A Wet Etching Method Coupled With Finite Element Analysis-Based Compliance Function to Determine Residual Stress in High-Speed Milling

2006 ◽  
Vol 128 (3) ◽  
pp. 792-801 ◽  
Author(s):  
Y. B. Guo ◽  
S. C. Ammula ◽  
M. E. Barkey

High-speed milling (HSM) is widely used in the automotive and aerospace industries in fabricating mechanical components. HSM induced residual stress may significantly impact fatigue life and the corrosion resistance of machined components. Traditional methods of residual stress measurement are very time consuming and expensive. In this paper we presents a wet etching approach to obtain strain as a function of slot depth introduced in the subsurface. The strain readings were collected from a strain gauge mounted on the specimen surface near the slot edge. A compliance function can be conveniently calculated by simulating slot cutting using a finite element method via a Legendre polynomial subroutine as the applied load. The calculated compliance functions and measured strain values at different depths were used as inputs into a program to calculate residual stress. This leads to a faster and less expensive method of determining residual stress when compared with the traditional methods. The capability of this new approach was demonstrated by high-speed milling 6061-T651 and 7050-T7451 aluminum alloys. A design-of-experiment method was used to conduct milling tests with three levels of cutting speed, feed rate, and DOC. Residual stress profiles with 12 data points with the spatial resolution as small as 1μm in the subsurface were then obtained. Residual stress sensitivity to cutting conditions was investigated. In addition, subsurface microstructure and microhardness were also measured to characterize surface integrity in a broad sense.

Author(s):  
S. C. Ammula ◽  
Y. B. Guo ◽  
M. E. Barkey

High speed milling (HSM) is widely used in automotive and aerospace industries in fabricating mechanical components from high strength aluminum and other alloys due to high productivity and good surface finish. HSM induced residual stresses may significantly impact the fatigue life and corrosion resistance of the machined components. Traditional methods of residual stress (RS) measurement, such as hole drilling, X-ray diffraction, and neutron diffraction, are very time consuming and expensive, especially for the shallow subsurface (usually <100 μm) of a machined component. The compliance method provides a convenient alternative to these approaches to determine the residual stress distributions in the subsurface. However, the compliance method using wire EDM is prone to experimental errors. In addition, the traditional approach to calculate compliance function is very complex. This paper presents a new wet etching approach to obtain strains as a function of slot depth introduced in the subsurface. The strain readings were collected from a strain gauge mounted on the specimen surface near the slot edge. The compliance function can be conveniently calculated by simulating slot cutting using the finite element method via a Legendre polynomial subroutine as the applied load. These calculated compliance functions and measured strain values at different depths were used as inputs into a program to calculate residual stress. This leads to much a faster and less expensive method of determining residual stresses when compared with the traditional methods of residual stress determination. The capability of this new approach was demonstrated by high speed milling 6061-T651 and 7050-T7451 aluminum alloys. A design of experiment (DOE) method was adopted to conduct fifty-four cutting conditions with three levels of cutting speed, feed rate, and depth of cut. Residual stress profiles with twelve data points with spatial resolution as small as 1 μm in the subsurface were then obtained using this new approach. Residual stress sensitivity to cutting conditions was investigated. In addition, subsurface microstructure and microhardness were characterized.


2011 ◽  
Vol 399-401 ◽  
pp. 1806-1811
Author(s):  
Yong Hong Chen ◽  
Peng Chen ◽  
Ai Qin Tian

The finite element model of the roof of aluminum high-speed train was established, double ellipsoid heat source was employed, and heat elastic-plastic theory was used to simulate welding residual stress of the component under different welding sequence based on the finite element analysis software SYSWELD. The distribution law of welding residual stress was obtained. And the effects of the welding sequence on the value and distribution of residual stress was analyzed. The numerical results showed that the simulation data agree well with experimental test data. The maximum residual stress appears in the weld seam and nearby. The residual stress value decreases far away from the welding center. Welding sequence has a significant impact on the final welding residual stress when welding the roof of aluminum body. The side whose residual stress needs to be controlled should be welded first.


2006 ◽  
Vol 524-525 ◽  
pp. 549-554 ◽  
Author(s):  
W.R. Mabe ◽  
W.J. Koller ◽  
A.M. Holloway ◽  
P.R. Stukenborg

This paper presents the results of an experimental validation of the deep hole drill residual stress measurement method. A validation test specimen was fabricated and plastically loaded to impose a permanent residual stress field within the specimen. The validation test specimen was designed to provide a variety of stress profiles as a function of location within the specimen. A finite element analysis of the validation test specimen was performed in order to provide a reference solution for comparison to the deep hole drill experimental results. Results from experimental testing of the validation test specimen agree well with the finite element analysis reference solution, thereby providing further validation of the deep hole drill method to measure residual stresses.


2014 ◽  
Vol 800-801 ◽  
pp. 290-295
Author(s):  
Chuang Liu ◽  
Shu Tao Huang ◽  
Ke Ru Jiao ◽  
Li Fu Xu

Application prospect of the high volume fraction SiCp/Al composites becomes increasingly widespread, the study of cutting mechanism is important for achieving its high efficient and precision machining. In this paper, a three-dimensional beveled simulation model of high volume fraction SiCp/Al composites on high-speed milling is established by finite element software ABAQUS, the constitutive on model material, the tool-chip contact and the chip separation model is elected reasonably.The paper analyzes the effect of cutting speed on the chip formation and the stress distribution of the material. The results shows that: with the increasing of cutting speed, the chip is easily broken, cutting speed have little impact on the maximum stress of the material.


Author(s):  
S. K. Bate ◽  
A. P. Warren ◽  
C. T. Watson ◽  
P. Hurrell ◽  
J. A. Francis

A long-term UK research programme on residual stresses was launched in 2004. It involves Rolls-Royce plc and Serco Assurance, and is supported by UK industry and academia. The programme is aimed at progressing the understanding of weld residual stresses and the implementation of finite element simulation and residual stress measurement for assessing the integrity of engineering structures. Following on from this, the intention is then to develop improved guidance on residual stress modelling techniques. In the first two years finite element activities have addressed heat source representation, simplified modelling (e.g. 2D v 3D, bead lumping), material hardening models, high temperature behaviour and phase transformations. It is recognized that simplifying assumptions have to be made in order to reduce the computational run-time and modelling complexity, especially for multi-pass welds. The effects of these assumptions on the determined stresses have been considered by carrying out finite element analyses of welded mock-ups. The welded mock-ups have been developed to provide measured residual stress data which are necessary to validate the modelling techniques that have been developed. These activities have been used to support the development of guidelines on the use finite element analysis to predict residual stresses in welded components. These guidelines will be incorporated in the next issue of the British Energy R6 defect assessment procedure.


Author(s):  
Avik Samanta ◽  
Mahesh Teli ◽  
Ramesh Singh

Laser-assisted mechanical micromachining offers the ability to machine difficult-to-cut materials, like superalloys and ceramics, more efficiently and economically by laser-induced localized thermal softening prior to cutting. Laser-assisted mechanical micromachining is a micromachining process with localized laser heating which could affect the cutting forces and the machined surface integrity. The residual stresses obtained in the laser-assisted mechanical micromachining process depend on both mechanical loading and the laser heating. This article focuses on the experimental process characterization and prediction of the cutting forces and the residual stresses in a laser-assisted mechanical micromachining–based orthogonal machining of Inconel 625. The results show that the laser assistance reduces the mean cutting forces by ∼25% and enhances the normal compressive residual stress at the surface by ∼50%. Since microscale residual stress measurement is very time-intensive, a coupled-field thermo-mechanical finite element model of laser-assisted mechanical micromachining has been developed to predict the temperature, cutting forces and the residual stresses. The cutting forces and residual stresses’ predictions are in good agreement with the measured values during machining. In addition, parametric simulations have been carried out for laser power, cutting speed, cutting edge radius, rake angle, laser location and laser beam diameter to study their effect on cutting forces and surface residual stresses.


2011 ◽  
Vol 188 ◽  
pp. 216-219 ◽  
Author(s):  
M.H. Wang ◽  
Zhong Hai Liu ◽  
Hu Jun Wang

In order to improve machined surface quality and reduce the deformation, the residual stress involved in cutting titanium alloy was studied under different cutting speed and cutting depth by finite element simulation method. The results indicate that the increase of cutting speed and cutting depth are helpful to the surface residual compressive stress generating. However the increase of cutting speed also leads to the increase of surface residual tensile stress, the effect degree is relatively small. It is required to select higher cutting speed and smaller cutting depth to improve the surface stress state and reduce the unexpected distortion.


2006 ◽  
Vol 532-533 ◽  
pp. 845-848
Author(s):  
Yu Wang ◽  
Fu Gang Yan ◽  
Jing Shu Hu ◽  
Tao Chen ◽  
Zhen Chang ◽  
...  

In this study, hard turning GCr15 bearing steel with high cutting speed is experimental investigated the influence of the CB7015WH insert with chamfer edge and Safe-Lock and the CB7015 insert with a combination of hone radius and a chamfer edge on cutting forces and surface roughness of machined surface. Experimental results show that the cutting forces of the chamfer edge and Safe-Lock is smaller than that of the combination of hone radius and a chamfer edge. Moreover, surface roughness of machined surface with the CB7015WH insert is better. A coupled thermo-mechanical 2D finite element model with general finite element analysis software Deform 2D.8.1 is developed for the influence of two kinds of inserts on cutting forces and effective stress. The simulation results are compared with experimental data and found to be in good agreement.


2012 ◽  
Vol 500 ◽  
pp. 157-162 ◽  
Author(s):  
Zeng Hui Jiang ◽  
Xiao Liang Wang ◽  
Jian Hai Zhang ◽  
Xiao Ye Deng

Due to the complex structures of aviation products made of titanium alloy TC4, residual stress can be generated by the high speed cutting process at their surface which has an important influence on their fatigue strength and also service life. Therefore, in this paper, a 3D finite element model is built to analyze the cutting process with different tool parameters and to investigate the residual stress inside the processed surface. By the numerical study, when the cutting speed is 140 m/min, the residual tensile stress can be generated in the inner cutting surface, while the compressive residual stress in the outer cutting surface. Residual compressive stress can be enhanced by choosing the smaller tool rake angle, the bigger tool relief angle and the bigger cutting edge radius properly.


Sign in / Sign up

Export Citation Format

Share Document