scholarly journals Finite Element Analysis of Size Effect for Forming-Limit Curves

2020 ◽  
Vol 3 (2) ◽  
pp. 65-69
Author(s):  
Viktor Gál
Keyword(s):  
Finite Element ◽  
Size Effect ◽  
Forming Limit Diagram ◽  
Standard Test ◽  
Forming Limit ◽  
New Materials ◽  
Element Analysis ◽  
Test Pieces ◽  
The Difference ◽  
Forming Limit Curves

AbstractNowadays, finite element (FE) methods are widely used for the analysis of Body in White parts production. An FE software applies the forming-limit diagram to predict the failure of the sheet metal. There are many new materials for weight reduction; for these new materials, the determination of forming-limit curves (FLC) is important to studying formability issues. There are some cases where the available material for the measurements is not enough or due to some specific measurement parameter, the standard test specimen cannot be used. In these cases, the geometry of the test pieces and the testing equipment should be reduced. In this paper, the material card for DC05 (1.0312) steel was determined based on a tensile test and the Nakajima test. With the material card, simulations were performed to investigate the size effect of the hemispherical punch used for Nakajima forming method. Based on the simulations, the difference between the FLC-s (determined with different equipment) was found to be negligible.

Research on Finite Element Simulation and Test of Two-Pass Deep Drawing Forming for Conical Parts

2013 ◽  
Vol 652-654 ◽  
pp. 1966-1970
Author(s):  
Zhi Ren Han ◽  
Ze Bing Yuan
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Deep Drawing ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Element Analysis ◽  
Element Simulation ◽  
The Finite Element Analysis ◽  
Deep Drawing Test ◽  
As Stress

This paper is focus on two-Pass Deep Drawing Forming of conical axisymmetric parts, study on the finite element simulation and test of multi-Pass deep drawing part. It carry on the finite element analysis and calculation using the ANSYS/LS-DYNA software platform, analyzing the simulation results such as stress , strain distribution and formability by post-processing LSPOST software. It was done multi-Pass deep drawing test using a set of combined type mould. Based on the multi-Pass forming test by using a set of combined type mould, comparison of simulation and test data can be obtained through the forming limit diagram. The result of simulation and test is basically the same and both reflect the formability.

scholarly journals PADDLE SHAPE OPTIMIZATION FOR HOLE-FLANGING BY PADDLE FORMING THROUGH THE USE OF A PREDEFINED STRAIN PATH IN FINITE ELEMENT ANALYSIS

2019 ◽  
Vol 19 (2) ◽  
pp. 83-98 ◽  
Author(s):  
Lemopi Isidore BESONG ◽  
Johannes BUHL ◽  
Markus BAMBACH
Keyword(s):  
Finite Element ◽  
Strain Path ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Element Analysis ◽  
High Speeds ◽  
The Right ◽  
Hole Flanging ◽  
Bulge Formation ◽  
Principal Strains

This research investigates a novel hole-flanging process by paddle forming through the use of finite element (FE) simulations. Paddles of different shapes rotating at high speeds were used to deform clamped sheets with pre-drilled holes at their centers. The results of the simulations show that the paddle shape determines the geometry and principal strains of the formed flanges. A convex-shaped paddle forms flanges with predominant strains in the left quadrant of the forming limit diagram (FLD). However, the convex paddle promotes unwanted bulge formation at the clamped end of the flange. A concave paddle forms flanges with no bulge but the principal strains of elements in the middle section of the flange are in the right quadrant of the FLD which indicates an increased probability for crack occurrence. An optimization of the paddle shape was conducted to prevent bulging at the clamped end while avoiding crack occurrence. The paddle shape was optimized by mapping the deformation of some elements along the flange length to a pre-defined strain path on the FLD while maintaining the bulge height within the desired geometric tolerance. The radii and lengths of the paddle edge were varied to obtain an optimum paddle shape.

A Rule-Based Process Design and Finite Element Analysis of Multistage Deep Drawing of Box Shapes

2010 ◽  
Author(s):  
A. S. Wifi ◽  
R. K. Abdel-Mageid ◽  
A. H. Gomaa ◽  
M. Shazly
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Process Design ◽  
Deep Drawing ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Element Analysis ◽  
Design Algorithm ◽  
Rule Based ◽  
Thickness Variations

In this paper a computer-aided rule-based process design of multi-staged deep drawing of box shaped shells is developed. A decomposition method is adopted in the algorithm for geometry description of the part under consideration. The shell geometry, tooling dimensions and load required are determined for each stage. A finite element analysis is carried out to verify and adjust the output of this process design algorithm. The deformation severity and the resulting strains and thickness variations are investigated. The forming limit diagram (FLD) is adopted as a basic reference to monitor possible part failure in the process.

Finite Element Analysis of Creep Damage Behavior Near the Cavity on Bimaterial Interface

2006 ◽  
Vol 324-325 ◽  
pp. 951-954 ◽  
Author(s):  
Qing Min Yu ◽  
Zhu Feng Yue ◽  
Yong Shou Liu
Keyword(s):  
Finite Element ◽  
Elastic Moduli ◽  
Elastic Stress ◽  
Creep Damage ◽  
Ductile Material ◽  
Bimaterial Interface ◽  
Modulus Ratio ◽  
Element Analysis ◽  
Damage Law ◽  
The Difference

Fracture along an interface between materials plays a major role in failure of material. In this investigation, finite element calculations with Kachanov–Rabotnov damage law were carried out to study the creep damage distribution near the interface cavity in bimaterial specimens. The specimens with central hole were divided into three types. The material parameters of K-R law used in this paper were chosen for a brittle material and ductile material. All calculations were performed under four load cases. Due to the difference between elastic moduli of the bounded materials, the elastic stress field as a function of the Young’s modulus ratio (R=E1/E2) was determined. At the same time, the influence of model type on elastic stress distribution near the cavity was considered. Under the same conditions, the material with larger modulus is subjected to larger stress. The creep damage calculations show that the location of the maximum damage is different for each model. The distributions of creep damage for all three models are dependent on the material properties and load cases.

scholarly journals Finite element analysis of the grain size effect on diffusion in polycrystalline materials

2014 ◽  
Vol 95 ◽  
pp. 187-191 ◽  
Author(s):  
V. Lacaille ◽  
C. Morel ◽  
E. Feulvarch ◽  
G. Kermouche ◽  
J.-M. Bergheau
Keyword(s):  
Finite Element Analysis ◽  
Grain Size ◽  
Finite Element ◽  
Size Effect ◽  
Polycrystalline Materials ◽  
Grain Size Effect ◽  
Element Analysis

Optimization of Sheet Metal Process Parameters of a Shield Case Piece Using Computer Simulation

2006 ◽  
Vol 510-511 ◽  
pp. 330-333
Author(s):  
M.C. Curiel ◽  
Ho Sung Aum ◽  
Joaquín Lira-Olivares
Keyword(s):  
Sheet Metal ◽  
Thickness Distribution ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Physical Processes ◽  
Forming Process ◽  
Element Analysis ◽  
One Step ◽  
Range Of Values ◽  
Principal Strains

Numerical simulations based on Finite Element Analysis (FEA) are widely used to predict and evaluate the forming parameters before performing the physical processes. In the sheet metal industry, there are basically two types of FE programs: the inverse (one-step) programs and the incremental programs. In the present paper, the forming process of the shield case piece (LTA260W1-L05) was optimized by performing simulations with both types of software. The main analyzed parameter was the blankholding force while the rest of the parameters were kept constant. The criteria used to determine the optimum value was based on the Forming Limit Diagram (FLD), fracture and wrinkling of the material, thickness distribution, and the principal strains obtained. It was found that the holding force during the forming process deeply affects the results, and a range of values was established in which the process is assumed to give a good quality piece.

Simulation of Thermo-Mechanical Models for Hot Formed Parts by Numerical Experiments

2014 ◽  
Vol 663 ◽  
pp. 668-674
Author(s):  
Azman Senin ◽  
Zulkifli Mohd Nopiah ◽  
Muhammad Jamhuri Jamaludin ◽  
Ahmad Zakaria
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Prediction Accuracy ◽  
Research Work ◽  
Deformation Characteristic ◽  
Element Model ◽  
Forming Limit ◽  
Prototype Model ◽  
New Production ◽  
Element Analysis

The Finite-Element Analysis (FEA) is a prediction methodology that facilitates product designers produced the part design with manufacturing focused. With the similar advantages, manufacturing engineers are capable of build the first actual car model from the new production Draw Die. This approach has eliminated the requirement to manufacture the prototype model from soft tool parts and soft tool press die. However, the prediction accuracy of FEA is a major topic of research work in automotive sector's practitioners and academia as current accuracy level is anticipated at 60%. The objective of works is to assess the prediction accuracy on deformation results from mass production stamped parts. The Finite-element model is developed from the CAD data of the production tools. Subsequently, finite-element model for production tools is discretized with shell elements to avoid computation errors in the simulation process. The sheet blank material with 1.5 mm and 2.0 mm thickness is discredited by shell (2D modeling) and solid elements (3D modeling) respectively. The input parameters for the simulation model for both elements are attained from the actual setup at Press Machine and Production Tool. The analysis of deformation and plastic strain are performed for various setup parameters. Finally, the deformation characteristic such as Forming Limit Diagram (FLD) and thinning are compared for all simulated models.

A Comparative Study on Mechanical Behavior of Pipe-Socket Threaded Joints With Taper-Taper Threads and Taper-Parallel Threads Combinations by Finite Element Analysis and Experiments

2018 ◽  
Author(s):  
Satoshi Nagata ◽  
Shinichi Fujita ◽  
Toshiyuki Sawa
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Service Condition ◽  
Internal Thread ◽  
Element Analysis ◽  
Strain Pattern ◽  
External Thread ◽  
Thread Length ◽  
The Difference

There are two types of combination between external and internal threads used in threaded pipe connections for pressure piping specified in industrial standards like JIS as well as ISO. One is the combination that taper external thread of pipe is engaged with taper internal thread of a fitting. The other is that taper external thread of pipe is engaged with parallel internal thread of a fitting. Taper thread is always used for external thread outside the pipe wall. Both taper thread and parallel one are applicable to internal thread inside the fittings. This paper evaluates the mechanical behaviors of threaded pipe-socket joints (or pipe-coupling joints) and the difference due to the thread type combinations by means of axisymmetric finite element analysis for 3/4” and 3” joints. The analysis shows that the taper-taper threads combination establishes the full-length contact over the engaged threads but the taper-parallel has only a pair of threads in contact at the 1st engaged thread from the end of socket, and the difference results in the different behaviors of the joints. Stress and strain pattern also completely differ due to the difference in the engaged thread length. No significant effect of the size has been found in the present analysis for 3/4”and 3” joints. Experimental tightening tests and pressure leak tests have also been carried out for 3/4” and 3” joints with taper-taper threads combination. The measured experimental stress for 3/4” joints has shown an agreement with the simulated one fairly well. The pressure leak tests have demonstrated that the taper-taper threaded pipe-socket joints can hold internal pressure without leakage without using thread seal tape or jointing compound under low-pressure service condition. The 3/4” joints have started leaking at 1–4MPaG of internal pressure. The 3” joints haven’t shown leakage even at 6MPaG of internal pressure applied.

Effect of temperature and punch speed on forming limit strains of AA5182 alloy in warm forming and improvement in failure prediction in finite element analysis

2017 ◽  
Vol 52 (4) ◽  
pp. 258-273 ◽  
Author(s):  
D Raja Satish ◽  
D Ravi Kumar ◽  
Marion Merklein
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Rate ◽  
Deep Drawing ◽  
Failure Prediction ◽  
Forming Limit ◽  
Element Analysis ◽  
Working Temperature ◽  
Warm Working ◽  
Punch Speed

Formability of AA5182-O aluminum alloy sheets in the warm working temperature range has been studied. Forming limit strains of sheets of two different thicknesses have been determined experimentally in different modes of deformation (biaxial tension, plane strain and tension–compression) by varying temperature and punch speed. A correlation has been established for plane strain intercept of the forming limit diagram (FLD0) with temperature, punch speed and thickness from the experimental results. This correlation has been used to plot the forming limit diagrams for failure prediction in the finite element analysis of warm deep drawing of cylindrical cups. The effect of strain and strain rate on material flow behavior has been incorporated using a strain rate–sensitive power hardening law in which the strain hardening exponent and strain rate sensitivity index have been experimentally determined. The predictions from simulations have been validated by warm deep drawing experiments. Large improvement in accuracy of failure prediction has been observed using the FLDs plotted based on the developed correlation when compared to the existing method of calculating FLD0 using only strain hardening coefficient and thickness. The results clearly indicate the importance of incorporating temperature and punch speed in failure prediction of Al alloys using FLDs in the warm working temperature range.

Analysis of Three Dimensional Nonlinear Coupled Finite Element Based on some Concrete Rock-Fill Dam

2014 ◽  
Vol 998-999 ◽  
pp. 522-525
Author(s):  
Juan Juan Jin ◽  
Min He ◽  
Peng Liu
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
High Plasticity ◽  
Element Analysis ◽  
Rock Fill ◽  
Arching Effect ◽  
Earth Core ◽  
Gravel Soil ◽  
High Plasticity Clay ◽  
The Difference

As the future highest dam in the world, Shuang Jiang Kou rock-fill dam was the water retaining structure of homonymous hydropower station, a controlling engineering on Da Du River hydropower development, which is under design now. This dam is a central earth core dam with a height of 312 meters. A type of gravel soil stiffer than clay, which is made by artificial compounding of clay and gravel, is introduced to reduce the difference in displacement of earth core and rock filled shell zone. Because of the introduced less flexible central core, a more remarkable arching effect of the abutment on earth core might occur simultaneously. A three dimensional coupled nonlinear finite element analysis is carried out to study the three dimensional arching effect of Shuang Jiang Kou rock-fill dam. Computation results show that the arching effect is much notable. Then an innovation is proposed in design, in which a contact high-plasticity clay layer is introduced. It is verified that this innovation is effective and necessary.

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