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Integrate on the cross section to find Moment and Torque
Posted 2014年1月6日 GMT-5 04:59 Parameters, Variables, & Functions, Structural Mechanics Version 4.3, Version 4.3a, Version 4.3b 1 Reply
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Does Comsol have specialised built in functions to find Moment and
Torque by integrating over the cross section of a surface modeled by 3-D elements?
Say I model 3-D CAntilever beam in Comsol using 3-D element. What do I need to do to calculate moment and TOrque?
The problem is that integration is done over the deformed surface and how do we define the distance of tractions from the neutral line?
How do we define neutral line in the beam made of 3D elements?
Torque by integrating over the cross section of a surface modeled by 3-D elements?
Say I model 3-D CAntilever beam in Comsol using 3-D element. What do I need to do to calculate moment and TOrque?
The problem is that integration is done over the deformed surface and how do we define the distance of tractions from the neutral line?
How do we define neutral line in the beam made of 3D elements?
1 Reply Last Post 2014年1月15日 GMT-5 04:18
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Posted:
1 decade ago
Hi,
I assume that you are interested in a general section (not the constrained one where the reaction force variables are available). You can the choose to integrate stresses over either the deformed configuration (Spatial frame) or the undeformed configuration (Material frame). The difference is important only if you are using geometric nonlinearity. But in that case you have to be sure to use the correct corresponding stresses. (See e.g. www.comsol.se/blogs/why-all-these-stresses-and-strains )
If you want to integrate more accurate variables than the stresses, you can switch on "Compute boundary fluxes" in the settings for the Solid Mechanics interface (available if Show Discretization has been selected). Do not use "Apply smoothing to boundary fluxes". In the result lists, the new variables will be found under Solid Mechanics->Stress->Internal nominal traction...
The neutral line can by found by an expression like
Regards,
Henrik
I assume that you are interested in a general section (not the constrained one where the reaction force variables are available). You can the choose to integrate stresses over either the deformed configuration (Spatial frame) or the undeformed configuration (Material frame). The difference is important only if you are using geometric nonlinearity. But in that case you have to be sure to use the correct corresponding stresses. (See e.g. www.comsol.se/blogs/why-all-these-stresses-and-strains )
If you want to integrate more accurate variables than the stresses, you can switch on "Compute boundary fluxes" in the settings for the Solid Mechanics interface (available if Show Discretization has been selected). Do not use "Apply smoothing to boundary fluxes". In the result lists, the new variables will be found under Solid Mechanics->Stress->Internal nominal traction...
The neutral line can by found by an expression like
Regards,
Henrik