robobobo
2007-05-22, 14:26
Hello everybody,
i have a problem. I make uniaxial tests (compression) with cylindrical elastomers without friction (I use Teflon). The strain is 8% and the frequency is 40Hz for example. I make 10000 load-cycles. Another test is with a strain of 4% and 10Hz. From the tests I get the loss modulus and the storage modulus for every strain and every frequency. I also get a hysteresis when I plot stress vs strain from the test data. Now I want to use abaqus to get a similar hysteresis like I get from the test data. I want to use a hyperelastic model (neo hook) with viscoelastic. My step I defined as sinusoidal boundery condition (displacement with amplitude-I hope it is right). Now I want to define the viscoelastic behaviour. I want to use the “domain: frequency” with “frequency: tabular” and “preload: uniaxial”. I put the frequency the strain and the loss modulus and storage modulus which I get from the tests and which are depending on the strain and the frequency. when I start the analysis I don´t get a hysteresis. Only a linear response. But when I use time domain with prony I get a hysteresis. But I want to use the frequency domain. Can someone tell me where my mistake is? Or does such analysis only work with time domain with prony?
Thank you.
I hope you can help me.
And sorry for my bad English!
i have a problem. I make uniaxial tests (compression) with cylindrical elastomers without friction (I use Teflon). The strain is 8% and the frequency is 40Hz for example. I make 10000 load-cycles. Another test is with a strain of 4% and 10Hz. From the tests I get the loss modulus and the storage modulus for every strain and every frequency. I also get a hysteresis when I plot stress vs strain from the test data. Now I want to use abaqus to get a similar hysteresis like I get from the test data. I want to use a hyperelastic model (neo hook) with viscoelastic. My step I defined as sinusoidal boundery condition (displacement with amplitude-I hope it is right). Now I want to define the viscoelastic behaviour. I want to use the “domain: frequency” with “frequency: tabular” and “preload: uniaxial”. I put the frequency the strain and the loss modulus and storage modulus which I get from the tests and which are depending on the strain and the frequency. when I start the analysis I don´t get a hysteresis. Only a linear response. But when I use time domain with prony I get a hysteresis. But I want to use the frequency domain. Can someone tell me where my mistake is? Or does such analysis only work with time domain with prony?
Thank you.
I hope you can help me.
And sorry for my bad English!