Effect of constitutive material model on the finite element simulation of shear localization onset

2020 ◽  
Vol 104 ◽  
pp. 102105
Author(s):  
Okan Deniz Yılmaz ◽  
Samad Nadimi Bavil Oliaei
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Material Model ◽  
Shear Localization ◽  
Constitutive Material Model ◽  
Element Simulation ◽  
Constitutive Material

Finite element simulation of fracture toughness testing of 20MnMoNi55 steel and the effect of loading rate on reference temperature

2020 ◽  
pp. 146442072095667
Author(s):  
Swagatam Paul ◽  
Snehasish Bhattacharjee ◽  
Sanjib Kumar Acharyya ◽  
Prasanta Sahoo
Keyword(s):  
Fracture Toughness ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Loading Rate ◽  
Flow Characteristics ◽  
Material Model ◽  
Compact Tension ◽  
Reference Temperature ◽  
Viscoplastic Material ◽  
Element Simulation

Fracture toughness of ferritic steel in the ductile-to-brittle transition zone is scattered and probabilistic owing to embrittlement. Use of master curve along with the reference temperature ( T0) adopted in ASTM E-1921 is widely accepted for characterization of this embrittlement. Reference temperature is a measure of embrittlement in the temperature scale. Factors affecting fracture toughness like geometry and loading rate are expected to influence the reference temperature. In the present study, the role of the loading rate on the reference temperature for 20MnMoNi55 steel is assessed experimentally using compact tension C(T) and three-point bend (TPB) specimens. Finite element simulation of tests at different loading rates and cryogenic temperature are carried out using a suitable viscoplastic material model that incorporates flow characteristics of the material for varying displacement rates and cryogenic temperatures. Results from simulation studies are compared with experimental ones.

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.

The Development of Multi-Directional Spatially Reinforced Material Structural Theory

2018 ◽  
Vol 284 ◽  
pp. 146-151 ◽  
Author(s):  
I.V. Magnitsky ◽  
F.R. Odinabekov ◽  
E.S. Sergeeva
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Elastic Properties ◽  
Simulation Models ◽  
Material Model ◽  
Analytical Models ◽  
Structural Components ◽  
Reinforced Composite ◽  
Element Simulation ◽  
Reinforced Composite Material

Finite-element simulation of the spatially reinforced composite material elastic properties is performed. The simulation models are built in two steps: first, a 4DL-reinforced material model simulating a perfect matrix/rod contact is built; second, an improved simulation model is developed, taking into account the possibility of separation between the composite components. Comparison is made between the results obtained numerically and those based on the existing analytical models. With these finite-element simulation models, it is possible to estimate the required composite elastic properties to be used when designing structural components based on those materials.

Effects of the Flow Stress in Finite Element Simulation of Machining Inconel 718 Alloy

2014 ◽  
Vol 611-612 ◽  
pp. 1210-1216 ◽  
Author(s):  
Farshid Jafarian ◽  
Mikel Imaz Ciaran ◽  
Pedro José Arrazola ◽  
Luigino Filice ◽  
Domenico Umbrello ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Inconel 718 ◽  
Orthogonal Cutting ◽  
Material Model ◽  
Material Behavior ◽  
Machining Process ◽  
Inconel 718 Alloy ◽  
Element Simulation ◽  
Inconel 718 Superalloy

Inconel 718 superalloy is one of the difficult-to-machine materials which is employed widely in aerospace industries because of its superior properties such as heat-resistance, high melting temperature, and maintenance of strength and hardness at high temperatures. Material behavior of the Inconel 718 is an important challenge during finite element simulation of the machining process because of the mentioned properties. In this regard, various constants for Johnson–Cook’s constitutive equation have been reported in the literature. Owing to the fact that simulation of machining process is very sensitive to the material model, in this study the effect of different flow stresses were investigated on outputs of the orthogonal cutting process of Inconel 718 alloy. For each model, the predicted results of cutting forces, chip geometry and temperature were compared with experimental results of the previous work at the different feed rates. After comparing the results of the different models, the most suitable Johnson–Cook’s material model was indentified. Obtained results showed that the selected material model can be used reliably for machining simulation of Inconel 718 superalloy.

Research on Ultrasonic Shot Peening through Numerical Simulation

2015 ◽  
Vol 778 ◽  
pp. 59-62 ◽  
Author(s):  
Yan Jun Fan ◽  
Xiao Hui Zhao
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Shot Peening ◽  
Three Dimensional ◽  
Material Model ◽  
Simulation Method ◽  
Strengthening Mechanism ◽  
Mechanical Parts ◽  
Element Simulation ◽  
Ultrasonic Shot Peening

Ultrasonic shot peening can be used to strengthen mechanical parts. Its equipment structure is compact, which is convenient for incorporated into production line. It is fitting to facilitate operation and high reproducibility without dust pollution and noise. The finite element simulation method of ultrasonic shot peening further contributes to the development of ultrasonic shot peening technology. In the present work, finite element simulation method was adopted to establish a three-dimensional numerical model for analyzing the strengthening mechanism of ultrasonic shot peening. By choosing reasonable material model and different combination of parameters (such as treated material, diameter of shots, peening velocity), the curves of residual stress vs. depth of alloy materials were obtained, including the relationships between the peak value and depth of residual compression stress and peening velocity.

3D pull-out finite element simulation of the pedicle screw-trabecular bone interface at strain rates

2021 ◽  
pp. 095441192110445
Author(s):  
Ahmet Çetin ◽  
Durmuş Ali Bircan
Keyword(s):  
Finite Element ◽  
Strain Rate ◽  
Trabecular Bone ◽  
Finite Element Simulation ◽  
Pedicle Screw ◽  
Material Model ◽  
Strain Rates ◽  
Pull Out ◽  
Element Simulation ◽  
Screw Diameter

Biomedical experimental studies such as pull-out (PO), screw loosening experience variability mechanical properties of fresh bone, legal procedures of cadaver bone samples and time-consuming problems. Finite Element Method (FEM) could overcome experimental problems in biomechanics. However, material modelling of bone is quite difficult, which has viscoelastic and viscoplastic properties. The study presents a bone material model which is constructed at the strain rates with the Johnson-Cook (JC) material model, one of the robust constitutive material models. The JC material constants of trabecular bone are determined by the curve fitting method at strain rates for the 3D PO finite element simulation, which defines the screw-bone interface relationship. The PO simulation is performed using the Abaqus/CAE software program. Bone fracture mechanisms are simulated with dynamic/explicit solutions during the PO phenomenon. The paper exposes whether the strain rate has effects on the PO performance. Moreover, simulation reveals the relationship between pedicle screw diameter and PO performance. The results obtained that the maximum pull-out force (POF) improves as both the screw diameter and the strain rate increase. For 5.5 mm diameter pedicle screw POFs were 487, 517 and 1708 N at strain rate 0.00015, 0.015 and 0.015 s−1, respectively. The FOFs obtained from the simulation of the other screw were 730, 802 and 2008 N at strain rates 0.00015, 0.0015 and 0.015, respectively. PO phenomenon was also simulated realistically in the finite element analysis (FEA).

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