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.

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.

The role of material model in the finite element simulation of high-speed machining of Ti6Al4V

2016 ◽  
Vol 230 (17) ◽  
pp. 2959-2967 ◽  
Author(s):  
Chong-Yang Gao ◽  
Liang-Chi Zhang ◽  
Peng-Hui Liu
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
High Speed ◽  
Material Model ◽  
Machining Process ◽  
High Speed Machining ◽  
Serrated Chip ◽  
Finite Element Program ◽  
Element Simulation ◽  
Improved Model

This paper provides a comprehensive assessment on some commonly used thermo-viscoplastic constitutive models of metallic materials during severe plastic deformation at high-strain rates. An hcp model previously established by us was improved in this paper to enhance its predictability by incorporating the key saturation characteristic of strain hardening. A compensation-based stress-updating algorithm was also developed to introduce the new hcp model into a finite element program. The improved model with the developed algorithm was then applied in finite element simulation to investigate the high-speed machining of Ti6Al4V. It was found that by using different material models, the simulated results of cutting forces, serrated chip morphologies, and residual stresses can be different too and that the improved model proposed in this paper can be applied to simulate the titanium alloy machining process more reliably due to its physical basis when compared with some other empirical Johnson–Cook models.

Computer Aided Modeling of Deep-Drawing

2007 ◽  
Vol 344 ◽  
pp. 341-348
Author(s):  
Mehmet Ali Pişkin ◽  
Bilgin Kaftanoğlu
Keyword(s):  
Finite Element ◽  
Deep Drawing ◽  
Plastic Material ◽  
Yield Criterion ◽  
Shell Element ◽  
Material Model ◽  
Industrial Applications ◽  
Finite Element Program ◽  
Element Program ◽  
Von Mises

Deep-drawing operations are performed widely in industrial applications. It is very important for efficiency to achieve parts with no defects. In this work, a finite element method is developed to simulate deep-drawing operation including wrinkling. A four nodded five degree of freedom shell element is formulated. Isotropic elasto-plastic material model with Von Mises yield criterion is used. By using this shell element, the developed code can predict the bending behavior of workpiece besides membrane behavior. Simulations are carried out with four different element sizes. The thickness strain and nodal displacement values obtained are compared with results of a commercial finite element program and results of previously conducted experiments.

Parametric Study on Simulation Modeling of Diameter-Expanded Conductor

2013 ◽  
Vol 815 ◽  
pp. 69-72
Author(s):  
Jia Jun Si ◽  
Kuan Jun Zhu ◽  
Jian Cheng Wan ◽  
Jia Lun Yang ◽  
Long Liu ◽  
...  
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Simulation Modeling ◽  
Test Method ◽  
Design Stage ◽  
Finite Element Program ◽  
Instability Problem ◽  
Element Simulation ◽  
Element Program ◽  
The Cost

So as to decrease the cost and time of the development, it is significance to solve the section instability problem of diameter-expanded conductor during the design stage. The solution is developing a finite-element simulation program for the study of section stability; however, a proper modeling method is not necessary. In this paper, the parametric study on simulation modeling of diameter-expanded conductor is carried out and through the investigation, analysis and verification; a kind of test method has been designed for the study. After a series of test under different tensions, the numbers of sheave, the position of strand jumping, the section states and the indentation states have been gotten. At last, a parametric finite-element program for strand jumping prediction has been simulated and the result shows that the code developed is reliable based on the comparison of the calculated results and the measured ones.

Finite Element Analysis of Synchronous Belt Tooth Failure

1993 ◽  
Vol 207 (2) ◽  
pp. 145-153 ◽  
Author(s):  
K W Dalgarno ◽  
A J Day ◽  
T H C Childs
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Model ◽  
Element Model ◽  
Element Analysis ◽  
Finite Element Program ◽  
Interface Elements ◽  
Dimensional Finite Element ◽  
Element Program ◽  
Critical Strains

This paper describes a finite element analysis of a synchronous belt tooth under operational loads and conditions with the objective of obtaining a greater understanding of belt failure by tooth root cracking through an examination of the strains within the facing fabric in the belt. The analysis used the ABAQUS finite element program, and was based on a two-dimensional finite element model incorporating a hyperelastic material model for the elastomer compound. Contact between the belt tooth face and the pulley groove was modelled using surface interface elements which allowed only compression and shear forces at the contact surfaces. It is concluded that the critical strains in the facing fabric of the belt, and therefore the belt life, are largely determined by the tangential loading condition on the belt teeth.

Implementation of the Nonlocal Microplane Concrete Model Within an Explicit Dynamic Finite Element Program

1992 ◽  
Vol 45 (3S) ◽  
pp. S132-S139 ◽  
Author(s):  
William F. Cofer
Keyword(s):  
Finite Element ◽  
Strain Tensor ◽  
Material Model ◽  
Material Behavior ◽  
Concrete Material ◽  
Finite Element Program ◽  
Dynamic Finite Element ◽  
Weighted Integral ◽  
Element Program ◽  
Explicit Dynamic

The microplane concrete material model is based upon assumptions regarding the behavior of the material components. At any point, the response to the strain tensor on arbitrarily oriented surfaces is considered. Simple, softening stress-strain relationships are assumed in directions perpendicular and parallel to the surfaces. The macroscopic material behavior is then composed of the sum of the effects. The implementation of this model into the explicit, nonlinear, dynamic finite element program, DYNA3D, is described. To avoid the spurious mesh sensitivity that accompanies material failure, a weighted integral strain averaging approach is used to ensure that softening is nonlocal. This method is shown to be effective for limiting the failure zone in a concrete rod subjected to an impulse loading.

High Speed Impact Characteristics of Plastic Material Based on Finite Element Simulation

2011 ◽  
Vol 383-390 ◽  
pp. 3229-3233 ◽  
Author(s):  
Waluyo Adi Siswanto ◽  
Rodzilla Y. Sharafuddin ◽  
Perowansa Paruka
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Plastic Material ◽  
Strain History ◽  
Finite Element Program ◽  
High Speed Impact ◽  
Element Simulation ◽  
Material Specimen ◽  
Element Program ◽  
As Stress

Testing material specimen on impact using high speed puncture machine can be used to observe the ability of material to withstand under a certain impact speed by looking at the energy required to tear the material. Other detail parameters such as stress, strain and tearing development on impact cannot be seen or measured. This paper presents a finite element method approach to see the strain history and the tearing sequence that cannot be obtained during impact puncture testing of plastic material (Polyethylene Terephthalate / PET). Simulations in different speed; 10 m/s (36 km/h) and 20 m/s (72 km/h) are performed employing a dynamic-explicit Impact finite element program suite. The simulations are able to capture the tearing process, to see the strain histories of tearing region and to predict the tearing pattern. The tearing pattern simulation results are verified by comparing with that from experiment.

FEM Simulation of a Magnetic Shape Memory Foil Actuator Under Different Loading Conditions

2011 ◽  
Author(s):  
B. Krevet ◽  
M. Kohl ◽  
V. Pinneker
Keyword(s):  
Finite Element ◽  
Shape Memory ◽  
Fem Simulation ◽  
Material Model ◽  
Element Model ◽  
Magnetic Shape Memory ◽  
Finite Element Program ◽  
Model And Simulation ◽  
Element Program ◽  
Mechanical Spring

This paper presents a finite element model and simulation results on the performance of a novel linear actuator using the magnetic shape memory (MSM) effect in a Ni-Mn-Ga foil loaded by a mechanical spring. We present finite element simulations with a material model based on the thermodynamic Gibbs free energy in a finite element program (FEM) using beam elements, which is combined with an integral magnetic solver. The simulations qualitatively describe the observed tensile stress-dependence of magneto strain of a first demonstrator of a MSM foil actuator. We demonstrate that complete reversible cycles of the magnetic field induced strain are possible if the spring is preloaded to induce a prestress in the foil. The effect of inhomogeneous material on variant reorientation and corresponding magneto strain are discussed.

Finite element simulation of seismically induced retrogressive failure of submarine slopes

2005 ◽  
Vol 42 (6) ◽  
pp. 1532-1547 ◽  
Author(s):  
A Azizian ◽  
R Popescu
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Soil Mass ◽  
Finite Element Program ◽  
Seismic Liquefaction ◽  
Element Simulation ◽  
Element Program ◽  
Triggering Mechanisms ◽  
Element Removal ◽  
Silt Layer

Retrogressive failures have been reported for both offshore and onshore slopes subjected to various triggering mechanisms. As a result of large spatial extension of the failure, the retrogression phenomenon leads to significantly increasing damage and may affect facilities located far away from the original slope. The mechanisms of such failures are not fully understood, and reports of analyses are rather scarce. To simulate earthquake-induced retrogressive submarine slope failures and to better understand the mechanisms involved, the element removal capabilities of a finite element program are used to model a soil mass that fails and then flows away, causing upper parts of the slope to fail retrogressively, as a result of the loss of support. It is explained how an initial failure leads to subsequent failures of a flat seafloor. Effects of a shallow silt layer and of a gently sloping seafloor on the extension of retrogression in a sandy seabed are also studied. It is found that the extension of failure increases significantly because of a gentle seafloor slope and (or) the presence of a silt layer.Key words: retrogressive submarine failure, seismic liquefaction, finite elements.

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