Abaqus General Beam Element - Torsional Rigidity
Abaqus General Beam Element - Torsional Rigidity
(OP)
Hello,
When defining the profile for a generalized beam element in Abaqus, it asks for J. In the documentation, J is defined as torsional rigidity. However, from mechanics torsional rigidity is the product of the polar moment of inertia and the shear modulus, GJ. Does the program need J or GJ entered in that area?
Thanks,
Tom
When defining the profile for a generalized beam element in Abaqus, it asks for J. In the documentation, J is defined as torsional rigidity. However, from mechanics torsional rigidity is the product of the polar moment of inertia and the shear modulus, GJ. Does the program need J or GJ entered in that area?
Thanks,
Tom





RE: Abaqus General Beam Element - Torsional Rigidity
What material are analyzing?
RE: Abaqus General Beam Element - Torsional Rigidity
RE: Abaqus General Beam Element - Torsional Rigidity
Be careful when modelling torsional stiffness of concrete sections. If you find after you have performed your analysis that the torsion attracted by the column by modelling 100% of the torsional stiffness (J) exceeds the cracking torsion there will be a large fall away in strength.
The MacGregor textbook on reinforced concrete suggests up to 90% reduction in torsional stiffness after the section has cracked.
I am not to savvy when it comes to modelling higher-order beam elements, but for a tapered section that you have described, I would subdivide the section into smaller sections each with different stiffnesses.