The Effect of Static and Dynamic Loading on Degradation of PLLA Stent Fibers

2013 ◽  
Author(s):  
Danika Hayman ◽  
Christie Bergerson ◽  
Samantha Miller ◽  
Michael Moreno ◽  
James E. Moore
Keyword(s):  
Dynamic Loading ◽  
Biodegradable Polymer ◽  
Degradation Rate ◽  
Polymer Degradation ◽  
Tensile Loading ◽  
The Body ◽  
Loading Conditions ◽  
Plla Stent ◽  
Static And Dynamic Loading ◽  
Degree Of Degradation

PLLA is a commonly used biodegradable polymer in stent designs because it is non-toxic and easily eliminated from the body. However, very little is known about the effect of loading conditions on the degradation rate. Rajagopal and Wineman developed a model of polymer degradation which is driven by load applied to the fiber [1]. Soares et. al. further developed this model for use with PLLA stent fibers under tensile loading conditions [2]. In this model the degradation rate is linearly related to deformation through the radius in the (IB, IIB) plane. Both models predict that greater deformation will induce a higher degree of degradation.

Testing of a tri-instrumented-treadmill unit for kinetic analysis of locomotion tasks in static and dynamic loading conditions

2007 ◽  
Vol 29 (3) ◽  
pp. 404-411 ◽  
Author(s):  
Gabriele Paolini ◽  
Ugo Della Croce ◽  
Patrick O. Riley ◽  
Frederic K. Newton ◽  
D. Casey Kerrigan
Keyword(s):  
Kinetic Analysis ◽  
Dynamic Loading ◽  
Loading Conditions ◽  
Dynamic Loading Conditions ◽  
Static And Dynamic Loading

Changing the Hardness Automotive Steels at Different Strain Rate

2014 ◽  
Vol 635 ◽  
pp. 41-44
Author(s):  
Miroslav Német ◽  
Mária Mihaliková ◽  
Alexandra Kovalčíkova ◽  
Anna Lišková
Keyword(s):  
Strain Rate ◽  
Dynamic Loading ◽  
Automotive Industry ◽  
Interstitial Free ◽  
Loading Conditions ◽  
Product Testing ◽  
Dynamic Conditions ◽  
Interstitial Free Steel ◽  
Dynamic Loading Conditions ◽  
Static And Dynamic Loading

Currently, the automotive industry used sheets of different qualities. The most common include IF (inter Interstitial Free) steel and alloyed steel. Use the sheet quality depends on the point of application in the production car. Testing and product testing is a standard part of the process of innovation and production itself. Testing of automotive steels under dynamic conditions is increasingly important. Changing the hardness HV 1 was performed on the fractured bars on the static and dynamic loading conditions. Tests were made on steel IF and S 460.

Evaluation of Friction at High Strain Rate using the Split Hopkinson Bar

2015 ◽  
Vol 651-653 ◽  
pp. 108-113 ◽  
Author(s):  
Archimede Forcellese ◽  
Edoardo Mancini ◽  
Marco Sasso ◽  
Michela Simoncini
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Dynamic Loading ◽  
High Strain ◽  
Outer Diameter ◽  
Loading Conditions ◽  
Split Hopkinson ◽  
Dynamic Loading Conditions ◽  
Static And Dynamic Loading ◽  
Frictional Behaviour

The present work aims at studying the influence of strain rate on the frictional behaviour of AA7075 aluminium alloy in the O-annealed temper state. To this purpose, ring compression tests were performed both under quasi-static and dynamic loading conditions. The high strain rate tests were carried out by means of the Split Hopkinson Tension-Compression Bar in the direct version. In both cases, hollow cylindrical samples, characterised by an initial outer diameter to inner diameter to height ratio of 6:3:2, were tested under dry condition and by lubricating with molybdenum disulphide grease. The different frictional behaviour exhibited by AA7075-O under quasi-static and dynamic loading conditions can be attributed to the strain rate effect both on the plastic flow behaviour of the deformed material, and on the thickness of the lubricant film.

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