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.

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.

A Mathematical Model for Predicting Residual Stresses in Pre-Stretched Aluminum Alloy Plate

2010 ◽  
Vol 97-101 ◽  
pp. 3187-3193 ◽  
Author(s):  
Shu Yuan Zhang ◽  
Yun Xin Wu
Keyword(s):  
Mathematical Model ◽  
Residual Stress ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Rolling Direction ◽  
Stress Relief ◽  
Published Data ◽  
Alloy Plate ◽  
Stress Theory ◽  
Aluminum Alloy Plate

A mathematical model has been developed to predict the residual stresses level in pre-stretched aluminum alloy plate. This is based on force balances of the residual stress, theory of plastoelasticity and a new conception of free length. The model is relatively simple because only rolling direction residual stress is taken into account, but provides a clear illustration of stress relief mechanism in stretching process. With this model, residual stress distributions of stretched beam can be determined directly by knowing the specimen dimensions, material properties and the original stress. The model offers an useful tool to show the effect of varying tension ratio on the final residual stress level, thus makes it possible to predict stress relief and control residual stresses. An example of using the model is presented by applying published data while showing mechanism of stress relief during stretching. Analysis indicates that it is stretch-caused convergence of the free lengths of strips in beam that lead to reduction in the residual stresses.

Evaluation on Residual Stresses in Thick Titanium Welded Alloys

2018 ◽  
Vol 941 ◽  
pp. 1095-1098
Author(s):  
Hai Yan Zhao ◽  
Pu Xie
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Experimental Measurement ◽  
Contour Method ◽  
Weld Shape ◽  
Heating Stage

In this work, both Finite element simulated method and contour method experimental measurement are used to obtain residual stresses of different Titanium welded alloys, the results show that the maximum of the residual stress is mainly related to the internal restraint degree which formed inside of the thickness, the distribution of the residual stress depends primarily on the shape of weld shape. The heating stage plays a major role in relaxing the residual stress in this research. 95% of the residual stress is relieved in the temperature rising period, and about 75% of it is relieved in the temperature rising period when the temperature is above 500°C.

The Effect of Laser Cladding Deposition Rate on Residual Stress Formation in Ti-6Al-4V Clad Layers

2012 ◽  
Vol 520 ◽  
pp. 309-313 ◽  
Author(s):  
Ryan Cottam ◽  
K. Thorogood ◽  
Q. Lui ◽  
Yat Choy Wong ◽  
Milan Brandt
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Residual Stresses ◽  
Deposition Rate ◽  
Laser Cladding ◽  
Small Variation ◽  
Contour Method ◽  
Deposition Rates ◽  
Melt Pool ◽  
Stress Formation

The effect of deposition rate on the residual stresses formed during the laser cladding of Ti-6Al-4V powder onto a Ti-6Al-4V substrate was investigated. To isolate the deposition rate from the heat input an analytical laser cladding model was employed to control the melt pool depth to 0.1mm. The clad height was also held constant by the model at 1mm. The laser traversing speed was varied between 300 and 1500 mm/min. The residual stresses were measured using the contour method and it was found that the distribution of residual stress was similar for the different deposition rates and that there was a small variation in the tensile stress level reached in the clad and heat affected zone (HAZ) layer. The microstructures for all three clad layers were a’ martensite and the size of the HAZ was consistent from sample to sample. It was concluded that residual stress development is independent of deposition speed for the laser cladding of Ti-6Al-4V.

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.

scholarly journals Experimental Characterisation and Numerical Modelling of Residual Stresses in a Nuclear Safe-End Dissimilar Metal Weld Joint

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1298
Author(s):  
Shuyan Zhang ◽  
Zhuozhi Fan ◽  
Jun Li ◽  
Shuwen Wen ◽  
Sanjooram Paddea ◽  
...  
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Weld Joint ◽  
Steel Tube ◽  
Contour Method ◽  
Fe Modelling ◽  
Dissimilar Metal ◽  
Dissimilar Metal Weld ◽  
Metal Weld

In this study, a mock-up of a nuclear safe-end dissimilar metal weld (DMW) joint (SA508-3/316L) was manufactured. The manufacturing process involved cladding and buttering of the ferritic steel tube (SA508-3). It was then subjected to a stress relief heat treatment before being girth welded together with the stainless steel tube (316L). The finished mock-up was subsequently machined to its final dimension. The weld residual stresses were thoroughly characterised using neutron diffraction and the contour method. A detailed finite element (FE) modelling exercise was also carried out for the prediction of the weld residual stresses resulting from the manufacturing processes of the DMW joint. Both the experimental and numerical results showed high levels of tensile residual stresses predominantly in the hoop direction of the weld joint in its final machined condition, tending towards the OD surface. The maximum hoop residual stress determined by the contour method was 500 MPa, which compared very well with the FE prediction of 467.7 Mpa. Along the neutron scan line at the OD subsurface across the weld joint, both the contour method and the FE modelling gave maximum hoop residual stress near the weld fusion line on the 316L side at 388.2 and 453.2 Mpa respectively, whereas the neutron diffraction measured a similar value of 480.6 Mpa in the buttering zone near the SA508-3 side. The results of this research thus demonstrated the reasonable consistency of the three techniques employed in revealing the level and distribution of the residual stresses in the DMW joint for nuclear applications.

scholarly journals Residual Stresses in Ultrasonically Peened Fillet Welded Joints

2014 ◽  
Vol 996 ◽  
pp. 755-760 ◽  
Author(s):  
Bilal Ahmad ◽  
Michael E. Fitzpatrick
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Compressive Residual Stress ◽  
Fatigue Cracks ◽  
Steel Plates ◽  
Contour Method ◽  
Mechanical Method ◽  
Accelerated Corrosion ◽  
Accelerated Corrosion Testing ◽  
Measured Residual Stress

Fatigue cracks mostly initiate at areas subjected to high tensile residual stress and stress concentration. Ultrasonic peening is a mechanical method to increase fatigue life by imparting compressive residual stress. In this study residual stresses are characterized in fillet welded ship structural steel plates with longitudinal attachments. As-welded, ultrasonically peened, and specimens peened then subjected to accelerated corrosion testing were measured. Residual stress characterization was performed by the contour method and neutron diffraction.

FEM Simulation of the Effects of Residual Stress on Deformation of Gyroscope Frame

2010 ◽  
Vol 439-440 ◽  
pp. 838-841
Author(s):  
Jun Zhan ◽  
Gui Min Chen ◽  
Xiao Fang Liu ◽  
Qing Jie Liu ◽  
Qian Zhang
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Large Deformation ◽  
Deformation Process ◽  
Fem Simulation ◽  
Machining Process ◽  
The Core

Gyroscope is the core of an inertia system and made by machining process. Machining process imports large residual stress. The residual stress will be released and induces large deformation of gyroscope frame. In this paper, the effects of residual stress on deformation of gyroscope frame were simulated by finite element method. Different stress distribution leads different deformation. Compressive stress can make sample long and tensile stress make sample short. The stress released in deformation process which reduced about 90%.

Numerical Simulation of Residual Stresses due to Multipass Welding in High Strength Steel Plates and Validation against Experimental Measurements

2018 ◽  
Vol 941 ◽  
pp. 269-273
Author(s):  
Constant Ramard ◽  
Denis Carron ◽  
Philippe Pilvin ◽  
Florent Bridier
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
High Strength Steel ◽  
High Strength ◽  
Steel Plates ◽  
Contour Method ◽  
Hole Drilling ◽  
Experimental Measurements ◽  
Element Analysis ◽  
Multipass Welding

Multipass arc welding is commonly used for thick plates assemblies in shipbuilding. Sever thermal cycles induced by the process generate inhomogeneous plastic deformation and residual stresses. Metallurgical transformations contribute at each pass to the residual stress evolution. Since residual stresses can be detrimental to the performance of the welded product, their estimation is essential and numerical modelling is useful to predict them. Finite element analysis of multipass welding of a high strength steel is achieved with a special emphasis on mechanical and metallurgical effects on residual stress. A welding mock-up was specially designed for experimental measurements of in-depth residual stresses using contour method and deep hole drilling and to provide a simplified case for simulation. The computed results are discussed through a comparison with experimental measurements.

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