Research on the 5-axis Machining of Blisk

2006 ◽  
Vol 532-533 ◽  
pp. 612-615 ◽  
Author(s):  
Chuang Guo Hu ◽  
Ding Hua Zhang ◽  
Jun Xue Ren ◽  
Lei Yang
Keyword(s):  
Residual Stresses ◽  
Double Point ◽  
New Method ◽  
Freeform Surface ◽  
Boundary Contour ◽  
Tool Paths ◽  
Tool Axis ◽  
Part Distortion ◽  
Thin Walled ◽  
Axis Drive

The study presents a new method for 5-axis machining of blisk, which consists of both roughing tunnels and finishing blades. The ruled surface is used to approximate the freeform surface of blade, and the boundary contour of the tunnel is then determined. Based on the double point offset method, the 5-axis tool paths for roughing blisk tunnel region are generated. Similarly, by linking the corresponding points on the tool center curves and the tool axis drive curves, the spiral tool paths are developed to finish milling thin-walled blades taking into account the residual stresses induced part distortion during machining. This strategy is experimentally verified.

Concept to analyze residual stresses in milled thin walled monolithic aluminum components and their effect on part distortion

2019 ◽  
pp. 287-296 ◽  
Author(s):  
Daniel Weber ◽  
Benjamin Kirsch ◽  
Christopher R. D’Elia ◽  
Barbara S. Linke ◽  
Michael R. Hill ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Part Distortion ◽  
Thin Walled

Study on the Generation and Redistribution Mechanism of Residual Stress in Bilateral Rolling Correction Process for Thin-Walled Parts

2017 ◽  
Author(s):  
Laixiao Lu ◽  
Jie Sun ◽  
Kai Guo ◽  
Jianfeng Li
Keyword(s):  
Plastic Deformation ◽  
Residual Stresses ◽  
True Strain ◽  
High Amplitude ◽  
Rolling Process ◽  
Distortion Correction ◽  
Correction Process ◽  
Redistribution Mechanism ◽  
Part Distortion ◽  
Thin Walled

The distortion and dimensional instability are the main problems in the machining of thin-walled parts with high-strength aluminum alloys. To ensure the accuracy of aircraft assembly, distortion correction process is essential. Bilateral rolling process has been widely used to correct the distorted parts in the aerospace industries due to the introduction of proper plastic deformation and residual stresses. However, the generation and redistribution mechanism of residual stresses in bilateral rolling correction process remains unclear. This internal mechanism was investigated by finite element method (FEM) in this paper. First, FE models were verified by experiments in terms of residual stresses and strain. Then, simulation results (e.g. plastic strain, true strain and part distortion) were extracted for further analysis. It was shown that the residual stresses are produced in the compatibility process of plastic and elastic strain, and a large plastic deformation can lead to a high amplitude residual stresses. Besides, the binding force from the surrounding materials also results in higher strain gradient and amplitude of residual stresses. Although part distortion has little effect on the limit value of residual stresses, it greatly influences the redistribution of the residual stresses.

Analysis of circumferentially welded thin-walled cylinders to study the effects of tack weld orientations and joint root opening on residual stress fields

2009 ◽  
Vol 223 (5) ◽  
pp. 1037-1049 ◽  
Author(s):  
N U Dar ◽  
E M Qureshi ◽  
A M Malik ◽  
M M I Hammouda ◽  
R A Azeem
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Arc Welding ◽  
Operating Conditions ◽  
Stress Fields ◽  
Welded Structures ◽  
Prime Concern ◽  
Thin Walled ◽  
Tack Weld ◽  
Welding Processes

In recent years, the demand for resilient welded structures with excellent in-service load-bearing capacity has been growing rapidly. The operating conditions (thermal and/or structural loads) are becoming more stringent, putting immense pressure on welding engineers to secure excellent quality welded structures. The local, non-uniform heating and subsequent cooling during the welding processes cause complex thermal stress—strain fields to develop, which finally leads to residual stresses, distortions, and their adverse consequences. Residual stresses are of prime concern to industries producing weld-integrated structures around the globe because of their obvious potential to cause dimensional instability in welded structures, and contribute to premature fracture/failure along with significant reduction in fatigue strength and in-service performance of welded structures. Arc welding with single or multiple weld runs is an appropriate and cost-effective joining method to produce high-strength structures in these industries. Multi-field interaction in arc welding makes it a complex manufacturing process. A number of geometric and process parameters contribute significant stress levels in arc-welded structures. In the present analysis, parametric studies have been conducted for the effects of a critical geometric parameter (i.e. tack weld) on the corresponding residual stress fields in circumferentially welded thin-walled cylinders. Tack weld offers considerable resistance to the shrinkage, and the orientation and size of tacks can altogether alter stress patterns within the weldments. Hence, a critical analysis for the effects of tack weld orientation is desirable.

scholarly journals Cross-Sectional Mapping of Residual Stresses by Measuring the Surface Contour After a Cut

2000 ◽  
Vol 123 (2) ◽  
pp. 162-168 ◽  
Author(s):  
M. B. Prime
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Superposition Principle ◽  
New Method ◽  
Contour Method ◽  
Stress Profile ◽  
Relaxation Methods ◽  
Cross Sectional ◽  
Residual Stress Profile

A powerful new method for residual stress measurement is presented. A part is cut in two, and the contour, or profile, of the resulting new surface is measured to determine the displacements caused by release of the residual stresses. Analytically, for example using a finite element model, the opposite of the measured contour is applied to the surface as a displacement boundary condition. By Bueckner’s superposition principle, this calculation gives the original residual stresses normal to the plane of the cut. This “contour method” is more powerful than other relaxation methods because it can determine an arbitrary cross-sectional area map of residual stress, yet more simple because the stresses can be determined directly from the data without a tedious inversion technique. The new method is verified with a numerical simulation, then experimentally validated on a steel beam with a known residual stress profile.

A Fast Method for Solving Contact Plasticity in a Half Space

2011 ◽  
Author(s):  
Zhanjiang Wang ◽  
Xiaoqing Jin ◽  
Shuangbiao Liu ◽  
Leon M. Keer ◽  
Jian Cao ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Residual Stresses ◽  
Fast Fourier Transform ◽  
Half Space ◽  
Three Dimensional ◽  
New Method ◽  
Fast Method ◽  
Discrete Convolution ◽  
Influence Coefficients ◽  
The One

This paper presents a new method of contact plasticity analysis based on Galerkin vectors to solve the eigenstresses due to eigenstrain. The influence coefficients relating eigenstrains to eigenstresses thus can be divided into four terms the one due to the eigenstrains in the full space, others due to the mirrored eigenstrains in the mirror half space. Each term can be solved fast and efficient by using the three-dimensional discrete convolution and fast Fourier transform (DC-FFT) or the three-dimensional discrete correlation and fast Fourier transform (DCR-FFT). The new method is used to analyze the contact plastic residual stresses in half space.

Average Residual Stresses in Hard Physical Vapor Deposited (PVD) Coatings

2019 ◽  
Vol 799 ◽  
pp. 20-25
Author(s):  
Harri Lille ◽  
Alexander Ryabchikov ◽  
Jakub Kõo ◽  
Valdek Mikli ◽  
Eron Adoberg ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Front Surface ◽  
Back Surface ◽  
Length Variation ◽  
Pvd Coatings ◽  
Cross Sectional ◽  
Average Residual ◽  
Thin Walled ◽  
Compressive Residual Stresses ◽  
Very High

In this study we determined average residual stresses in hard nitride PVD AlCrN, TiAlN and TiCN coatings through simultaneous measurement of length variation in thin-walled tubular substrates and of the curvature of plate substrates. A device for measurement of the length of the tube was developed. Inside the depositing chamber the tube and the plate were fixed parallel in the relation to the axis of the rotating cathode. One batch of plate samples was produced by deposition on front surface (facing the cathode) and the other batch, by deposition on back surface (with back to the cathode). The cross-sectional microstructure and thickness of the coatings were investigated by means of scanning electron microscopy (SEM). The thicknesses of the coatings deposited on front and back surfaces of the plates and on the tube were significantly different. The values of average compressive residual stresses, determined by both methods, were very high irrespective of coating thickness. It was found that the values of compressive residual stresses in the coating were dependent on the shape of the substrate and on its position in the relation to the axis of the rotating cathode.

The Effect of Quench-Induced Residual Stresses on the Distortion of Machined Thin-Walled Parts

2015 ◽  
Vol 24 (10) ◽  
pp. 3933-3941 ◽  
Author(s):  
Soroush Masoudi ◽  
Ghasem Amirian ◽  
Ehsan Saeedi ◽  
Mohammad Ahmadi
Keyword(s):  
Residual Stresses ◽  
Thin Walled

A New Method for the Generation of Tool Paths for Finishing Near Net Shape Components

2013 ◽  
Author(s):  
Edgar A. Mendoza López ◽  
Hugo I. Medellín Castillo ◽  
Dirk F. de Lange ◽  
Theo Lim
Keyword(s):  
Geometric Modeling ◽  
Tool Path ◽  
Cutting Tools ◽  
Approximation Error ◽  
Cnc Machining ◽  
New Method ◽  
End Mill ◽  
Tool Paths ◽  
Near Net Shape ◽  
Finish Cut

The CNC machining has been one of the most recurrent processes used for finishing NNS components. This paper presents a new method for the generation of tool paths for machining 3D NNS models. The proposed approach comprises two machining stages: rough cut and finish cut, and three types of cutting tools: ball-end mill, flat-end mill and fillet-end mill. The proposed tool path generation algorithm is based on: (1) approximation of the model surfaces by points using slice planes and visibility analysis, (2) accessibility analysis of the tool, (3) approximation error and tolerance evaluation, (4) collision analysis of tool and tool holder. The tools paths generated are exported as a CNC program. The implementation was carried out in C++ using the ACIS® geometric modeling kernel to support the required geometric operations. To prove the effectiveness of the system several models with variable geometric complexity were tested. The results have shown that the proposed system is effective and therefore can be used to generate the tool paths required for finishing 3D NNS components.

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