Numerical Analysis of Superplastic Bulging Process of TiAl Sheet

2013 ◽  
Vol 747-748 ◽  
pp. 50-56
Author(s):  
Chuan Yun Wang ◽  
Jin Shan Li ◽  
Bin Tang ◽  
Hong Chao Kou
Keyword(s):  
Present Model ◽  
Thickness Distribution ◽  
Equivalent Plastic Strain ◽  
Element Model ◽  
Dominant Factor ◽  
Tial Alloys ◽  
Deformation Parameters ◽  
Nonuniform Thickness ◽  
Simulation Results ◽  
Good Agreement

The superplastic bulging process of TiAl sheet was simulated by coupling superplastic constitutive equation to finite element model. Based on this model, the effect of coefficient of friction between the sheet and mold and the size of the mold fillet on the superplastic bulging (SPB) performance of TiAl alloys sheet were studied by analyzing the evolution of equivalent plastic strain and thickness distribution in the sheet. The results showed that friction was the dominant factor of the nonuniform thickness of the sheet, while higher friction and smaller radius of mold fillet inhibited the over-thinning of sheet on the entry of mold cavity. The simulation results were in good agreement with the experimental results. Therefore, the present model could be used for optimizing the selction of the deformation parameters and the design of the structures.

scholarly journals Investigation of the Thickness Differential on the Formability of Aluminum Tailor Welded Blanks

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 875
Author(s):  
Jie Wu ◽  
Yuri Hovanski ◽  
Michael Miles
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Model ◽  
Plastic Strain ◽  
Finite Element Model ◽  
Equivalent Plastic Strain ◽  
Element Model ◽  
Dome Height ◽  
Tailor Welded Blanks ◽  
Simulation Results

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.

Electrothermally Tunable Bridge Resonator

2016 ◽  
Author(s):  
Amal Z. Hajjaj ◽  
Nouha Alcheikh ◽  
Abdallah Ramini ◽  
Md Abdullah Al Hafiz ◽  
Mohammad I. Younis
Keyword(s):  
Fundamental Frequency ◽  
Beam Theory ◽  
Element Model ◽  
Bernoulli Beam ◽  
Electrothermal Actuation ◽  
Wide Range ◽  
Simulation Results ◽  
Dc Current ◽  
Euler Bernoulli Beam ◽  
Good Agreement

This paper demonstrates experimentally, theoretically, and numerically a wide-range tunability of an in-plane clamped-clamped microbeam, bridge, and resonator compressed by a force due to electrothermal actuation. We demonstrate that a single resonator can be operated at a wide range of frequencies. The microbeam is actuated electrothermally, by passing a DC current through it. We show that when increasing the electrothermal voltage, the compressive stress inside the microbeam increases, which leads eventually to its buckling. Before buckling, the fundamental frequency decreases until it drops to very low values, almost to zero. After buckling, the fundamental frequency increases, which is shown to be as high as twice the original resonance frequency. Analytical results based on the Galerkin discretization of the Euler Bernoulli beam theory are generated and compared to the experimental data and to simulation results of a multi-physics finite-element model. A good agreement is found among all the results.

Three Dimension Finite Element Model for Neck-Spinning Process of Tube at Elevated Temperature

2011 ◽  
Vol 110-116 ◽  
pp. 2708-2716
Author(s):  
Ching Hua Huang ◽  
Ching Hua Hung ◽  
Jung Chung Hung ◽  
Chia Rung Lin
Keyword(s):  
Elevated Temperature ◽  
Thickness Distribution ◽  
Shell Element ◽  
Element Model ◽  
Scaling Factor ◽  
Strain Rates ◽  
Three Dimension ◽  
Mass Scaling ◽  
Spinning Process ◽  
Simulation Results

The aim of this research is to investigate numerically the neck-spinning process of a tube at elevated temperature. The commercial software Abaqus/Explicit was adopted in the simulation. For the construction of the material model, special uni-axial tensile tests were conducted at elevated temperature and various strain rates, since the material is sensitive to strain rates at high temperature. The influence of the element type and mass scaling factor were investigated through numerical simulation. Full-integration shell element is the better choice in the simulation of the neck-spinning process at elevated temperature. The use of suitable mass scaling factor will make the analysis more efficiency. Comparisons between experimental and simulation results on thickness distribution and the outer contour of the spun tube are discussed. Good agreement was found between experimental and simulation results.

scholarly journals Numerical and Experimental Results on Charpy Tests for Blends Polypropylene + Polyamide + Ethylene Propylene Diene Monomer (PP+PA+EDPM)

2020 ◽  
Author(s):  
Catalin Pirvu ◽  
Andreea Elena Musteata ◽  
George Ghiocel Ojoc ◽  
Lorena Deleanu
Keyword(s):  
Equivalent Plastic Strain ◽  
Material Model ◽  
Element Model ◽  
Tensile Tests ◽  
Experimental Results ◽  
Low Velocity ◽  
Sem Images ◽  
Charpy Test ◽  
Simulation Results ◽  
The Impact

This paper presents results from numerical and experimental investigation on Charpy tests in order to point out failure mechanisms and to evaluate new polymeric blends PP+PA6+EPDM. Charpy tests were done for initial velocity of the impactor of 0.96 m/s and its mass of 3.219 kg and these data were also introduced in the finite element model. The proposed model take into account the system of four balls, including support and the ring of fixing the three balls and it has a finer discretization of the impact area to highlight the mechanisms of failure and their development in time. The constitutive models for four materials (polypropylene with 1% Kritilen, two blends PP+PA6+EPDM and a blend PA6+EPDM) were derived from tensile tests. Running simulations for each constitutive model of material makes possible to differentiate the destruction mechanisms according to the material introduced in the simulation, including the initiation and the development of the crack(s), based on equivalent plastic strain at break (EPS) for each material. The validation of the model and the simulation results was done qualitatively, analysing the shape of broken surfaces and comparing them to SEM images and quantitatively by comparing the impact duration, energy absorbed by the sample, the value of maximum force during impact. The duration of the destruction of the specimen is longer than the actual one, explainable by the fact that the material model does not take into account the influence of the material deformation speed in Charpy test, the model being designed with the help of tests done at 0.016 m/s (1000 mm/min) (maximum strain rate for the tensile tests). Experimental results are encouraging for recommending the blends 20% PP+42% PA6+28% EPDM and 60% PA6+ 40%EPDM as materials for impact protection at low velocity (1m/s). Simulation results are closer to the experimental ones for the more brittle tested materials (with less content of PA6 and EPDM) and more distanced for the more ductile materials (with higher content of PA6 and EPDM).

Study on Hydraulic Deep Drawing of Square Cups

2014 ◽  
Vol 626 ◽  
pp. 334-339
Author(s):  
Te Fu Huang ◽  
Hsin Yi Hsien ◽  
Yan Jia Chen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Deep Drawing ◽  
Thickness Distribution ◽  
The Finite Element Method ◽  
Experimental Apparatus ◽  
Punch Load ◽  
Simulation Results ◽  
Good Agreement ◽  
Element Method

The friction holding effect and the friction reducing effect occurring during Hydraulic Deep Drawing and the pre-bulging resulting in more plastic deformation on products are applied on sheet hydro-forming. For Hydraulic Deep Drawing of a square cup, the thickness distribution and the relation between the height and the pressure of pre-bulging are simulated with SPCC steels as the specimen by the finite element method. An experimental apparatus of sheet hydro-forming has been constructed to carry out the hydraulic deep drawing experiments of square cups. Experimental thickness distribution and punch load are compared with simulation results. Good agreement was found. The flow patterns of the circular and square blanks with the condition of being firmly pressed against the punch observed from the experiments are in agreement with the predicted results.Keywords:Hydraulic Deep Drawing, sheet hydro-forming, finite element method

Investigation on the Effect of Pulsating Pressure on Tube-Hydroforming Process

2011 ◽  
Vol 473 ◽  
pp. 618-623
Author(s):  
Khalil Khalili ◽  
Seyed Yousef Ahmadi-Brooghani ◽  
Amir Ashrafi
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Element Model ◽  
Fe Model ◽  
Axial Feeding ◽  
Hydroforming Process ◽  
The Finite Element Model ◽  
Good Agreement

Tube hydroforming process is one of the metal forming processes which uses internal pressure and axial feeding simultaneously to form a tube into the die cavity shape. This process has some advantages such as weight reduction, more strength and better integration of produced parts. In this study, T-shape tube hydroforming was analyzed by experimental and finite element methods. In Experimental method the pulsating pressure technique without counterpunch was used; so that the internal pressure was increased up to a maximum, the axial feeding was then stopped. Consequently, the pressure decreased to a minimum. The sequence was repeated until the part formed to its final shape. The finite element model was also established to compare the experimental results with the FE model. It is shown that the pulsating pressure improves the process in terms of maximum protrusion height obtained. Counterpunch was eliminated as being unnecessary. The results of simulation including thickness distribution and protrusion height were compared to the part produced experimentally. The result of modeling is in good agreement with the experiment. The paper describes the methodology and gives the results of both experiment and modeling.

scholarly journals Numerical and Experimental Results on Charpy Tests for Blends Polypropylene + Polyamide + Ethylene Propylene Diene Monomer (PP + PA + EPDM)

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5837
Author(s):  
Cătălin Pîrvu ◽  
Andreea Elena Musteată ◽  
George Ghiocel Ojoc ◽  
Lorena Deleanu
Keyword(s):  
Equivalent Plastic Strain ◽  
Material Model ◽  
Element Model ◽  
Tensile Tests ◽  
Experimental Results ◽  
Low Velocity ◽  
Sem Images ◽  
Charpy Test ◽  
Simulation Results ◽  
The Impact

This paper presents results from numerical and experimental investigation on Charpy tests in order to point out failure mechanisms and to evaluate new polymeric blends PP + PA6 + EPDM. Charpy tests were done for initial velocity of the impactor of 0.96 m/s and its mass of 3.219 kg and these data were also introduced in the finite element model. The proposed model takes into account the system of four balls, including support and the ring of fixing the three balls and it has a finer discretization of the impact area to highlight the mechanisms of failure and their development in time. The constitutive models for four materials (polypropylene with 1% Kritilen, two blends PP + PA6 + EPDM and a blend PA6 + EPDM) were derived from tensile tests. Running simulations for each constitutive model of material makes possible to differentiate the destruction mechanisms according to the material introduced in the simulation, including the initiation and the development of the crack(s), based on equivalent plastic strain at break (EPS) for each material. The validation of the model and the simulation results were done qualitatively, analyzing the shape of broken surfaces and comparing them to SEM images and quantitatively by comparing the impact duration, energy absorbed by the sample, the value of maximum force during impact. The duration of the destruction of the specimen is longer than the actual one, explainable by the fact that the material model does not take into account the influence of the material deformation speed in Charpy test, the model being designed with the help of tests done at 0.016 m/s (1000 mm/min) (maximum strain rate for the tensile tests). Experimental results are encouraging for recommending the blends 20% PP + 42% PA6 + 28% EPDM and 60% PA6 + 40% EPDM as materials for impact protection at low velocity (1 m/s). Simulation results are closer to the experimental ones for the more brittle tested materials (with less content of PA6 and EPDM) and more distanced for the more ductile materials (with higher content of PA6 and EPDM).

Numerical Simulation and Experimental Verification of Disc Cutter Rings in Die Forging Process

2021 ◽  
Vol 13 (1) ◽  
pp. 131-139
Author(s):  
Luhan Hao ◽  
Tao Wang ◽  
Kangping Fu ◽  
Zhengyang Zhao ◽  
Yun Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Metal Flow ◽  
Element Model ◽  
Disc Cutter ◽  
Forging Process ◽  
Die Forging ◽  
Plastic Forming ◽  
Simulation Results ◽  
The Finite Element Model ◽  
Good Agreement

In order to study the forming law of the disc cutter ring in the independently researched die, the finite element model (FEM) of disc cutter ring for die forging has been established and the die forging process has been simulated by the plastic forming software. The metal flow field, temperature field, stress and strain field of the filling process were obtained by simulation. The exerted force of the die was also simulated and analyzed; thus, the die forging process was optimized. Based on the designed process parameters and simulation results, the experimental study on die forging forming of cutter ring was carried out. The comparison shows that the numerical simulation results are in good agreement with the experimental results, which proves that the die forging model of disc cutter ring in this paper is feasible.

Inward Flow of Surface Materials at Back-Ends of Billets During Al-Extrusion, Part 1: A Finite Element Model

1999 ◽  
Vol 121 (3) ◽  
pp. 321-327 ◽  
Author(s):  
Jin Hou
Keyword(s):  
Finite Element ◽  
Surface Layer ◽  
Outer Surface ◽  
Metal Flow ◽  
Hot Extrusion ◽  
Element Model ◽  
Surface Material ◽  
Rigid Plastic ◽  
Simulation Results ◽  
Good Agreement

In hot extrusion of Al-profiles, the billet-container boundary is characterized by the sticking condition. The outer surface layer of the billet is stuck to the container wall. At the back-end of the billet, the metal flow is complicated. The surface material, which is initially stuck to the wall, will be scraped away by the pad and flow inward into the billet. This kind of inward flow of surface material is usually undesirable and it is important to control such flow so that no surface material should be found in extruded profiles. In order to study this phenomenon, a model is proposed for the metal flow at the back-end, in which the rigid-plastic FEM is used. A computer program FEMBA has been developed based on the model. The simulation results are in qualitatively good agreement with experiments.

Numerical Simulation of Different Clamping Modes on Stretch Forming Parts

2011 ◽  
Vol 189-193 ◽  
pp. 1922-1925 ◽  
Author(s):  
Xue Chen ◽  
Mine Zhe Li ◽  
Wen Zhi Fu ◽  
Zhong Yi Cai
Keyword(s):  
Finite Element ◽  
Thickness Distribution ◽  
Finite Element Models ◽  
Stretch Forming ◽  
Forming Quality ◽  
Finite Element Software ◽  
Simulation Results ◽  
Clamping Device ◽  
Better Than ◽  
Good Agreement

Three clamping devices of stretch forming machine were introduced, and the corresponding finite element models of the spherical parts were built by finite element software, the strain and thickness distribution of the forming parts were comparatively analyzed. The simulation results show that strain and thickness distribution of the forming parts with the multiple discrete gripper clamping mode are well-proportioned, its forming quality gets better than that with the whole flat gripper and adjustable curved gripper clamping modes. The experiment was performed and a typical spherical parts was formed with the multiple discrete gripper clamping mode. The experimental results are in good agreement with simulation results, which proves feasibility and practicability of the multiple discrete gripper clamping device of stretch forming machine.

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