scholarly journals Passive arching in rubberized sand backfills

2020 ◽  
Vol 57 (4) ◽  
pp. 549-567
Author(s):  
Hamidreza Khatami ◽  
An Deng ◽  
Mark Jaksa
Keyword(s):  
Deformation Process ◽  
High Speed ◽  
Pressure Sensors ◽  
Coarse Sand ◽  
Image Correlation ◽  
Correlation Technique ◽  
High Speed Imaging ◽  
Digital Image Correlation Technique ◽  
Stress Profiles ◽  
Stress Variations

The deformation and stress profiles of passive arching in a coarse sand and two rubberized sand backfills were investigated using a trapdoor apparatus. The trapdoor apparatus was instrumented with high-speed imaging equipment and a series of pressure sensors. The images of the deformation process in the backfills were analysed using the digital image correlation technique. The effect of a local surcharge on the deformation and stress profiles was also examined. It was observed that the rubber inclusions helped reduce the deformation of the backfills. Passive arching moduli and stress variations between the backfills examined are compared.

Stent Expansion in Curved Vessel and Their Interactions: An In Vitro Study

2014 ◽  
Author(s):  
Shijia Zhao ◽  
Shengmao Lin ◽  
Linxia Gu
Keyword(s):  
High Speed ◽  
In Vitro Study ◽  
Image Correlation ◽  
Correlation Technique ◽  
Digital Image Correlation Technique ◽  
Stent Expansion ◽  
Curved Artery ◽  
Induced Changes ◽  
Stenting Procedure

The objective of this work is to characterize the interaction between balloon-expandable stents and curved artery simulants. The deformation at the outer surface of the curved artery simulant was monitored using two high-speed cameras, and the corresponding strain map was obtained with 3-D digital image correlation technique. The anisotropic variations in the arterial mechanics were clearly observed. Results indicated three distinct phases during the stenting procedure, i.e., expansion, recoil and stabilization. The stent expansion dramatically altered the strain field of the curved artery simulant, and larger strain was observed around the center of stent than its two ends. In addition, the change in curvature of the simulant during the implantation of stent was quantified. This work characterized and quantified the interaction between stent and artery simulant in a laboratory setting, which could facilitate the optimization of the stent design for minimizing the stent-induced changes in the mechanical environment of artery.

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

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