mikechy
Mechanical
- Sep 18, 2008
- 37
Hi All,
I'd like to plot stress-strain (stretch) curves to compare different rubber materials (I have Mooney or Ogden constant already).
For Mooney-Rivlin material, I can calculate stress S as
S=(2C1+2C2/d)(d-1/d^2)
where C1 and C2 are Constants and d is the stretch ratio, defined as the ratio of the stretched length to the initial length of the sample. This can be defined in terms of the measured strain in a simple tensile test
d=e+1. .
For Ogden material there is other formula:
S=Sum(mn(d^(bn-1)-d^(-1(1+0.5bn)))
where m and b are Constants, and index n - order of Ogden model (it's all about a simple tension).
For Mooney and Ogden n=2 it works: I try it with different C1 and C2 , and m and b data from literature and it's OK. But for n=3 it doesn't work. Does anyone know how to do it for such case? Thanks
Regards,
Mike
I'd like to plot stress-strain (stretch) curves to compare different rubber materials (I have Mooney or Ogden constant already).
For Mooney-Rivlin material, I can calculate stress S as
S=(2C1+2C2/d)(d-1/d^2)
where C1 and C2 are Constants and d is the stretch ratio, defined as the ratio of the stretched length to the initial length of the sample. This can be defined in terms of the measured strain in a simple tensile test
d=e+1. .
For Ogden material there is other formula:
S=Sum(mn(d^(bn-1)-d^(-1(1+0.5bn)))
where m and b are Constants, and index n - order of Ogden model (it's all about a simple tension).
For Mooney and Ogden n=2 it works: I try it with different C1 and C2 , and m and b data from literature and it's OK. But for n=3 it doesn't work. Does anyone know how to do it for such case? Thanks
Regards,
Mike