scholarly journals Numerical Investigation of Temperature and Forming Rate Effect on AA5086 Warm Formability

2011 ◽  
Vol 675-677 ◽  
pp. 607-610
Author(s):  
Cun Sheng Zhang ◽  
Guo Qun Zhao ◽  
Hao Chen ◽  
Lionel Leotoing
Keyword(s):  
Constitutive Law ◽  
Forming Process ◽  
Finite Element Program ◽  
Marciniak Test ◽  
Complex Shapes ◽  
Sheet Formability ◽  
Forming Temperature ◽  
Element Program ◽  
Dynamic Tensile Test ◽  
Parameter Values

The poor formability of aluminum alloy at room temperature limits its use in some products with complex shapes, hence the warm forming process is intended to overcome this problem by using an elevated temperature. Now, the warm formability of AA5086 has not previously been well investigated in the literatures, especially at a rapid forming rate. In this paper, a numerical method has been developed to investigate the warm formability of an AA5086 sheet. Firstly, the dynamic tensile test was carried out under different forming temperatures and forming rates to identify an appropriate constitutive law for the sheet. The inverse analysis was performed to identify the parameter values in the constitutive law. Then based on the commercial finite element program ABAQUS, the Marciniak test was simulated to evaluate the sheet formability of by implementing a user-defined material subroutine UHARD. The effects of forming temperature and forming rate on sheet formability were investigated and it is shown that the formability of AA5086 seems to be insensitive to the forming temperature and forming rate.

Designing Hot Working Processes of Nickel Base Superalloys Using FEM Simulation

2001 ◽  
Author(s):  
R. Kopp ◽  
M. Tschirnich ◽  
M. Wolske ◽  
J. Klöwer
Keyword(s):  
Testing Machine ◽  
Fem Simulation ◽  
Material Model ◽  
Hydraulic Testing ◽  
Compression Tests ◽  
Finite Element Program ◽  
Real Process ◽  
Forming Temperature ◽  
Element Program ◽  
Nickel Base

Knowledge of correct flow stress curves of Ni-based alloys at high temperatures is of essential importance for reliable plasto-mechanical simulations in materials processing and for an effective planning and designing of industrial hot forming schedules like hot rolling or forging. The experiments are performed on a computer controlled servo-hydraulic testing machine at IBF (Institute of Metal Forming). To avoid an inhomogeneous deformation due to the influence of friction and initial microstructure, a suitable specimen geometry and lubricant is used and a thermal treatment before testing has to provide a microstructure, similar to the structure of the material in the real process. The compression tests are performed within a furnace, which keeps sample, tools and surrounding atmosphere at the defined forming temperature. The uniaxial compressions were carried out in the range of strain rates between 0.001 and 50 s−1 and temperatures between 950 and 1280°C. Furthermore two-stage step tests are carried out to derive the work hardening and softening behaviour as well as the recrystallisation kinetics of the selected Ni-based alloys. At the end of this work a material model is adapted by the previously determined material data. This model is integrated into the Finite Element program LARSTRAN/SHAPE to calculate a forging process of the material Alloy 617.

Plastic Deformation Theory Application in Finite Element Analysis

2012 ◽  
Vol 594-597 ◽  
pp. 2723-2726
Author(s):  
Wen Shan Lin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Deformation Theory ◽  
Three Dimensional ◽  
Constitutive Laws ◽  
Constitutive Law ◽  
Element Analysis ◽  
Finite Element Program ◽  
Theory Of Plasticity ◽  
Element Program

In the present study, the constitutive law of the deformation theory of plasticity has been derived. And that develop the two-dimensional and three-dimensional finite element program. The results of finite element and analytic of plasticity are compared to verify the derived the constitutive law of the deformation theory and the FEM program. At plastic stage, the constitutive laws of the deformation theory can be expressed as the linear elastic constitutive laws. But, it must be modified by iteration of the secant modulus and the effective Poisson’s ratio. Make it easier to develop finite element program. Finite element solution and analytic solution of plasticity theory comparison show the answers are the same. It shows the derivation of the constitutive law of the deformation theory of plasticity and finite element analysis program is the accuracy.

Comparison of a Multi-Layer Structural Model for Arterial Walls With a Fung-Type Model, and Issues of Material Stability

2004 ◽  
Vol 126 (2) ◽  
pp. 264-275 ◽  
Author(s):  
Gerhard A. Holzapfel ◽  
Thomas C. Gasser ◽  
Ray W. Ogden
Keyword(s):  
Structural Model ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Strain Energy Function ◽  
Point Of View ◽  
Constitutive Law ◽  
Type Model ◽  
Finite Element Program ◽  
Highly Nonlinear ◽  
Element Program

The goals of this paper are (i) to re-examine the constitutive law for the description of the (passive) highly nonlinear and anisotropic response of healthy elastic arteries introduced recently by the authors, (ii) to show how the mechanical response of a carotid artery under inflation and extension predicted by the structural model compares with that for a three-dimensional form of Fung-type strain-energy function, (iii) to provide a new set of material parameters that can be used in a finite element program, and (iv) to show that the model has certain mathematical features that are important from the point of view of material and numerical stability.

Delamination of Laminates Governed by Free Edge Interlaminar Stresses Using Interface Element

2008 ◽  
Vol 385-387 ◽  
pp. 821-824 ◽  
Author(s):  
Hossein Hosseini-Toudeshky ◽  
Meisam Jalalvand ◽  
Bijan Mohammadi
Keyword(s):  
Free Edge ◽  
Constitutive Law ◽  
Interface Element ◽  
Shear Stresses ◽  
Interlaminar Stresses ◽  
Finite Element Program ◽  
Element Program ◽  
Failure Loads ◽  
The Difference ◽  
Interlaminar Shear

In this paper, interface element with de-cohesive constitutive law is used to predict the delamination progress of laminates in which delamination is the prominent failure mode. For this purpose, a finite element program is developed to perform nonlinear damage analysis. The analyses are carried out based on the interlaminar constitutive law of elastic-plastic-damage proposed before in the literature. Delamination initiation and propagation of several laminates with dominant interlaminar shear stresses at free edges are investigated to find the failure load. It is shown that the difference between the predicted failure loads using the present study and the experimental results are 3.1% to 19.4% for various laminates.

Designing Hot Working Processes of Nickel-Based Superalloys Using Finite Element Simulation

2002 ◽  
Vol 124 (4) ◽  
pp. 931-935 ◽  
Author(s):  
R. Kopp ◽  
M. Tschirnich ◽  
M. Wolske ◽  
J. Klo¨wer
Keyword(s):  
Finite Element ◽  
Testing Machine ◽  
Material Model ◽  
Compression Tests ◽  
Finite Element Program ◽  
Softening Behavior ◽  
Real Process ◽  
Element Simulation ◽  
Forming Temperature ◽  
Element Program

Knowledge of correct flow stress curves of Ni-based alloys at high temperatures is of essential importance for reliable plastomechanical simulations in materials processing and for an effective planning and designing of industrial hot forming schedules like hot rolling or forging. The experiments are performed on a computer controlled servohydraulic testing machine at IBF. To avoid an inhomogeneous deformation due to the influence of friction and initial microstructure, a suitable specimen geometry and lubricant is used and a thermal treatment before testing has to provide a microstructure, similar to the structure of the material in the real process. The compression tests are performed within a furnace, which keeps sample, tools, and surrounding atmosphere on the defined forming temperature. The uniaxial compressions were carried out in the range of strain rates between 0.001 and 50s−1 and temperatures between 950 and 1280°C. Furthermore, two-stage step tests are carried out to derive the work hardening and softening behavior as well as the recrystallization kinetics of the selected Ni-based alloys. At the end of this work a material model is adapted by the previously determined material data. This model is integrated into the Finite Element program LARSTRAN/SHAPE to calculate a forging process of the material Alloy 617.

Friction Force and Stresses Analysis for Contact of Assembled Details

2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Plastic Deformation ◽  
Friction Force ◽  
Sliding Friction ◽  
Friction Model ◽  
Contact Interface ◽  
Finite Element Program ◽  
Elastic Plastic ◽  
Element Program

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Mechanical Property Analysis and Numerical Simulation of Honeycomb Sandwich Structure’s Core

2013 ◽  
Vol 631-632 ◽  
pp. 518-523 ◽  
Author(s):  
Xiang Li ◽  
Min You
Keyword(s):  
Numerical Simulation ◽  
Elastic Constants ◽  
Sandwich Structure ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Finite Element Program ◽  
Honeycomb Sandwich ◽  
Calculation Results ◽  
Element Program ◽  
Typical Satellite

Owing to the lack of a good theory method to obtain the accurate equivalent elastic constants of hexagon honeycomb sandwich structure’s core, the paper analyzed mechanics performance of honeycomb sandwich structure’s core and deduced equivalent elastic constants of hexagon honeycomb sandwich structure’s core considering the wall plate expansion deformation’s effect of hexagonal cell. And also a typical satellite sandwich structure was chose as an application to analyze. The commercial finite element program ANSYS was employed to evaluate the mechanics property of hexagon honeycomb core. Numerical simulation analysis and theoretical calculation results show the formulas of equivalent elastic constants is correct and also research results of the paper provide theory basis for satellite cellular sandwich structure optimization design.

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