spinning of a cylindrical cup

2011 ◽  
Vol 225 (11) ◽  
pp. 1991-2006 ◽  
Author(s):  
L Wang ◽  
H Long ◽  
D Ashley ◽  
M Roberts ◽  
P White
Keyword(s):  
Finite Element ◽  
Simulation Models ◽  
Feed Ratio ◽  
Forming Limit ◽  
Explicit Finite Element ◽  
Shell Elements ◽  
Computational Performance ◽  
Spinning Process ◽  
Conventional Spinning ◽  
Cylindrical Cup

In this study, wrinkling failure in conventional spinning of a cylindrical cup has been investigated by using both finite element (FE) analysis and experimental methods. FE simulation models of a spinning experiment have been developed using the explicit finite element solution method provided by the software Abaqus. The severity of wrinkles is quantified by calculating the standard deviation of the radial coordinates of element nodes on the edge of the workpiece obtained from the FE models. The results show that the severity of wrinkles tends to increase when increasing the roller feed ratio. A forming limit study for wrinkling has been carried out and shows that there is a feed ratio limit beyond which the wrinkling failure will take place. Provided that the feed ratio is kept below this limit, the wrinkling failure can be prevented. It is believed that high compressive tangential stresses in the local forming zone are the causes of the wrinkling failure. Furthermore, the computational performance of the solid and shell elements in simulating the spinning process are examined and the tool forces obtained from wrinkling and wrinkle-free models are compared. Finally, the effects of the feed ratio on variations of the wall thickness of the spun cylindrical cup are investigated.

Formability of Al6061 Extruded Tube in Warm Hydroforming

2007 ◽  
Vol 340-341 ◽  
pp. 599-604 ◽  
Author(s):  
Young Seon Lee ◽  
Jung Hwan Lee ◽  
M.Y. Lee ◽  
Young Hoon Moon ◽  
T. Ishikawa
Keyword(s):  
Heat Treatment ◽  
Fe Analysis ◽  
Forming Limit ◽  
Bulge Test ◽  
Forming Process ◽  
Treatment Conditions ◽  
Hydroforming Process ◽  
Forming Temperature ◽  
Warm Hydroforming ◽  
Full Annealing

Formability of tube in elevated temperature is essential data to design the warm hydroforming process parameters, such as tube diameter, forming temperature and die geometries. Since the quantitative data of forming limit can be used to predict the failure on forming process, formability data available on the FE analysis is one of the very important information for the optimum design. In this study, the effect of heat treatment conditions and deformation temperature on the formability was investigated for the warm hydroforming of Al6061 tube. Full annealing and T6-treatment are applied for the heat treatment of Al6061 tubes. To evaluate the hydroformability, uni-axial tensile test and bulge test were performed at temperature ranges between room temperature and 300oC. The measured flow stresses were used as input parameters for the simulation of warm hydroforming process. The damage value and strain variation during hydroforming are analysed by FEM. A forming limit based on the ductile fracture criteria has been proposed by combining the results of experimental and FE analysis for the estimation of formability and optimization of warm hydroforming process.

Application of the Warm Hydroforming Process to the Manufacturing of Pre-Aged 6xxx Series Components Using a Numerical/Experimental Approach

2014 ◽  
Vol 622-623 ◽  
pp. 701-708 ◽  
Author(s):  
G. Palumbo ◽  
Antonio Piccininni ◽  
Pasquale Guglielmi ◽  
Donato Sorgente ◽  
Leonardo Daniele Scintilla ◽  
...  
Keyword(s):  
Cycle Time ◽  
Experimental Approach ◽  
Response Surfaces ◽  
Forming Limit ◽  
Bursting Pressure ◽  
Process Conditions ◽  
Al Alloy ◽  
Fe Model ◽  
Warm Hydroforming ◽  
6Xxx Series

In this work the Warm Hydroforming (WHF) process for the production of a 6xxx series Al alloy component has been investigated using a numerical/experimental approach: both experimental and numerical hydroforming tests were carried out using the alloy AC170PX, a pre aged (T4 condition) Al alloy often adopted for automotive applications. In order to evaluate both the mechanical and strain behaviour of the material, tensile tests were carried out at different temperature and strain rate levels using the Gleeble system 3180, keeping also into account the ageing effect; in addition, formability (Nakazima) tests in warm conditions were performed by means of a specific equipment and the Forming Limit Curves at different temperature levels were evaluated according to the ISO standard 12004-2. Hydroforming experiments were carried out using a prototypal press machine specifically designed for WHF and SuperPlastic Forming tests. Such tests, scheduled by a DoE approach, were aimed at investigating the suitability of using the investigated Al alloy in the WHF process: attention was thus focused on those parameters mainly affecting the aging phenomenon (temperature, heating time and cycle time). In order to overcome the actual physical limitation of the hydroforming facilities, a Finite Element (FE) model of the WHF process was also created implementing experimental data (flow stress curves and FLCs) and tuned using data from preliminary WHF tests. In particular, after setting the Coefficient Of Friction (COF) according to temperature and verifying the robustness of numerical simulations, the FE model was used for investigating: (i) the influence of the Blank Holder Force (neglected in the experimental campaign); (ii) the adoption of quite smaller values of the parameter cycle time (being the aim to determine higher strain rates in the material). Through the definition of proper response variables (Flatness, Bursting Pressure and Thickness Ratio) both experimental and numerical results were analyzed by means of polynomial Response Surfaces in order to evaluate the optimal process conditions.

scholarly journals A Virtual Testing Strategy to Determine Macroscopic Properties of Elasto-Plastic Heterogeneous Composite Materials

2021 ◽  
Author(s):  
◽  
Mahshid Ranjbarestalkhjani
Keyword(s):  
Finite Element ◽  
Composite Materials ◽  
Three Dimensional ◽  
Analytical Models ◽  
Testing Strategy ◽  
Virtual Testing ◽  
Explicit Finite Element ◽  
Yield Criteria ◽  
Representative Volume ◽  
Wide Range

The objective of this work is to determine an e˙ective yield criteria for porous pressure sensitive solids and investigate the anisotropic yield behavior by employing a virtual testing strategy. The work is concerned with the pressure sensitivity typically displayed by geometarials, such as sandstone and composite materials consisting of a series of parallel layers, such as sedimentary rock and underground salt.Virtual testing strategy is based on computational homogenization approach for the definition of the elasto-plastic transition. Representative volume elements (RVEs) containing single-centered and distributed ellipsoidal voids are analyzed using three-dimensional finite element models under both small and finite strains. Yield curves are obtained following a unified variational formulation, which provides bounds on the e˙ective material properties for a given choice of the Representative Volume Element (RVE).In order to estimate the e˙ective properties of porous solid, the constitutive behavior of the continuum matrix is assumed to follow the standard Drucker-Prager elasto-plastic model. The computationally generated e˙ective yield criteria are compared against the recently proposed analytical estimates for Drucker-Prager type solids and the SR4 constitutive model for soft rocks. The developed computational approach is applied to estimate the e˙ective properties of a realistic rock sample. To illustrate a wide range of potential engineering applications, the computationally e˙ective yield surface are also obtained under the explicit finite element method.Finally, based on the simulated yield stress point of composite materials, the pa-rameters for proposed analytical models are acquired with ellipse fit by Taubin’s method.

Investigation on Sheet Hydroforming Process of Titanium/Aluminum Clad Metal Housing

2010 ◽  
Author(s):  
Huang-Chi Tseng ◽  
Zong-Chun Wu ◽  
Chinghua Hung ◽  
Ming-Hu Lee
Keyword(s):  
Finite Element ◽  
High Surface ◽  
Dimensional Accuracy ◽  
Drawing Ratio ◽  
Explicit Finite Element ◽  
Sheet Hydroforming ◽  
High Surface Quality ◽  
Titanium Aluminum ◽  
Significant Process ◽  
Hydroforming Process

In this research, the sheet hydroforming process (SHF) was adopted to form a Ti/Al clad metal housing with complex shape. Nowadays, SHF has been widely accepted for the production of components characterized by high surface quality, precise dimensional accuracy together with high drawing ratio. For investigating the formability of the Ti/Al clad metal housing through SHF, the concept of virtual film were developed with explicit finite element method. First, the simulation model was verified by comparing the deformation of the blank obtained from experiments. Through finite element simulations, several significant process parameters such as holding force, tooling geometry, blank dimensions, single-stage (with pre-bulging effect) and multi-stages SHF were analyzed for improving formability of the Ti / Al clad metal housing during SHF.

Global Characterization of Failure Modes Under Impact Loading in Structural Components Made of Low Ductility Materials

2001 ◽  
Author(s):  
Shen Rong Wu ◽  
Xiaoming Chen ◽  
Weiran Hu
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Failure Process ◽  
Failure Criteria ◽  
Tensile Failure ◽  
Forming Limit ◽  
Structural Components ◽  
Explicit Finite Element ◽  
Finite Element Software ◽  
The Impact

Abstract This study reviews the impact failure modes of structural components made of materials with low ductility such as aluminum and magnesium. Tensile failure is observed at large stretch area or on the tension side of large bending deformation. Material breakage due to shear may also occur. There are several approaches to simulate the material failure process in explicit finite element software used for crashworthiness analysis. Evaluation of the effective applications of these material models is presented with a finite element simulation of bi-axial loading tests. The forming limit diagram is used to evaluate various failure criteria. Component crash simulations are presented to demonstrate the applications of failure criteria.

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