Modeling and Optimization of Pressure Profile in Hydroforming of St12 Conic Part with RSM and Genetic Algorithm

2011 ◽  
Vol 473 ◽  
pp. 587-593
Author(s):  
Hamzeh Shahrajabian ◽  
Khalil Khalili ◽  
M. Soheil Khalili
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Element Model ◽  
Pressure Profile ◽  
Hydraulic Pressure ◽  
Response Surface Modeling ◽  
Optimum Pressure ◽  
Pressure Profiles ◽  
Hydroforming Process ◽  
The Finite Element Model

One of the most effective methods of manufacturing conical parts is the hydroforming process. The pressure profile during forming is the most important factor on wrinkling, thinning, and punch wall contact. This paper presents a methodology to determine the optimal profile of hydraulic pressure during hydroforming of conical parts. The objective is to minimize the variation of the thickness throughout the part. Initially, the finite element model is developed and verified. The part being modeled is then subjected to different pressure profiles to examine the effect of each profile on thinning. The Response Surface Modeling (RSM) along with Genetic Algorithm (GA) is employed to obtain the optimum pressure profile. The paper describes the methodology developed and reports the results obtained.

The Stress Analysis for the Trenchless Pipeline Rehabilitation

2005 ◽  
Author(s):  
Kuang-Chyi Lee ◽  
Rong-Yuan Jou ◽  
Hsin Her Yu ◽  
Yuan-Cheng Liang ◽  
Chien-Chang Lin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Analysis ◽  
Heavy Traffic ◽  
Element Model ◽  
Hydraulic Pressure ◽  
Optimal Thickness ◽  
Plastic Sheet ◽  
Different Types ◽  
The Finite Element Model

Most of the pipelines will get aging year after year and then they will need to be rehabilitated. Because of the heavy traffic on the ground or the congested pipelines under the ground, the replacement of old pipes will be very difficult in the cities. The dig-free (trenchless) method is a revolutionary pipelining method which uses air pressure, hydraulic pressure or mechanical drag force to pull the flexible piping plastic sheet into the old pipe. This research proposes a stress analysis for trenchless pipeline method by the finite element model with CATIA. The material of piping sheet is combined of two different types of epoxy with the anionic harder. We do the stress analysis of the trenchless rehabilitated pipelines to decide the optimal thickness of flexible piping plastic sheet and whether the material is available or not by 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 Springback prediction of CP2 titanium sheets in hydroforming with membrane diaphragm process with finite element method

2018 ◽  
Vol 190 ◽  
pp. 09002
Author(s):  
Cahit Sertac Aydogan ◽  
Hasan Ali Hatipoglu ◽  
Omer Keles
Keyword(s):  
Finite Element Method ◽  
Experimental Investigation ◽  
Finite Element ◽  
Numerical Model ◽  
Sheet Metal ◽  
Element Model ◽  
Hydroforming Process ◽  
Metal Titanium ◽  
Springback Prediction ◽  
The Finite Element Model

This study aims to predict and to examine the springback of CP2 Titanium sheets in hydroforming with membrane diaphragm process, which is the branch of hydroforming process. The Hydroforming with Membrane Diaphragm was used for experimental investigation, in which specified CP2 titanium sheets were bent with various radii and angles on a specifically designed die. Springback results were then used to validate the finite element model constructed previously. Results show that the numerical model of this study can be used to predict the approximate springback values. Thus, the scrap quantities of the sheet metal titanium products can be reduced by making some modifications on the die, such as the springback compensation based on the obtained approximate springback values.

The Finite Element Model Updating Based on Multi-Case Displacement Measurement

2013 ◽  
Vol 353-356 ◽  
pp. 3378-3381
Author(s):  
Ye Yan Liu ◽  
Jun Xiao ◽  
Yu Xin Zhang
Keyword(s):  
Genetic Algorithm ◽  
Inverse Problem ◽  
Finite Element ◽  
Elastic Modulus ◽  
Model Updating ◽  
Element Model ◽  
Finite Element Model Updating ◽  
Improved Genetic Algorithm ◽  
Numerical Examples ◽  
The Finite Element Model

Elastic modulus is an important parameter in structural analysis. This paper identifys the structural elastic modulus with measured displacements, which is an inverse problem. The improved genetic algorithm combined with multi-cases measurement is applied in the solution. Numerical examples have proved that the method is available.

Redrawing Operation a Star Shape from Cylindrical Shape Using Experimental and FE Analysis

2020 ◽  
Vol 38 (1A) ◽  
pp. 25-32
Author(s):  
Waleed Kh. Jawad ◽  
Ali T. Ikal
Keyword(s):  
Finite Element ◽  
Effective Strain ◽  
Element Model ◽  
Cylindrical Shape ◽  
Element Analysis ◽  
Punch Force ◽  
Maximum Value ◽  
Element Simulation ◽  
Blank Sheet ◽  
The Finite Element Model

The aim of this paper is to design and fabricate a star die and a cylindrical die to produce a star shape by redrawing the cylindrical shape and comparing it to the conventional method of producing a star cup drawn from the circular blank sheet using experimental (EXP) and finite element simulation (FES). The redrawing and drawing process was done to produce a star cup with the dimension of (41.5 × 34.69mm), and (30 mm). The finite element model is performed via mechanical APDL ANSYS18.0 to modulate the redrawing and drawing operation. The results of finite element analysis were compared with the experimental results and it is found that the maximum punch force (39.12KN) recorded with the production of a star shape drawn from the circular blank sheet when comparing the punch force (32.33 KN) recorded when redrawing the cylindrical shape into a star shape. This is due to the exposure of the cup produced drawn from the blank to the highest tensile stress. The highest value of the effective stress (709MPa) and effective strain (0.751) recorded with the star shape drawn from a circular blank sheet. The maximum value of lamination (8.707%) is recorded at the cup curling (the concave area) with the first method compared to the maximum value of lamination (5.822%) recorded at the cup curling (the concave area) with the second method because of this exposure to the highest concentration of stresses. The best distribution of thickness, strains, and stresses when producing a star shape by

Analysis of Hydroelectric Unit’s Upper Bracket Based on Test and FEM

2014 ◽  
Vol 721 ◽  
pp. 131-134
Author(s):  
Mi Mi Xia ◽  
Yong Gang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Element Model ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Element Analysis ◽  
Hydroelectric Unit ◽  
The Finite Element Analysis ◽  
Strain Rosette ◽  
The Finite Element Model

To research the load upper bracket of Francis hydroelectric unit, then established the finite-element model, and analyzed the structure stress of 7 operating condition points with the ANSYS software. By the strain rosette test, acquired the data of stress-strain in the area of stress concentration of the upper bracket. The inaccuracy was considered below 5% by analyzing the contradistinction between the finite-element analysis and the test, and match the engineering precision and the test was reliable. The finite-element method could be used to judge the stress of the upper bracket, and it could provide reference for the Structural optimization and improvement too.

Analysis of Premium Connection of Connecting and Sealing Ability Loaded by Axial Tensile Loads

2012 ◽  
Vol 268-270 ◽  
pp. 737-740
Author(s):  
Yang Yu ◽  
Yi Hua Dou ◽  
Fu Xiang Zhang ◽  
Xiang Tong Yang
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Tensile Load ◽  
Element Model ◽  
Sealing Ability ◽  
Axial Tensile ◽  
High Level ◽  
Maximum Contact ◽  
Contact Pressures ◽  
The Finite Element Model

It is necessary to know the connecting and sealing ability of premium connection for appropriate choices of different working conditions. By finite element method, the finite element model of premium connection is established and the stresses of seal section, shoulder zone and thread surface of tubing by axial tensile loads are analyzed. The results show that shoulder zone is subject to most axial stresses at made-up state, which will make distribution of stresses on thread reasonable. With the increase of axial tensile loads, stresses of thread on both ends increase and on seal section and shoulder zone slightly change. The maximum stress on some thread exceed the yield limit of material when axial tensile loads exceed 400KN. Limited axial tensile loads sharply influence the contact pressures on shoulder zone while slightly on seal section. Although the maximum contact pressure on shoulder zone drop to 0 when the axial tensile load is 600KN, the maximum contact pressure on seal section will keep on a high level.

The structural optimization of roadheader conical picks based on fatigue life

2018 ◽  
Vol 09 (02) ◽  
pp. 1850013 ◽  
Author(s):  
Zhenguo Lu ◽  
Lirong Wan ◽  
Qingliang Zeng ◽  
Xin Zhang ◽  
Kuidong Gao
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Static Analysis ◽  
Element Model ◽  
Cutting Resistance ◽  
Strength Failure ◽  
New Type ◽  
Conical Picks ◽  
Fatigue Life Analysis ◽  
The Finite Element Model

Conical picks are the key cutting components used on roadheaders, and they are replaced frequently because of the bad working conditions. Picks did not meet the fatigue life when they were damaged by abrasion, so the pick fatigue life and strength are excessive. In the paper, in order to reduce the abrasion and save the materials, structure optimization was carried out. For static analysis and fatigue life prediction, the simulation program was proposed based on mathematical models to obtain the cutting resistance. Furthermore, the finite element models for static analysis and fatigue life analysis were proposed. The results indicated that fatigue life damage and strength failure of the cutting pick would never happen. Subsequently, the initial optimization model and the finite element model of picks were developed. According to the optimized results, a new type of pick was developed based on the working and installing conditions of the traditional pick. Finally, the previous analysis methods used for traditional methods were carried out again for the new type picks. The results show that new type of pick can satisfy the strength and fatigue life requirements.

Analysis of Packer Rubber Mechanics Properties

2014 ◽  
Vol 971-973 ◽  
pp. 380-389
Author(s):  
Jian Ning Wang ◽  
Gang Wu ◽  
Wei Yi Xie ◽  
Xin De Han ◽  
Ming Chao Gang
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Constitutive Model ◽  
Contact Stress ◽  
Theoretical Basis ◽  
Element Model ◽  
Rubber Material ◽  
Bottom Hole ◽  
Sealing Performance ◽  
The Finite Element Model

Abstract: The packer rubber stress in the bottom hole is more complex. Based on constitutive model of the packer rubber material, this paper determines such parameters as model constants, Poisson's ratio of rubber materials and elastic modulus by using experimental method, to build up the finite element model of center tube-rubber cylinder-casing for the purpose of stress analysis. Finally, the distribution regularity of rubber cylinder-casing contact stress and packer setting travel distance with varying loads is concluded. The results can provide the theoretical basis for further analysis of packer rubber sealing performance.

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