Finite Element Modeling of Random Multiphase Materials for Micromachining

2007 ◽  
Author(s):  
Y. B. Guo ◽  
S. Anurag
Keyword(s):  
Finite Element ◽  
Internal State ◽  
Chip Morphology ◽  
Depth Of Cut ◽  
Element Analysis ◽  
Multiphase Materials ◽  
State Variable ◽  
Dynamic Mechanical Behavior ◽  
Random Microstructure ◽  
Micro Features

Compared with lithographic techniques, mechanical micromachining is a potential competitive process for fabricating 3D micro/meso components or macro parts with micro-features from diverse materials at high accuracy, efficiency, and low costs, but the size effect induced by the comparable size of microstructures, cutting edge radius, and depth-of-cut results in a plowing dominated process. A methodology to incorporate model random microstructure in finite element analysis (FEA) of micromachining multiphase materials has been developed to understand the plowing, tribological, and heat transfer mechanisms. An internal state variable plasticity model has been developed to model the dynamic mechanical behavior including the effect of randomly distributed microstructure, materials damage and evolution. The simulated process variables including chip morphology, forces, and temperatures agree well with the observed experimental phenomena. The simulation recovers the shearing-plowing transition and increased specific energy in micromachining.

Finite Element Analysis of Orthogonal Hard Turning with Different Tool Geometries

2013 ◽  
Vol 581 ◽  
pp. 163-168 ◽  
Author(s):  
Balázs Zsolt Farkas
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Hard Turning ◽  
Cutting Tool ◽  
Chip Morphology ◽  
Depth Of Cut ◽  
Element Analysis ◽  
Wear Process ◽  
The Finite Element Analysis ◽  
Temperature Development

The finite element analysis of hard turning is a strongly investigated research topic thanks to the possible result of the simulations related to the chip morphology, tool wear process, cutting forces etc. The high precision hard turning differs from the conventional hard turning in the view of the depth of cut and feed rate. At low chip volumes, the rigidity of machine and clamping, the geometry of cutting tool play an important role. This research aims to investigate the stress and temperature development of different edge preparations by finite element method.

Finite Element Analysis of a Frictionally Damped Slender Endmill

2012 ◽  
Author(s):  
Reza Madoliat ◽  
Sajad Hayati
Keyword(s):  
Finite Element ◽  
End Milling ◽  
Friction Stress ◽  
Milling Process ◽  
Machining Process ◽  
Depth Of Cut ◽  
Parameter Study ◽  
Bending Vibration ◽  
Element Analysis ◽  
Tool Axis

This paper primarily deals with suppression of chatter in end-milling process. Improving the damping is one way to achieve higher stability for machining process. For this purpose a damper is proposed that is composed of a core and a multi fingered hollow cylinder which are shrink fitted in each other and their combination is shrink fitted inside an axial hole along the tool axis. This structure causes a resisting friction stress during bending vibration. Using FEA-ANSYS the structure is simulated. Then a parameter study is carried out where the frequency response and the depth of cut are calculated and tabulated to obtain the most effective configuration. The optimal configuration of tool is fabricated and finite element results are validated using modal test. The results show a high improvement in performance of the tool with proposed damper. Good agreement between experiments and modeling is obtained.

scholarly journals Finite Element Analysis of Self-Pierce Riveting in Magnesium Alloys Sheets

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
J. F. C. Moraes ◽  
J. B. Jordon ◽  
D. J. Bammann
Keyword(s):  
Magnesium Alloys ◽  
Internal State ◽  
Material Model ◽  
Process Conditions ◽  
Temperature Dependent ◽  
Element Analysis ◽  
State Variable ◽  
Simulation Techniques ◽  
Lightweight Metals ◽  
Joining Process

Conventional fusion joining methods, such as resistance spot welding (RSW), have been demonstrated to be ineffective for magnesium alloys. However, self-pierce riveting (SPR) has recently been shown as an attractive joining technique for lightweight metals, including magnesium alloys. While the SPR joining process has been experimentally established on magnesium alloys through trial and error, this joining process is not fully developed. As such, in this work, we explore simulation techniques for modeling the SPR process that could be used to optimize this joining method for magnesium alloys. Due to the process conditions needed to rivet the magnesium sheets, high strain rates and adiabatic heat generation are developed that require a robust material model. Thus, we employ an internal state variable (ISV) plasticity material model that captures strain-rate and temperature dependent deformation. In addition, we explore various damage modeling techniques needed to capture the piercing process observed in the joining of magnesium alloys. The simulations were performed using a two-dimensional axisymmetric model with various element deletion criterions resulting in good agreement with experimental data. The simulations results of this study show that the ISV material model is ideally suited for capturing the complex physics of the plasticity and damage observed in the SPR of magnesium alloys.

Complex Modal Analysis of a Nonmodally Damped Continuous Beam

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Xing Xing ◽  
Brian F. Feeny
Keyword(s):  
Finite Element ◽  
Eigenvalue Problem ◽  
Normal Modes ◽  
Damping Coefficient ◽  
Mode Analysis ◽  
Element Analysis ◽  
Assumed Mode Method ◽  
State Variable ◽  
Complex Modes ◽  
Assumed Mode

This work represents an investigation of the complex modes of continuous vibration systems with nonmodal damping. As an example, a cantilevered beam with damping at the free end is studied. Assumed modes are applied to discretize the eigenvalue problem in state-variable form and then to obtain estimates of the true complex normal modes and frequencies. The finite element method (FEM) is also used to get the mass, stiffness, and damping matrices and further to solve a state-variable eigenvalue problem. A comparison between the complex modes and eigenvalues obtained from the assumed-mode analysis and the finite element analysis shows that the methods produce consistent results. The convergence behavior when using different assumed mode functions is investigated. The assumed-mode method is then used to study the effects of the end-damping coefficient on the estimated normal modes and modal damping. Most modes remain underdamped regardless of the end-damping coefficient. There is an optimal end-damping coefficient for vibration decay, which correlates with the maximum modal nonsynchronicity.

Finite Element Analysis of the Effect of Cutting Speed on the Orthogonal Turning of A359/SiCp MMC

2016 ◽  
Vol 852 ◽  
pp. 304-310
Author(s):  
M.M. Thamizharasan ◽  
Y.J. Nithiya Sandhiya ◽  
K.S. Vijay Sekar ◽  
V.V. Bhanu Prasad
Keyword(s):  
Finite Element ◽  
Matrix Material ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Fe Model ◽  
Element Analysis ◽  
Damage And Fracture ◽  
Orthogonal Turning ◽  
The Matrix ◽  
Cutting Speeds

The application of Metal Matrix Composite (MMC) has been increasing due to its superior strength and wear characteristics but the major challenge is its poor machinability due to the presence of reinforcement in the matrix which is a hindrance during machining. The material behaviour during machining varies with respect to input variables. In this paper the effect of cutting speed during the orthogonal turning of A359/SiCp MMC with TiAlN tool insert is analysed by developing a 2D Finite Element (FE) model in Abaqus FEA code. The FE model is based on plane strain formulation and the element type used is coupled temperature displacement. The matrix material is modeled using Johnson–Cook (J-C) thermal elastic–plastic constitutive equation and chip separation is simulated using Johnson–Cook’s model for progressive damage and fracture with parting line. Particle material is considered to be perfectly elastic until brittle fracture. The tool is considered to be rigid. The FE model analyses the tool interaction with the MMC and its subsequent effects on cutting forces for different cutting speeds and feed rates. The chip formation and stress distribution are also studied. The FE results are validated with the experimental results at cutting speeds ranging from 72 – 188 m/min and feed rates ranging from 0.111 – 0.446 mm/rev at constant depth of cut of 0.5mm.

scholarly journals FEM-based comparative study of SQUARE & RHOMBIC INSERT machining performance during turning of AISI-D3 steel

2021 ◽  
Vol 13 (2) ◽  
pp. 143-148
Author(s):  
Anastasios Tzotzis ◽  
◽  
Nikolaos Efkolidis ◽  
Gheorghe Oancea ◽  
Panagiotis Kyratsis ◽  
...  
Keyword(s):  
Finite Element ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
The Finite Element Method ◽  
Machining Simulation ◽  
Machining Performance ◽  
Machining Processes ◽  
Element Analysis ◽  
Friction Forces ◽  
Aisi D3 Steel

Nowadays, employment of the Finite Element Method (FEM) in machining simulation is a common practice to decrease development times and costs, as well as to investigate numerous parameters that affect machining processes. In the present work, the 3D modelling of AISI-D3 hard turning with both square and rhombic inserts is being presented by utilizing a commercially available Finite Element Analysis (FEA) software. Eighteen tests were carried out based on cutting conditions that are recommended for the used tools. Specifically, three levels of cutting speed (75m/min, 110m/min and 140m/min), three levels of feed (0.12mm/rev, 0.16mm/rev and 0.20mm/rev) and depth of cut equal to 0.40mm for all tests, were applied. In order to describe the complex factors that define the model, such as the friction forces, the heat transfer and the pressure due to contact between the tool and the workpiece, a number of acknowledged models were utilized. A comparison of the performance between the two types of tools was made with respect to the developed machining forces and temperature distribution on the workpiece. The findings of the investigation indicate that the specific square tools produce higher values of forces compared to the rhombic ones and approximately the same temperature patterns on the workpiece. The average increase on the produced cutting forces is about 26.4%.

Finite element analysis of strain localization in multiphase materials

2005 ◽  
Vol 9 (5-6) ◽  
pp. 767-778
Author(s):  
Lorenzo Sanavia ◽  
Franceso Pesavento ◽  
Bernhard A Schrefler
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Localization ◽  
Element Analysis ◽  
Multiphase Materials

Mesoscale Simulation-based Parametric Study of Damage Potential in Brain Tissue Using Hyperelastic and Internal State Variable Models

2021 ◽  
Author(s):  
Ge He ◽  
Lei Fan ◽  
Yucheng Liu
Keyword(s):  
Finite Element ◽  
Brain Tissue ◽  
Internal State ◽  
Stress Triaxiality ◽  
Local Maximum ◽  
Internal State Variable ◽  
State Variable ◽  
Brain Lobe ◽  
Von Mises ◽  
The Brain

Abstract Two-dimensional mesoscale finite element analysis (FEA) of a multi-layered brain tissue was performed to calculate the damage related average stress triaxiality and local maximum von Mises strain in the brain. The FEA was integrated with rate dependent hyperelastic and internal state variable (ISV) models respectively describing the behaviors of wet and dry brain tissues. Using the finite element results, a statistical method of design of experiments (DOE) was utilized to independently screen the relative influences of seven parameters related to brain morphology (sulcal width/depth, gray matter (GM) thickness, cerebrospinal fluid (CSF) thickness and brain lobe) and loading/environment conditions (strain rate and humidity) with respect to the potential damage growth/coalescence in the brain tissue. The results of the parametric study illustrated that the GM thickness and humidity were the two most crucial parameters affecting average stress triaxiality. For the local maximum von Mises strain at the depth of brain sulci, the brain lobe/region was the most influential factor. The conclusion of this investigation gives insight for the future development and refinement of a macroscale brain damage model incorporating information from lower length scale

Finite element analysis of strain localization in multiphase materials

2005 ◽  
Vol 9 (5-6) ◽  
pp. 767-778 ◽  
Author(s):  
Lorenzo Sanavia ◽  
Francesco Pesavento ◽  
Bernhard A. Schrefler
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Localization ◽  
Element Analysis ◽  
Multiphase Materials
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