Tension-Compression non-linearity of Cartilage

[Shamimur Akanda]

Hello,

I have a question regarding the tension-compression nonlinearity behavior of cartilage. I modeled an isotropic cartilage and also an anisotropic cartilage showing depth-dependent fibers. Then I applied a simple creep test on both the models. I did not find any difference in the displacement of the center of the top surface. Is it supposed to like this or am I doing something wrong? Thank you.

Shamimur

[ateshian]

Hi Shamimur,

There is not enough information in your post to answer your question. Was the creep test performed in confined compression? In that case, tension-compression nonlinearity does not have an effect on the response in that configuration, since there is no tension. Was it in unconfined compression, indentation, or some other testing configuration? Are you comparing homogeneous and inhomogeneous models that both include tension-compression nonlinearity? In that case, it is not tension-compression that would influence the response, but inhomogeneity. Why would you expect that focusing only on the displacement at the center of the top surface should exhibit different behavior in both models? What about the stress-distribution, or the fluid pressure (if you are doing a biphasic anlaysis) throughout the domain of your analysis? Based on these questions I hope you understand that it is not possible to say if you are doing something wrong with the information you provided.

Best,

Gerard