Finite Element Simulation of Ceramics Machining

2016 ◽  
Vol 693 ◽  
pp. 775-779
Author(s):  
J.X. Xue ◽  
H.B. Wu ◽  
Q.P. Sun

The evolution of crack models based on fracture mechanics is reviewed. The brittle cracking model in Abaqucs is used to simulate the machining process of Al2O3. The result shows that it’s appropriate to simulate the machining process of ceramics with fracture energy cracking criterion and post-failure constitutive relation in a smeared cracking representation. Although more works are needed in the future to resolve the mesh sensitivity. The material removal mechanism of ceramics is confirmed to be the brittle fracture regime.

2012 ◽  
Vol 197 ◽  
pp. 139-143
Author(s):  
Hua Bai ◽  
Yi Du Zhang

The change of ambient temperature will cause deformation during the machining process of large-scale aerospace monolithic component. Based on finite element simulation, thermally induced deformation of reinforcing plate is studied in such aspects as reinforcement structure, clamping method and temperature change, and contact function in finite element software is used to simulate the unilateral constraint between workpiece and worktable. The results indicate that reinforcing plate will produce warping deformation due to the change of ambient temperature. Different reinforcement structures and clamping methods have important influence on the deformation positions and degrees, and the deformation is proportional to the temperature change.


2015 ◽  
Vol 809-810 ◽  
pp. 309-314
Author(s):  
Daniel Ghiculescu ◽  
Nicolae Marinescu ◽  
Tomasz Klepka ◽  
Nicoleta Carutasu

The paper deals with Finite Element Method (FEM) of thermal and mechanical-hydraulic components of material removal mechanism at micro-electrical discharge machining aided by ultrasonics (μEDM+US), due to EDM and US contribution. The dimensions of craters produced by single discharges under μEDM+US conditions are determined with different pulse durations in order to establish a machining strategy with correlation of pulses and tool elongations.


2010 ◽  
Vol 126-128 ◽  
pp. 23-28 ◽  
Author(s):  
Xun Chen ◽  
Tahsin Tecelli Öpöz

The paper presents an investigation of grinding material removal mechanism using finite element method. Understanding of grinding removal mechanism relies on the investigation of material removal by each individual grain. Although some analytical formulations have been developed to predict and to quantify the machining events in grinding, they do not illustrate every stage of abrasive actions. Finite element analysis provides good facility to present details of physical behaviour in grinding. In this research, material removal mechanism of grinding, namely rubbing, ploughing and cutting, is discussed with the variation friction coefficient. The major emphasis here is on the ploughing. Total force variation exerted during indention and sliding of a grain is also presented along its path.


Author(s):  
Chong-Yang Gao ◽  
Liang-Chi Zhang ◽  
Peng-Hui Liu

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.


2014 ◽  
Vol 611-612 ◽  
pp. 1210-1216 ◽  
Author(s):  
Farshid Jafarian ◽  
Mikel Imaz Ciaran ◽  
Pedro José Arrazola ◽  
Luigino Filice ◽  
Domenico Umbrello ◽  
...  

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.


2012 ◽  
Vol 499 ◽  
pp. 208-212
Author(s):  
Ai Hua Gao ◽  
Fu Rong Wang ◽  
Jian Xin Zhang

The paper make the service life of relieving formed milling cutter as the optimization objective, proceed the simulation study on the mechanical degree of cutter, cutting data. The concrete method is that the orthogonal milling model is established to simulate the simulation milling process, some basic parameters which are obtained in the machining process are analyzed and discussed. The results indicate that the finite element simulation of the metal cutting processing can analyze quantitatively some physical properties, such as the cutting force, stress, strain and so on, the traditional way of qualitative analysis is changed. The state of machining is in favour of grasping in the theory, the theory and technology are provided to establish the proper processing technology strategy.


2014 ◽  
Vol 20 (2) ◽  
pp. 159-168 ◽  
Author(s):  
Kazeem K. Adewole ◽  
Steve J. Bull

Steel wires are used as a bridge construction material and as pre-stressing strands or tendons in pre-stressed structural units among other applications in civil engineering. To date, the estimation of the load carrying capacity of a cracked wire has been based on purely experimental classical fracture mechanics work conducted with non-standardised classical fracture mechanics specimens as standard test specimens could not be manufactured from the wire owing to their size. In this work, experimental mechanical tests and finite element simulation with the phenomenological shear fracture model has been conducted to investigate the effect of miniature cracks with dimensions less than or equal to 0.2 mm (which is the limit of the current non-destructive detection technology) on the tensile and fracture properties of flat carbon steel wire. The investigation revealed that the reduction in the displacement at fracture of the wire due to the presence of cracks shallower than 0.2 mm is significantly higher than the reduction in the fracture load of the wire. Consequently, the displacement at fracture and by extension the fracture strain capacity of the wire could serve as a more appropriate parameter to assess the quality and the structural integrity of cracked wires.


2016 ◽  
Vol 836-837 ◽  
pp. 444-451 ◽  
Author(s):  
Long Hui Meng

Finite element simulation of high speed machining of Ti6Al4V alloy was carried out based on the software of Abaqus. The Johnson-Cook constitutive model was chosen for the material of Ti6Al4V, the parameters of the model were obtained through the SHPB (Split Hopkinson Pressure Bar) experiment. The similarity of the chips obtained from the simulation and that obtained from the experiment indicated that the parameters of the Johnson-Cook constitutive model for Ti6Al4V alloy were reliable. Different cutting parameters and different tool geometric parameters were used in the simulations to find out their effects to the simulation results. Also a comparison was made between the results got form the simulations results and the experimental results, a good agreement between them indicated that the finite element simulation of high speed machining of Ti6Al4V is reliable, so it can be concluded that the finite element simulations of high speed machining can be widely used in practice to study the more about the machining process and reduce the experimental expenses.


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