It is mentioned by Jones (in the paper "The credibility of predictions for structural designs subjected to large dynamic loadings causing inelastic behaviour") the coefficients in Cowper-Symonds equation vary significantly with strain and thickness.
For example: for 3mm thickness: C (1/s) is 24, q is 6.1 and C (1/s) is 116000, q is 5.3 for yield stress and ultimate stress, respectively.
Obviously, there is effect of those values on structural behaviour under dynamic loads.
So, could someone suggest me how to define the different Cowper-Symonds material constants for impact simulation in Abaqus?
Many thanks!
You can define different plasticity model for different strain rates simply by selecting the "use strain-rate-dependent data" option in "Edit Material" box of "Property" module.
Thank you so much for your answer.
Actually, I have just done with your suggestion, but I would like to apply the different coefficients in Cowper-Symonds equation for yield stress and ultimate stress because these coeff. would be changed along strain (Jones 2013).
Could you suggest me about this ?
Thank you very much.
Dac Dung Truong
Abaqus has not these material models like Cowper-Symonds ready for use. You need to tabulate your stress-strain data in Excel based on different constants of Cowper-Symonds model at first, and then define for Abaqus. I hope this can help you.
Hello,
Cowper and Symonds is simply the power law of rate dependent.
Best regards.
Sami
Dear Hai Tran,
Actually, we are using the Eq. provided by Lee & Lim (title paper is "A study on application of material properties in ship collision analysis", 2007) to calculate parameter C, while parameter q was assumed to be 5.
Best regards,
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