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Specifying maximum tensile strain in Comsol
Posted 4 giu 2013, 22:09 GMT-4 Materials, Structural Mechanics Version 4.3a 2 Replies
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Hi everyone,
My question is on material properties available in Comsol.
I'm using the solid mechanics module of Comsol, and the analysis type is stationary. Currently I have included an elasto-plastic material in my modelling. But I need to include a maximum value for the tensile strain developed within the material. My question is, is there any way to specify a maximum tensile strain (or the tensile strength) of the material in Comsol? Can I perform this by altering the same elasto-plastic material model which I'm currently working on?
Many Thanks in advance!
My question is on material properties available in Comsol.
I'm using the solid mechanics module of Comsol, and the analysis type is stationary. Currently I have included an elasto-plastic material in my modelling. But I need to include a maximum value for the tensile strain developed within the material. My question is, is there any way to specify a maximum tensile strain (or the tensile strength) of the material in Comsol? Can I perform this by altering the same elasto-plastic material model which I'm currently working on?
Many Thanks in advance!
2 Replies Last Post 13 giu 2013, 00:32 GMT-4
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Posted:
1 decade ago
Hi,
This is generally difficult for numerical reasons. What do you expect to happen when that limit is exceeded? If the material breaks, then there will be no stiffness, and generally the model will become singular, at least as long as the analysis is stationary or quasistatic.
You can experiment with making your hardening function decrease after a certain strain has been exceeded, but the chances that you will get a converged solution are small.
A comment to the physics: The ultimate tensile strain is not a pure physical quantity, but rather a property of the test specimen geometry. It is thus difficult to draw any conclusions about when the material will break in a general stress state based on the ultimate tensile strain from a pure tensile test.
Regards,
Henrik
This is generally difficult for numerical reasons. What do you expect to happen when that limit is exceeded? If the material breaks, then there will be no stiffness, and generally the model will become singular, at least as long as the analysis is stationary or quasistatic.
You can experiment with making your hardening function decrease after a certain strain has been exceeded, but the chances that you will get a converged solution are small.
A comment to the physics: The ultimate tensile strain is not a pure physical quantity, but rather a property of the test specimen geometry. It is thus difficult to draw any conclusions about when the material will break in a general stress state based on the ultimate tensile strain from a pure tensile test.
Regards,
Henrik
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Posted:
1 decade ago
Hi Henrik,
Many Thanks for your reply!
What I’m modelling is a composite material comprising of several different phases. I assume that the composite material reaches its maximum capacity whenever the maximum strains of any individual phase reaches its own strain capacity. So, I need to specify the maximum strain each individual phase can withstand….
I’ll try with decreasing the hardening function as suggested as well.
Best Regards,
Madhu.
Many Thanks for your reply!
What I’m modelling is a composite material comprising of several different phases. I assume that the composite material reaches its maximum capacity whenever the maximum strains of any individual phase reaches its own strain capacity. So, I need to specify the maximum strain each individual phase can withstand….
I’ll try with decreasing the hardening function as suggested as well.
Best Regards,
Madhu.