29 May 2002 Propagation and pulsation of slip band using dynamic digital speckle pattern interferometry
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Proceedings Volume 4537, Third International Conference on Experimental Mechanics; (2002); doi: 10.1117/12.468785
Event: Third International Conference on Experimental Mechanics, 2002, Beijing, China
Abstract
The phenomena of Portevin-Le Chatelier (PLC) band propagation and its pulsation accompanying the serration of load curve in a tensile test of aluminum alloy were directly observed by using dynamic digital speckle pattern interferometry method. In the plastic deformation stage, a slip band is formed and propagates repeatedly along the tensile direction with a certain speed and a certain bandwidth. The propagation speed decreases gradually with the increasing of plastic deformation, and finally the specimen cracks at the position where the band stops. The same slip fringe patterns observed from the front surface and rear surface of the specimen simultaneously show that the slip plane goes through the thickness of specimen. Pulsation of fringe density in the inside of the slip band accompanying with the serrations of load curve was observed. The pulsation period corresponds with the width of the serration. When the load falls in the serrations, the slip deformation happens just like an avalanche, and the time of the avalanche slip is less than 0.03 seconds. Corresponding to the happening of the avalanche slip, dense shrinkage fringes appear on the outside of the slip band. The specimen takes a shrinkage deformation in the outside of the slip band to compensate the elongation deformation in slip band at the moment of avalanche slip, even for a tensile test. The elongation value in the inside of the slip band causing by the avalanche slip is in the order of 10 micrometers by calculating with observed results.
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Qing-Chuan Zhang, Satoru Toyooka, Xiaoping Wu, "Propagation and pulsation of slip band using dynamic digital speckle pattern interferometry", Proc. SPIE 4537, Third International Conference on Experimental Mechanics, (29 May 2002); doi: 10.1117/12.468785; https://doi.org/10.1117/12.468785
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KEYWORDS
Fringe analysis

Speckle pattern

Aluminum

Interferometry

Photonic integrated circuits

Atmospheric propagation

Chemical species

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