Dear Friends,
I am modeling the unstiffened and stiffened plates under pure bending, pure shear, combined bending and shear as shown in the attached file (models 1-5). For the models 1-4, the comparisons of buckling coefficients between FEA and theoretical solutions (or literature results) are very good. However, for the model 5 (the stiffened plate under pure bending), I could not get the same result comparing with theoretical solution.
5 models are used the same plate, modeling procedure and only different applied load and boundary condition at the longitudinal stiffener.
For the model 5, the applied load and boundary conditions are given in the table and figure 5. Instead of modeling longitudinal stiffener, the same boundary condition is imposed in this location ( edge 5 in the table).
I do not know what the problem is for the model 5.
Can any body give me any suggestion for modeling this case?
Thank you so much
For stiffened plates are not uniform and symmetrical again. You can use Donell's theories to model stiffened plates, in which the interaction of beam on the plate can be model as force.
Dear Prof. Weikang Jiang
Could you explain in detail? In this model, I do not model longitdinal stiffener. The same boundary condition is imposed in this location instead of longitudinal as shown in that table (edge 5). Although I tried to model longitudinal stiffener (shell element), I have not yet get the same result with the theoretical solution.
Dear Prof. Claudio Pedrazzi
In this model, I used shell element for modeling the plate. I do not model longitdinal stiffener. The same boundary condition is imposed in this location instead of longitudinal stiffener as shown in that table (edge 5).
I tried to model longitudinal stiffener using shell element, however, it gave me the same result.
The buckling coefficient obtained from model 5 is only higher a little bit than that one of model 1. It is not correct because longitudinal stiffener effects very much on the buckling coefficient of the plate under bending.
So I do not know what the problem is?
Dear Mr. Claudio Pedrazzi
Here is my model in Abaqus for the stiffened plate under bending (the attached file). BC-3 is the boundary condition at the longitudinal stiffener location as shown in line 5 in the table above. Some papers also used the same boundary condition imposed at the stiffener location instead of longitudinal stiffener. However, they did not show me how to apply this boundary condition. In the line 5 of the table above, it is only my opinion.
Actually I use some formula of Timoshenko theory which is used in many papers. I used these formula to verify some models ( unstiffened plate under bending, shear and combined bending and shear ).
Do you have any suggestion?
Thank you very much
Best,
Please upload your Abaqus input file (*.inp).
Otherwise, it will be difficult to answer your request.
Dear Mr. Claudio Pedrazzi
a) In my model, the position of the "stiffener" is placed at the 1/5 of the depth of the plate.
b) I tried to change boundary condition following your suggestion, however, the results change insignificantly.
I also modeled the longitudinal stiffener in my model like your suggestion, however, the result also change insignificantly.
Dear Dr. Nils Wagner
I upload here 3 models:
- Model 1 is the model of the stiffened plate under bending where stiffener is modeled as shell element
- Model 2 is the model of the stiffened plate under bending where stiffener is not modeled and the same boundary condition is imposed instead of stiffener
- Model 3 is the model of the unstiffened plate under bending. This model give the correct value comparing with the theoretical solution.
Models 1 and 2 (stiffened plate) are not correct because the results obtained from these model are quite same with that one of the model 3 (unstiffened plate).
Please help me to check what the problem is with the model 1 and 2
Thank you so much
Best,
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