Tear resistance
In simpler terms tear resistance (or tear strength) is a measure of how well a material can withstand the effects of tearing.[1] More specifically however it is how well a material (normally rubber) resists the growth of any cuts when under tension, it is usually measured in kN/m.[2] Tear resistance can be measured by the ASTM D 412 method (the same used to measure tensile strength, modulus and elongation). ASTM D 624 can be used to measure the resistance to the formation of a tear (tear initiation) and the resistance to the expansion of a tear (tear propagation). Regardless of which of these two is being measured, the sample is held between two holders and a uniform pulling force applied until the aforementioned deformation occurs. Tear resistance is then calculated by dividing the force applied by the thickness of the material.[2]
Materials with low tear resistance tend to have poor resistance to abrasion and when damaged will quickly fail (this includes hard materials, since hardness is not related to tear resistance).[2]
Tear resistance of different materials
Substances with high tear resistance include epichlorohydrin, natural rubber and polyurethane. At the opposite, materials such as silicone and fluorosilicone have low tear resistance.[2]
Tear-yield ratio
The ratio of tear resistance to the yield strength is called the tear-yield ratio. It is a measure of notch toughness.[3]
See also
References
- ↑ NAHAD GLOSSARY, http://www.nahad.org/aws/NAHAD/pt/sp/hsi_glossaries, 15 June 2012
- 1 2 3 4 Tear Resistance., http://www.rlhudson.com/O-Ring%20Book/selecting-physical6.html, 15 June 2012
- ↑ John Gilbert Kaufman (2001). intitle%3Aresistance&f=false Fracture Resistance of Aluminum Alloys: Notch Toughness, Tear Resistance Check
|url=value (help). ASM International. p. 38. ISBN 9780871707321.