On the Application of Arbitrary Lagrangian-Eulerian and Remeshing Techniques to Simulate Certain Machining and Deformation Processing Operations

Author(s):  
Vandana A. Salilkumar ◽  
Narayan K. Sundaram

Abstract Metal cutting and deformation processing operations provide some of the most challenging problems for modeling and simulation in computational plasticity. These challenges include, but are not limited to, extreme plastic deformation, challenges in constitutive and interfacial friction modeling, microstructural effects, mechanical and thermoplastic instabilities, multiphysics effects due to cutting fluid and high temperatures, and are generally computationally intensive. Despite considerable progress in each of these fronts, there is scope to expand the envelope of simulations that capture the deformation physics while being computationally feasible. Moreover, even conventional standard FEA codes can be leveraged for modeling and simulation in more effective ways. In this work, we present three challenging scenarios for modeling, namely large strain extrusion machining (LSEM), forming using a flat punch, and cutting of inhomogeneous metal, using a mix of Arbitrary Lagrangian Eulerian (ALE), conventional Lagrangian FE, and remeshing techniques. Some of these simulations are ‘standard’, while others are first-in-class, and we discuss both specific and general modeling issues that must be considered to obtain good quality solutions. Specific mechanics insights gleaned from each of these case studies are also presented, ranging from the influence of friction in deep punch indentation to the selection of the chip thickness ratio in LSEM. The last part of this work focuses on problems that arise in the simulation of polycrystalline aggregate cutting, and the progress made in addressing them.

2021 ◽  
Author(s):  
Hui Liu ◽  
Markus Meurer ◽  
Daniel Schraknepper ◽  
Thomas Bergs

Abstract Cutting fluids are an important part of today's metal cutting processes, especially when machining aerospace alloys. They offer the possibility to extend tool life and improve cutting performance. However, the equipment and handling of cutting fluids also raises manufacturing costs. To reduce the negative impact of the high cost of cutting fluids, cooling systems and strategies are constantly being optimized. In most existing works, the influences of different cooling strategies on the relevant process parameters, such as tool wear, cutting forces, chip breakage, etc., are empirically investigated. Due to the limitations of experimental methods, analysis and modeling of the working mechanism has so far only been carried out at a relatively abstract level. For a better understanding of the mechanism of cutting fluids, a thermal coupled two-dimensional simulation approach for the orthogonal cutting process was developed in this work. This approach is based on the Coupled Eulerian Lagrangian (CEL) method and provides a detailed investigation of the cutting fluid’s impact on chip formation and tool temperature. For model validation, cutting tests were conducted on a broaching machine. The simulation resolved the fluid behavior in the cutting area and showed the distribution of convective cooling on the tool surface. This work demonstrates the potential of CEL based cutting fluid simulation, but also pointed out the shortcomings of this method.


Author(s):  
Mitsuru Hasegawa ◽  
Tatsuya Sugihara

Abstract In cutting of Ti-6Al-4V alloy, the cutting speed is limited since a high cutting temperature leads to severe tool wear and short tool life, resulting in poor production efficiency. On the other hand, some recent literature has reported that various beneficial effects can be provided by forming micro-textures on the tool surface in the metal cutting process. In this study, in order to achieve high-performance machining of Ti-6Al-4V, we first investigated the mechanism of the tool failure process for a cemented carbide cutting tool in high-speed turning of Ti-6Al-4V. Based on the results, cutting tools with micro textured surfaces were developed under the consideration of a cutting fluid action. A series of experiments showed that the textured rake face successfully decreases the cutting temperature, resulting in a significant suppression of both crater wear and flank wear. In addition, the temperature zone where the texture tool is effective in terms of the tool life in the Ti-6Al-4V cutting was discussed.


Author(s):  
Shiro Torizuka ◽  
Akio Ohmori ◽  
S.V.S. Narayana Murty ◽  
Kotobu Nagai

Inventions ◽  
2017 ◽  
Vol 2 (4) ◽  
pp. 29 ◽  
Author(s):  
Peter Arrabiyeh ◽  
Martin Bohley ◽  
Felix Ströer ◽  
Benjamin Kirsch ◽  
Jörg Seewig ◽  
...  

1997 ◽  
Vol 119 (1) ◽  
pp. 86-94 ◽  
Author(s):  
D. A. Stephenson ◽  
P. Bandyopadhyay

Obtaining accurate baseline force data is often the critical step in applying machining simulation codes. The accuracy of the baseline cutting data determines the accuracy of simulated results. Moreover, the testing effort required to generate suitable data for new materials determines whether simulation provides a cost or time advantage over trial-and-error testing. The efficiency with which baseline data can be collected is limited by the fact that simulation programs do not use standard force or pressure equations, so that multiple sets of tests must be performed to simulate different machining processes for the same tool-workpiece material combination. Furthermore, many force and pressure equations do not include rake angle effects, so that separate tests are also required for different cutter geometries. This paper describes a unified method for simulating cutting forces in different machining processes from a common set of baseline data. In this method, empirical equations for cutting pressures or forces as a function of the cutting speed, uncut chip thickness, and tool normal rake angle are fit to baseline data from end turning, bar turning, or fly milling tests. Forces in specific processes are then calculated from the empirical equations using geometric transformations. This approach is shown to accurately predict forces in end turning, bar turning, or fly milling tests on five common tool-work material combinations. As an example application, bar turning force data is used to simulate the torque and thrust force in a combined drilling and reaming process. Extrapolation errors and corrections for workpiece hardness variations are also discussed.


2014 ◽  
Vol 660 ◽  
pp. 8-12
Author(s):  
J.B. Saedon ◽  
Noor Aniza Norrdin ◽  
Mohd Azman Yahaya ◽  
N.H. Mohamad Nor ◽  
Mohd Zulhafiz Md Salih

Chip formation is a dynamic process that is often nonlinear in nature. A chip may not form when the depth of cut is less than a minimum chip thickness. It is aimed to investigate influence of depth of cut on contact phenomenon in micromachining. This paper presents a series of simulation works by finite element method on depth of cut effect on micromachining. A model is developed with consideration of the Johnson-Cook material and Arbitrary Lagrangian–Eulerian (ALE) method. In this work investigate the effect of depth of cut on the contact phenomenon during micromachining AISI D2. The results of the analysis are showed in aspects of interrelationship between material separation and frictional shear contact, distribution of stick-slide regions and contact stress on the work piece and cutting tool. It is found that the sticking and sliding was occurred on three zones as primary, secondary and tertiary shear zone. The contact phenomena can be showed around the tool edge radius where material flows around it and piles in front of the cutting tool through material separation. The investigation of contact phenomena inclusive under three criteria such as a/r < 1, a/r > 1 and a/r = 1 on positive rake angle.


2020 ◽  
Vol 4 (2) ◽  
pp. 45 ◽  
Author(s):  
Thomas Lakner ◽  
Marvin Hardt

The tribological effect of cutting fluids in the machining processes to reduce the friction in the cutting zone is still widely unknown. Most test benches and procedures do not represent the contact conditions of machining processes adequately, especially for interrupted contacts. This results in a lack of knowledge of the tribological behavior in machining processes. To close this knowledge gap, a novel experimental test bench to investigate the effects of cutting fluids on the frictional conditions in metal cutting under high-pressure cutting fluid supply was developed and utilized within this work. The results show that there is a difference between the frictional forces in interrupted contact compared to continuous contact. Furthermore, the cutting fluid parameters of supply pressure, volumetric flow rate, and impact point of the cutting fluid jet influence the frictional forces, the intensities of which depend on the workpiece material. In conclusion, the novel test bench allows examining the frictional behavior in interrupted cuts with an unprecedented precision, which contributes to a knowledge-based design of the cutting fluid supply for cutting tools.


Sign in / Sign up

Export Citation Format

Share Document