The Damage Zone in Some Ductile Polymers under a Triaxial Tensile Stress State

Author(s):  
A. Tse ◽  
E. Shin ◽  
A. Hiltner ◽  
E. Baer
1991 ◽  
Vol 26 (19) ◽  
pp. 5374-5382 ◽  
Author(s):  
A. Tse ◽  
E. Shin ◽  
A. Hiltner ◽  
E. Baer

2021 ◽  
Vol 883 ◽  
pp. 303-308
Author(s):  
Peter Hetz ◽  
Matthias Lenzen ◽  
Martin Kraus ◽  
Marion Merklein

Numerical process design leads to cost and time savings in sheet metal forming processes. Therefore, a modeling of the material behavior is required to map the flow properties of sheet metal. For the identification of current yield criteria, the yield strength and the hardening behavior as well as the Lankford coefficients are taken into account. By considering the anisotropy as a function of rolling direction and stress state, the prediction quality of anisotropic materials is improved by a more accurate modeling of the yield locus curve. According to the current state of the art, the layer compression test is used to determine the corresponding Lankford coefficient for the biaxial tensile stress state. However, the test setup and the test procedure is quite challenging compared to other tests for the material characterization. Due to this, the test is only of limited suitability if only the Lankford coefficient has to be determined. In this contribution, a simplified test is presented. It is a reduction of the layer compression test to one single sheet layer. So the Lankford coefficient for the biaxial tensile stress state can be analyzed with a significantly lower test effort. The results prove the applicability of the proposed test for an easy and time efficient characterization of the biaxial Lankford coefficient.


2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878952 ◽  
Author(s):  
Weiwei Liu ◽  
Kai Cheng ◽  
Jun Wang

Rubber-tracked transporters are becoming increasingly popular in agriculture, forestry and military transportation. Rubber track systems are typically fitted instead of using tyres on the transporter to decrease soil stress and increase trafficability. Therefore, the accurate failure analysis of a rubber track is important. A model for predicting stress distribution along a rubber track is presented in this study. In the model, the stress along a rubber track consists of the vertical stress below the rubber track, tensile stress, bending stress and centrifugal tensile stress. Moreover, fourth strength theory was used to change a complicated stress state to a simple stress state. An experiment was performed at the test site of Harbin First Machinery Building Group Ltd, with a total weight of 61.789 kN. The experiment was conducted to verify and approve the theoretical model. The Miner rule was used to predict the cycle index and working hour of the rubber track, thereby providing a method for predicting the fatigue life of a rubber track.


2010 ◽  
Vol 97-101 ◽  
pp. 500-503 ◽  
Author(s):  
Jian Wei Li ◽  
Min Qiang Xu ◽  
Jian Cheng Leng ◽  
Ming Xiu Xu

Magnetic behavior of ferromagnetic materials has been using to detect defects of materials. To evaluate the stress states of the components by the magnetic memory signal, Q235 defect asymmetrical samples were made. The characteristics of magnetic memory of Q235 have been studied in the three different testing environments which are online-loading, online-unloading and offline-unloading under cycle tensile stress. The results show that magnetic memory signals have different characteristics in different testing environment. It is feasible to evaluate preliminarily the stress state by the magnetic memory signals.


2013 ◽  
Vol 438-439 ◽  
pp. 1546-1550
Author(s):  
Jin Chao Yue ◽  
Xiao Bin Zhang ◽  
Ling Min Ye

The vibrant-type-disintegration method is applied to calculate structure seismic action of a weir dam. Based on calculation and analysis of the weir dam, special attention is paid to the stress state of key parts. The results show that the displacement and stress of weir dam are affected by earthquake excitation direction. Since large principal tensile stress appears in the joint of girder and pier, and the zone of principal tensile stress is large because of the thrust of radial gate and steep changes of geometry shape, we should pay special attention when calculating anti-seismic checking and reinforcement arrangement.


2009 ◽  
Vol 89 (1) ◽  
pp. 87-90 ◽  
Author(s):  
G. Isgró ◽  
O. Addison ◽  
G.J.P. Fleming

Stress-induced changes imparted in a ‘dentin-bonded-crown’ material during sintering, annealing, pre-cementation surface modification, and resin coating have been visualized by profilometry. The hypothesis tested was that operative techniques modify the stressing pattern throughout the material thickness. We polished the upper surfaces of 10 ceramic discs to remove surface imperfections before using a contact profilometer (40-nm resolution) to measure the ‘flatness’. Discs were re-profiled after annealing and after alumina particle air-abrasion and resin-coating of the ‘fit’ surface. Polished surfaces were convex, with a mean deflection of 8.4 ± 1.5 μm. Mean deflection was significantly reduced (P = 0.029) following alumina particle air-abrasion and increased (P < 0.001) on resin-coating. Polishing induced a tensile stress state, resulting in surface convexity. Alumina particle air-abrasion reduced the relative tensile stress state of the contralateral polished surface. Resin-polymerization generated compression within the resin-ceramic ‘hybrid layer’ and tension in the polished surface and is likely to contribute to the strengthening of ceramics by resin-based cements.


2007 ◽  
Vol 348-349 ◽  
pp. 965-968
Author(s):  
Akihide Saimoto ◽  
Akira Toyota ◽  
Yasufumi Imai

Compression induced formation of a damage zone, which would result in a shear fault in brittle solids is studied. In a compression test of flawed PMMA, an apparent damage zone composed of large number of scattered cracks, which have no intersection but exist closely with each other, is experienced. The damage zone first appears in a vicinity of tips of artificial flaw and then extends gradually with increase of applied compression. The direction of extension of damage zone is observed to incline about 0 30 from the axis of principal compression. A mechanism of the extension of damage zone with increase of applied compression is discussed using a scattered cracking model. It was found that each crack composing the damage zone has a possibility to open due to crack-to-crack interaction and a localized tensile stress appears both inside and outside of the damage zone. The localized tension appeared in the interior of the damage zone may increase crack density, while that of appeared in the exterior of the damage zone could bring an extension of the damage zone.


2014 ◽  
Vol 624 ◽  
pp. 630-634 ◽  
Author(s):  
Qi Fan ◽  
Shuan Cheng Gu ◽  
Bo Nan Wang ◽  
Rong Bin Huang

Geotechnical engineering in tension damage is one of the major failure modes. For a long time, Brazil test has practical significance and wide application value that has been used to determine the tensile strength of rock. When the specimen center destroyed tensile stress play a major role that is the theoretical basis of Brazil test. This is uniaxial tensile stress state, but the reality is complex stress state. Theoretical analysis shows that the Brazilian test does not truly reflect the tensile strength of rock, its test results to error. In this paper, two-parameter parabolic Mohr strength criterion for this error analysis, and propose amendments to the formula.


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