Dear
I want ask related to relaxation test. As I know there are 3 type of relaxations test, they are simple tension test, pure shear test and equal biaxial test. I intend to obtain shear modulus and bulk modulus of rubber material. and I have tested the rubber on the axel product as "simple tension test stress relaxation".
My question; Could I use the result test (tension relaxation test) to obtain the shear modulus (G)?
or in order to obtain shear modulus (G) I must obtain the data from pure shear test (stress relaxation test)?
Please give me advice.
Best Regards
Yudha Lesmana
Yes, you may use only the results of tension relaxation test to obtain the shear modulus G if the Posson ratio is a known and preserve constant value under loading. Then we have the relation between shear and bulk modulus
All the best
As pointed out by Dr. Serge, you can always calculate bulk and shear modulus using the mutual relationship between them. However, this comes with an assumption that Poisson's ratio remain constant with. Most of the time this may not be the case. Poisson's ratio may change with time and temperature also (some reference are attached). In that case conservation will not be accurate.
http://silver.neep.wisc.edu/~lakes/VEPoisson.pdf
http://www.ing.unitn.it/~pegorett/resources/papers/94-Pandini-Time-temperaure-effects-on-Poisson-ratio-of-PBT.pdf
It was well answered by Dr. Serge and Anshul. I would like to add that if you want the bulk modulus experimentally, you can do a volumetric test to characterize the compressibility of rubber material.
- Badges
- Science topic
- Similar topics
- Biological Science
- Physiology
- Physiological Processes
- Stress