I modeled a steel lattice tower in abaqus using line element. i am applying seismic loads and want to delete the elements crossing the yield stress. i tried the same in visualization module --> result --> field output --> status variable, and set to remove elements at a minimum stress of 250 N/mm^2. but it seems that the elements are just hidden, but its stiffness is not reduced to 0. can anyone help me. i am sending my abaqus model.
Element birth and death is little tricky in abaqus. I can explain how to remove the elements from the analysis. Keep on the STATUS of the element. Normally, status has a value of 1 and zero (removed). This value depend upon the value of Damage parameter D. Effective stiffness=DxOriginal stiffness. D starts from zero to 1.If it reached to 1 the element will delete. You can define D via JC fracture criteria. D can change with displacement or fracture energy. Start with the minimum value of displacement corresponds to D=1. It will show deletion of the element.
For more information you can follow documentation (it contains everything related to abaqus)
http://abaqusdoc.ucalgary.ca/v6.9/
Hi
I do not know if this works in Abaqus, but in Nastran the standard trick is to use two identical elements in parallel and a negative Youngs modulus.
When the element is loaded, the second element has a low Youngs modulus. When it should be turned off, you simply give it the same Youngs modulus as the other elemnt but with negative value.
Another way to unload an element would be to use a Multi Point Constraint equation to join relevant nodes. Deleting the MPC would free the element.
/Claes
thank you Vivek Bajpai and Claes Richard Fredö for your support.
what material properties other than density, modulus of elasticity and poisons ratio should i give to the beam element for this analysis?
Is there any example problem available for the same?
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