Estimation of Texture-dependent Stress-Strain Curve and r-value of Aluminum Alloy Sheet Using Deep Learning

2020 ◽  
Vol 61 (709) ◽  
pp. 48-55
Author(s):  
Kohta KOENUMA ◽  
Akinori YAMANAKA ◽  
Ikumu WATANABE ◽  
Toshihiko KUWABARA
2020 ◽  
Vol 61 (12) ◽  
pp. 2276-2283 ◽  
Author(s):  
Kohta Koenuma ◽  
Akinori Yamanaka ◽  
Ikumu Watanabe ◽  
Toshihiko Kuwabara

2015 ◽  
Vol 30 (14) ◽  
pp. 2222-2230 ◽  
Author(s):  
Halim Al Baida ◽  
Cécile Langlade ◽  
Guillaume Kermouche ◽  
Ricardo Rafael Ambriz

Abstract


2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Y. W. Kwon ◽  
Y. Esmaeili ◽  
C. M. Park

Because most structures are subjected to transient strain-rate loading, an experimental study was conducted to investigate the stress-strain behaviors of an aluminum alloy undergoing varying strain-rate loading. To this end, uniaxial tensile loading was applied to coupons of dog-bone shape such that each coupon underwent two or three different strain-rates, i.e., one rate after another. As a basis, a series of single-strain-rate tests was also conducted with strain-rates of 0.1–10.0 s−1. When the material experienced multistrain-rate loading, the stress-strain curves were significantly different from any single-strain-rate stress-strain curve. The strain-rate history affected the stress-strain curves under multistrain-rate loading. As a result, some simple averaging of single-strain-rate curves did not predict the actual multistrain-rate stress-strain curve properly. Furthermore, the fracture strain under multistrain-rate loading was significantly different from that under any single-strain-rate case. Depending on the applied strain-rates and their sequences, the former was much greater or less than the latter. A technique was proposed based on the residual plastic strain and plastic energy density in order to predict the fracture strain under multistrain-rate loading. The predicted fracture strains generally agreed well with the experimental data. Another observation that was made was that the unloading stress-strain curve was not affected by the previous strain-rate history.


Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1129 ◽  
Author(s):  
Lirong Sun ◽  
Zhongyi Cai ◽  
Dongye He ◽  
Li Li

A new method, by directly utilizing original measured data (OMD) of the stress–strain relation in the Marciniak–Kuczynski (M–K) model, was proposed to predict the forming limit curve (FLC) of an aluminum alloy sheet. In the groove zone of the M–K model, by establishing the relations of the equivalent strain increment, the ratio of shear stress to the first principle stress and the ratio of the second principle stress to the first principle stress, the iterative formula was established and solved. The equations of theoretical forming limits were derived in detail by using the OMD of the stress–strain relation. The stretching specimens of aluminum alloy 6016-T4 were tested and the true stress–strain curve of the material was obtained. Based on the numerical simulations of punch-stretch tests, the optimized specimens’ shape and test scheme were determined, and the tests for FLC were carried out. The FLC predicted by the proposed method was more consistent with the experimental results of FLC by comparing the theoretical FLCs based on OMD of the stress–strain relation and of that based on traditional power function. In addition, the influences of anisotropic parameter and groove angle on FLCs were analyzed. Finally, the FLC calculated by the proposed method was applied to analyze sheet formability in the stretch-forming process, and the predicted results of FLC were verified by numerical simulations and experiments. The fracture tendency of the formed parts can be visualized in the forming limit diagram (FLD), which has certain guiding significance for fracture judgment in the sheet-forming process.


2014 ◽  
Vol 611-612 ◽  
pp. 27-32 ◽  
Author(s):  
Takayuki Hama ◽  
Tsuyoshi Mayama ◽  
Hirohiko Takuda

In the present study, the deformation behavior of a cast Mg alloy sheet that had random crystallographic orientations was studied both experimentally and numerically. Although the crystallographic orientations were random, the stress-strain curve was asymmetric between tension and compression: the flow stress under tension was higher than that of compression. Moreover, the stress-strain curve exhibited a strain path dependency: a slightly sigmoidal curve occurred under tension following compression, while it did not occur under compression following tension. Clearly, such tendencies were similar to those observed in rolled Mg alloy sheets although the tendencies were less pronounced in the cast Mg alloy sheet. A crystal plasticity finite-element method was used to understand the mechanism of these results. Simulation results showed that the asymmetry and the strain path dependency in the stress-strain curves occurred in the cast Mg alloy sheet because of the asymmetry in the activity of twinning between tension and compression as in the case of rolled Mg alloy sheets.


2012 ◽  
Vol 450-451 ◽  
pp. 252-256
Author(s):  
Jin Ping Hu

This paper first studied aluminum alloy honeycomb sandwich panel in out- plane static compress test.Through analyzing deformation characteristics, the loads-displacement relationship was obtained and are described by the average stress-strain curve. Secondly, using the Split Hopkinson Pressure Bar device of impact test, deformation behaviour,dynamic average stress-strain curve data and so on were got under different loading rates, thus learned impact dynamics characteristics of that.


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