scholarly journals Residual Stress Analysis of a 2219 Aluminum Alloy Ring Using the Indentation Strain-Gauge Method

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 979
Author(s):  
Yunlong Ma ◽  
Nianpu Xue ◽  
Qiong Wu ◽  
Hanjun Gao ◽  
Jian Wu
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Strain Gauge ◽  
Expansion Method ◽  
Element Model ◽  
Maximum Principal Stress ◽  
Initial Residual Stress ◽  
2219 Aluminum Alloy ◽  
Rolling Ring ◽  
Indentation Strain

Aerospace thin-walled rings are vulnerable to machining distortion during the manufacturing process. Various research results show that the main factor causing machining deformation is initial residual stress inside the blank. In this study, the residual stress of a 2219 aluminum alloy ultra-large rolling ring was measured by using the indentation strain-gauge method. Results showed the maximum residual maximum principal stress was +265 MPa and stress distribution was uneven. To homogenize the initial residual stress of the ring, an expansion method is proposed based on the principle of pre-stretching plate, and the feasibility of the expansion method was analyzed by establishing a simplified theoretical model of ring. A FE (Finite Element) model was established to investigate residual-stress evolution during the rolling ring and the expanding ring process. The expansion simulation results show that the reduction rates of residual stress were greater than 40% and the maximum residual stress was only 65 MPa.

scholarly journals Micro-Hardness and Residual Stress Relaxation of 2024 T351 Aluminum Alloy

2011 ◽  
Vol 462-463 ◽  
pp. 343-348 ◽  
Author(s):  
Omar Suliman Zaroog ◽  
Aidy Ali ◽  
Sahari B. Barkawi ◽  
Rizal Zahari
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Stress Relaxation ◽  
Shot Peening ◽  
X Ray Diffraction ◽  
Initial State ◽  
Load Amplitude ◽  
Initial Residual Stress ◽  
Residual Stress Relaxation ◽  
Two Stages

The residual stress relaxation can be divided into two stages: The first cycle relaxation and the following cycles. In both stages, residual stress relaxed considerably from the initial state. The aim of this study is to investigate the residual stress relaxation and microhardness reduction after first and second cyclic load. A 2024 T351 aluminum alloy specimens were shot peened into three shot peening intensities. The fatigue test for first and second cyclic loads of two loads 15.5 kN and 30 kN was performed. The initial residual stress and residual stress after the first and second cycle stress was measured for the three shot peening intensities using X-ray diffraction. Microhardness test was performed for each specimen. The results showed that the residual stress relaxation for first cycle was reached more than 40% of the initial residual stress and it depends on the load amplitude, and microhardness decreased for the first cycle reached 22% and also it depended on load amplitude.

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%.

scholarly journals Residual Stress Relief for 2219 Aluminum Alloy Weldments: A Comparative Study on Three Stress Relief Methods

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 419 ◽  
Author(s):  
Shu-Guang Chen ◽  
Yi-Du Zhang ◽  
Qiong Wu ◽  
Han-Jun Gao ◽  
Dong-Yang Yan
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Longitudinal Direction ◽  
Stress Relief ◽  
The Other ◽  
Good Effect ◽  
Stress Release ◽  
Maximum Reduction ◽  
Vibration Stress ◽  
2219 Aluminum Alloy

Thermal stress relief (TSR), vibration stress relief (VSR), and thermal and vibratory Stress relief (TVSR) have all been proven to be effective for residual stress relief. So far, no comparison has been made between the effects on residual stress relief of these three stress release methods. In this study, twelve 2219 aluminum alloy welding samples were divided into four groups. One of the groups is used as a reference without any stress relief treatment. The other three groups were processed by TSR, VSR, and TVSR, respectively. The residual stresses of depths of 0–1.2 mm are measured. Results show that small and uniform stresses are observed in the 2219 aluminum alloy welding samples after TSR, VSR, and TVSR treatment. TSR treatment decreased the peak residual stress much more than VSR and TVSR treatment. The maximum reduction of the peak residual stress is 50.8% (210 °C) in the transversal direction and 42.02% (185 °C) in the longitudinal direction after TSR treatment with the temperature range 140 °C to 210 °C. In terms of residual stress homogenization, although the TSR treatment has an advantage perpendicular to the weld direction, the effect parallel to the weld direction is not ideal. The TVSR has a good effect in both directions.

Welding Distortion Minimization for an Aluminum Alloy Extruded Beam Structure Using a 2D Model

2004 ◽  
Vol 126 (1) ◽  
pp. 52-63 ◽  
Author(s):  
Bart O. Nnaji ◽  
Deepak Gupta ◽  
Kyoung-Yun Kim
Keyword(s):  
Aluminum Alloy ◽  
Quality Index ◽  
Bending Moment ◽  
Element Model ◽  
Maximum Principal Stress ◽  
Welding Distortion ◽  
Beam Structure ◽  
Critical Areas ◽  
Distortion Minimization ◽  
Nonlinear Transient

Optimization of the weld sequence of a sub-assembly composed of thin walled aluminum alloy extruded beams is investigated and presented. The main factor considered is the quality of the assembly after welding, which is measured by the deformation behavior at pre-defined critical locations. The aluminum alloy extruded beam structure is simplified by a 2-D beam element model. Our methodology consists of applying pre-estimated angular shrinkages for each welding step thus eliminating use of a complex nonlinear transient analysis which would require consideration of thermo-mechanical interactions and plasticity. Two distortion modes (angular shrinkage and tilting shrinkage) are investigated and applied to model welding distortion. Different criteria for minimization of welding distortion have been investigated, such as overall deformation or weighted deformation with emphasis on some critical areas. A composite quality index is formulated, which is a weighted measure of critical deformation and the overall deformation. For simulating welding deformation and the role of sequences, some weld sequences were selected heuristically and they were simulated in ANSYS 5.2. Based on the quality index of these sequences, some were reproduced while mutating other portions of these sequences to find better sequences. Finally, deformation data for each node and weighted measures of deformation for considered sequences are presented, and final deformed shapes for different sequences, maximum principal stress, and bending moment across the beams are shown graphically.

Evaluate welding residual of 6082-T6 aluminum alloy welded plate by using ultrasonic method

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940038
Author(s):  
Zhongyin Zhu ◽  
Guoqing Gou ◽  
Zhiyi Zhang ◽  
Chuanping Ma ◽  
Wei Gao
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Ultrasonic Method ◽  
Welding Process ◽  
Diffraction Method ◽  
Element Model ◽  
Hole Drilling ◽  
X Ray Diffraction ◽  
Effective Depth ◽  
Good Agreement

The residual stress beneath the surface is crucial to the safety of the structures. Neutron Diffraction and Hole-drilling are the two methods being used to measure the inner residual stress. Longitudinal Critically Refracted (LCR) wave transmission that is propagated parallel to surface also can be used for measuring residual stress, but measurements are within an effective depth and need to be further studied. In this paper, the parameters of K are separately tested in WZ, HAZ and BM zone. The welding process of 6082-T6 aluminum alloy welded joints is simulated in SYSWELD, the finite element model has been verified by the X-ray diffraction method. The residual stress value calculated by SYSWELD and the values obtained from the ultrasonic measurement show a good agreement. It is demonstrated that the residual stress of 6082-T6 aluminum alloy welded plate can be evaluated by using the ultrasonic method.

Numerical Simulation of the Cold Expansion and Residual Stress Relaxation for Aluminum Alloy 7050

2011 ◽  
Vol 117-119 ◽  
pp. 1656-1661
Author(s):  
Di Guan ◽  
Qin Sun
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Stress Relaxation ◽  
Room Temperature ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Residual Stress Field ◽  
Cold Expansion ◽  
Beneficial Effects ◽  
Residual Stress Relaxation

Cold expansion is a well-known technique for improving the fatigue life of fastener holes in aeronautical structures by introducing a compressive residual stress field around them. In this paper, a 3-D finite element model is used to analyze the residual stress distribution and relaxation around an expanded hole for aluminum alloy 7050. The results reveal that the cutting process of split sleeve cold expansion and creep are main reason for residual stress relaxation in room temperature, which may limit the beneficial effects of cold expansion.

Optimization of Bulkhead Processing Sequence for Multi-Frame Monolithic Components by FEM

2007 ◽  
Vol 24-25 ◽  
pp. 355-360 ◽  
Author(s):  
Zhi Tao Tang ◽  
Zhan Qiang Liu ◽  
Xing Ai
Keyword(s):  
Residual Stress ◽  
Material Properties ◽  
Element Model ◽  
Clamping Force ◽  
Processing Sequence ◽  
Initial Residual Stress ◽  
Machining Deformation ◽  
Proposed Model ◽  
Key Techniques ◽  
Monolithic Components

When machining aerospace monolithic components, most of materials could be removed, resulting in severe deformation of the parts due to the release and redistribution of the blank’s original residual stress, together with the action of cutting loads and clamping force. A finite element model (FEM) is built for predicting the deformation caused by those factors mentioned above. In this model, some key techniques such as material properties, initial residual stress model, and application of dynamic cutting loads and transformation of boundary condition are discussed in details. The proposed model predicts the machining deformation for multi-frame monolithic components. Particular attention is paid to the influence of the bulkhead processing sequence on part deformation. At last the paper puts forwards optimal bulkhead processing sequence based on minimizing the machining deformation.

scholarly journals Thermal Residual Stress Analysis of Soldering and Lamination Processes for Fabrication of Crystalline Silicon Photovoltaic Modules

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3256 ◽  
Author(s):  
Hyunseong Shin ◽  
Ekyu Han ◽  
Nochang Park ◽  
Donghwan Kim
Keyword(s):  
Residual Stress ◽  
Principal Stress ◽  
Crystalline Silicon ◽  
Element Model ◽  
Maximum Principal Stress ◽  
Mechanical Failure ◽  
Soldering Process ◽  
Pv Module ◽  
Wafer Thickness ◽  
Pv Modules

In this study, we developed a finite element model to assess the residual stress in the soldering and lamination processes during the fabrication of crystalline silicon (Si) photovoltaic (PV) modules. We found that Si wafers experience maximum thermo-mechanical stress during the soldering process. Then, the Si solar cells experience pressure during the process of lamination of each layer of the PV module. Thus, it is important to decrease the residual stress during soldering of thin Si wafers. The residual stress is affected by the number of busbars, Si wafer thickness, and solder type. Firstly, as the number of busbars increases from two to twelve, the maximum principal stress increases by almost a factor of three (~100 MPa). Such a high first principal stress can cause mechanical failure in some Si wafers. Secondly, thermal warpage increases immediately after the soldering process when the thickness of the Si wafers decreases. Therefore, the number and width of the busbars should be considered in order to avoid mechanical failure. Finally, the residual stress can be reduced by using low melting point solder. The results obtained in this study can be applied to avoid mechanical failure in PV modules employing thin Si wafers.

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