hysteresis in shear test

[nut]

Hello Dr. Bergstrom

I tried to predict the hysteresis loop in cyclic shear cylindrycal elastomer block and change in different fequency. The results show that at low frequency have more hysteresis loop area than high frequency. What's happen? Because the result was fine in tension and compression model.

Thank a lot

[Jorgen]

Did you get good predictions at different frequencies in tension and compression, but not in shear? What model did you use for the predictions? What material are you studying?

- Jorgen

[nut]

Hi again

I used SBR0 as my materials. I calculated the material parameter from unixial compression test. The prediction of unixial compression is well but at the high strain rate,the results deviate from the experiment data. Also at I applied the materials paramter to unixial tension model. The resuls is completely different . I think because the we calculated the intitial shear modulus by pick up one point at the compression curve which cannot use to predict in tensile model. Also, in dynamic shear test at very high frequency the hysteresis loop is smaller than at a slow frequency. I'm not sure what's happen?

Thank you very much

[Jorgen]

I don't know what material model that you are using, but it sounds like you are using an inappropriate material model.

I have successfully used the Bergstrom-Boyce (BB) model (http://www.polymerfem.com/modules.php?name=Downloads&d_op=getit&lid=7) to predict the dynamic behavior of many different types of elastomers.

- Jorgen