Study on the Residual Stresses Distribution in Thick Pre-Stretched Aluminum Plate

2018 ◽  
Vol 764 ◽  
pp. 49-57
Author(s):  
Hun Guo ◽  
Dun Wen Zuo ◽  
Fei Hong Yin ◽  
Ya Feng He ◽  
Ji Xu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Quantitative Analysis ◽  
Residual Stresses ◽  
Thick Plate ◽  
Engineering Application ◽  
Machining Distortion ◽  
Stress Strain Relation ◽  
Measurement Results ◽  
Aluminum Plates

It is one of the difficult problems in the manufacture of the integrated aircraft part of Machining distortion caused by residual stress. According to the characteristics of aluminum alloy pre stretched thick plate, the modified removal method for measuring residual stress in thick pre-stretched aluminum plates is proposed and the stress-strain relation matrix is deduced by elasticity theory. Moreover, the residual stresses in the specimen of 7075T7351 plate is measured by the proposed method, and the results are finally analyzed and compared with the data obtained by other methods. The results indicate that the proposed method is effective in measuring the residual stress in thick pre-stretched aluminum alloy plates. The measurement results can be used for the quantitative analysis of aerospace parts machining distortion caused by residual stress, and it has higher value in engineering application.

Analysis on the Residual Stresses in the Aluminum Alloy Friction Stir Welded Joints

2011 ◽  
Vol 291-294 ◽  
pp. 958-963
Author(s):  
Li Jie Cao
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Simulation Analysis ◽  
Engineering Application ◽  
Stress Fields ◽  
Weld Strength ◽  
Technological Parameters ◽  
Friction Stir ◽  
Wide Range

The residual stress fields can have strong influences on the integrity and performance of friction stir welded aluminum alloy structure, comprehensive insight into the residual stress distribution is the key to the Friction stir welding (FSW) engineering application for a wide range of materials and thicknesses improving the weld strength and fatigue life. In this paper, the current state of the residual stresses in the FSW aluminum alloy joints is reviewed, The focus is on recent advances of experimental research, the results of numerical simulation analysis, and the effects of the technological parameters(welding speed, rotational speed, shoulder geometry et al.) on residual stress fields was evaluated. In the end, The controlling technique of residual stresses from published literatures is summarized.

Influences of Initial Residual Stresses on Milling Distortion for Thick Aero-Aluminum-Alloy Plate

2011 ◽  
Vol 381 ◽  
pp. 44-47
Author(s):  
Hun Guo ◽  
Dun Wen Zuo ◽  
Guo Xing Tang ◽  
W.M. Gan
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Analytical Method ◽  
Milling Process ◽  
Alloy Plate ◽  
Machining Distortion ◽  
Aluminum Alloy Plate

Formulae of stress re-distribution and distortion by stress releasing during milling process are deduced to Initial Residual Stresses. Theory prediction of milling deformation due to residual stress is finished, and some calculating equation is given for the deformation solution. By means of these researches, the mechanism of the milling deformation due to residual stress is analyzed, the machining distortion caused by residual stress are analyzed and summarized using the analytical method.

Prediction and Measurement of Quenching and Pre-Stretching Stress in 7050 Aluminum Alloy Thick Plate

2021 ◽  
Vol 1026 ◽  
pp. 109-114
Author(s):  
Hai Long Cao ◽  
Jun Qiang Wang ◽  
Yu Xing Tian ◽  
Guan Mei Niu ◽  
Cheng Liu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Simulation Model ◽  
Thick Plate ◽  
Plate Thickness ◽  
Rolling Direction ◽  
Ultrasonic Methods ◽  
7050 Aluminum Alloy ◽  
Direction Component

The article established a modelling that predicted and measured the quenching and pre-stretching stress in 7050 aluminum alloy thick plate in order to make the alloy suitable enough for manufacturing in the aerospace industries. The results show that both the rolling direction component stress and the transverse direction component stress have a “M” distribution along the plate thickness of 7050 aluminum alloy thick plate, but the level is slightly different, but the level is slightly different. The maximum value of quenching residual stress is about 187MPa in the 80mm thick of 7050 plate. Pre-stretching of the heat treated and quenched alloy to 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0% and 3.5% to reduce the residual stresses. It has been recorded that more than 90% reduction of residual stresses were observed in a pre-stretching rage of 2-3%. Measuring the surface residual stresses of the alloy by ultrasonic methods and measuring the internal residual stresses of the alloy by crack compliance methods. The two methods are used to verify the model. The difference between the measurement and the simulation is within 40MPa. The experimental data of the ultrasonic and the crack compliance methods were found to correspond well with the simulated models. This shows that the simulation model can effectively predict the evolution of residual stress in 7050 aluminum alloy thick plate, and the simulation model can also be reconstructed and inspected through the experimentally measurement.

The Applications of Vibratory Stress Relief in High-Strength Aluminum Alloy Thick Plate

2012 ◽  
Vol 430-432 ◽  
pp. 881-885
Author(s):  
Cai Jun Gan ◽  
Kai Liao
Keyword(s):  
Aluminum Alloy ◽  
Residual Stresses ◽  
Dimensional Stability ◽  
Strain Energy ◽  
Thick Plate ◽  
High Strength ◽  
Stress Relief ◽  
High Strength Aluminum Alloy ◽  
Mechanical Stretching ◽  
Stretching Process

The level and distribution of residual stresses have great impact on dimensional stability, while Vibratory Stress Relief (VSR) is an effective technology to relax or homogenize residual stresses. Experimental study on residual stresses distribution, residual strain energy and machining deformation of 7075 high-strength aluminum alloy thick plate under different aging process status shows that VSR can effectively decrease the amplitude and strain energy density, and enhance stability of dislocation structures and phase states in metal microscopic volume, then internal residual stresses are homogenized to enhance components’ anti-deformation capacity. In addition, the capability in maintaining dimensional stability from VSR is better than that from traditional mechanical stretching process

Residual Stresses due to Deep-Drawing of Pre-Coated Aluminum-Alloy Sheets

2005 ◽  
Vol 490-491 ◽  
pp. 358-363 ◽  
Author(s):  
Masatoshi Sudo ◽  
Tomohiko Iwase ◽  
Yoshiyuki Hattori ◽  
Madoka Nakajima
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Sheet Metal ◽  
Direct Contact ◽  
Volatile Oil ◽  
The Press ◽  
The Face ◽  
Coated Layer ◽  
Press Formability

In this study, we examined how the press formability of A1 alloys sheets and the generation of residual stresses was influenced by pre-coating resins, lubricants, die shoulder radius, the punch shoulder radius, and so on. The use of a pre-coated layer offers advantages by preventing direct contact between sheet metal and the face of the die, and also by enabling the use of volatile oil lubricants that keep the factory environment cleaner. The circumferential residual stress (σC ) of a cup becomes lower when the lubricant is less effective, and when the die shoulder radius is smaller.

Finite Element Analysis for Comprehensive Residual Stress of 7075 Aluminum Alloy Thick Plate

2010 ◽  
Vol 154-155 ◽  
pp. 1255-1261
Author(s):  
Hai Yan Li ◽  
Yi Du Zhang ◽  
Hong Wei Zhang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Thick Plate ◽  
Coupling Effect ◽  
Element Model ◽  
Forming Process ◽  
Element Analysis ◽  
Field Coupling ◽  
Simulation And Experiment

Based on “physical field coupling” finite element method, the generation of residual stress and interactive coupling effect were analyzed during the forming process of aluminum alloy thick-plate. Therefore, comprehensive residual stress generated from rolling, quenching and stretching was obtained. The finite element model was proved effective by comparing the results of simulation and experiment. Results show that percent reduction has significant influence to the distribution and magnitude of rolling stress; There is a coupling effect between rolling stress and quenching stress, which represents a basic state; Furthermore, after stretching the distribution of coupling stress remains, but the value reduces greatly; The residual stress has got the minimum, when stretching is near 3%.

XRD Residual Stress and Texture Analysis on 6082T Aluminum Alloy

2021 ◽  
Vol 1028 ◽  
pp. 409-414
Author(s):  
Maykel Manawan ◽  
Sovian Aritonang ◽  
Mas Ayu Elita Hafizah ◽  
Antonius Suban Hali ◽  
Nono Darsono ◽  
...  
Keyword(s):  
Residual Stress ◽  
Shear Stress ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Stress Analysis ◽  
Texture Analysis ◽  
Transverse Direction ◽  
Rolling Direction ◽  
Residual Stress Analysis

The determination of residual stresses is of great importance for many threated metal applications. In this work, the XRD residual stress analysis was used to characterized tempered aluminum-based specimen 6082T with rotation angles (phi) 0°, 45° and 90°, respectively. Highest stress levels were found in the rolling direction (phi = 0°), while negligible along transfers direction (phi = 90°). In addition, a shear stress along rolling and transverse direction, and also the present of texture along (110) can be observed.

Influence of Initial Temperature of Chilling Treatment on Residual Stress State of TIG Dressing Zone for T-Joint Welded Toe

2012 ◽  
Vol 268-270 ◽  
pp. 529-533
Author(s):  
Chun Yuan Shi ◽  
Ping Zhu ◽  
Kun Zhou
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Initial Temperature ◽  
Residual Stress Distribution ◽  
Residual Stress State ◽  
Significant Change ◽  
Chilling Treatment

Using finite element method, the residual stress distribution of TIG dressed welded toe followed by chilling treatment with different temperature of steel and aluminum alloy T-joint was calculated. And the residual stresses of welded toe were also measured by using the blind-hole method. The results indicate that with the increase of initial temperature of chilling treatment, the longitudinal residual stresses in welded toe of steel joint are gradually transited from tensile residual stresses to compressive ones, and there is no significant change for transverse residual stresses; and the longitudinal residual stresses in welded toe of aluminum alloy joint are compressive stress and gradually increased, no significant change for transverse residual stresses.

Influence of Deep Rolling Process Parameters on Surface Residual Stress of AA7075-T651 Aluminum Alloy Friction Stir Welded Joint

2018 ◽  
Vol 939 ◽  
pp. 23-30 ◽  
Author(s):  
Adirek Baisukhan ◽  
Wasawat Nakkiew
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Compressive Residual Stress ◽  
Welded Joint ◽  
Rolling Process ◽  
Rolling Speed ◽  
Deep Rolling ◽  
Friction Stir ◽  
Rolling Pressure

Friction stir welding is most commonly used for joining aluminum alloy parts. After welding, residual stresses occurred in the welded joint caused by non-uniform cooling rate. Friction stir welding usually generates tensile residual stress inside the workpiece which affects the strength in addition to the fatigue life of materials. Compressive residual stress usually is beneficial and it can be introduced by mechanical surface treatment methods such as deep rolling, shot peening, laser shock peening, etc. In this research, deep rolling was used for inducing compressive residual stress on surface of friction stir welded joint. The residual stresses values were obtained from X-ray diffraction machine. Influence of three deep rolling process parameters: rolling pressure, rolling speed and rolling offset on surface residual stresses at the welded joint were investigated. Each factor had 2 levels (23 full factorial design). The statistical analysis result showed that the rolling pressure, rolling speed, rolling offset, interaction between rolling pressure and rolling speed, interaction between rolling speed and rolling offset were statistically significant factors, with the most compressive residual stress value approximately -391.6 MPa. The appropriated deep rolling process parameters on surface residual stress of AA7075-T651 aluminum alloy friction stir welded joint were 1) rolling pressure about 150 bar 2) rolling speed about 1,400 mm/min 3) rolling offset about 0.1 mm.

Residual Stress Analysis in Quenched Aluminum Alloy Plate Using the Contour Method

2016 ◽  
Vol 850 ◽  
pp. 167-174 ◽  
Author(s):  
Ya Nan Li ◽  
Yong An Zhang ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
Guo Jun Wang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Tensile Stress ◽  
Residual Stresses ◽  
Experimental Measurement ◽  
Fem Simulation ◽  
Finite Element Method Simulation ◽  
Maximum Tensile Stress ◽  
Contour Method ◽  
Alloy Plate

A plate (30mm thick) of aluminum alloy 7085-T76 was quenched into water at room temperature after solution treated at 470°C. The quenching residual stresses distributions were studied by both experimental measurement and FEM (Finite Element Method) simulation. The experimental measurement was accomplished by using the contour method, and the FEM simulation was carried out to verify the experimental results. The experimental quenching residual stress distributions showed the tensile stresses of 74.8MPa ~109MPa in the center part, and compressive stresses of 29MPa-63.6MPa on the surface. The prediction distributions showed the maximum tensile stress of 98.2MPa in the center and the maximum compressive stress of 50.5MPa on the surface. The experimental quenching residual stresses distributions agree favorably with the prediction results. The deviations of the maximum tensile stress were less than 25MPa in the center. The deviations may be attributed to the accuracy of the contour method and the idealization of the prediction model.

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