Reaction forces in the middle of a plate

[cranaero09]

Dear All,

I am modelling an half plate symmetry and I want to know the reaction forces in the centre of this plate. However I can not find them because are all zero. Is there any possibility to find the reaction forces between the elements in a plate?


If I a quarter of the plate then I will have my reaction forces in the crack propagation line(see the attachment) but in my case I will need to model only half plate.


Please let ma know if you can give me any support in this,
Many thanks,
Cranaero09

 

[UMEngineer]

When you defined your symmetry. How did you do that? Was it an Axissymmetric model, or did you model half and use a symmetric boundary condition. If you split it half way down the, say the XY plane, You would want U3=UR1=UR2=0 if I remember right. Which is ZSYMM in the list. That should make those stresses non-zero. Thats just an assumption, my experience with modeling symmetry is poor at best.

 

[cranaero09]

The symmetry is on one axis and I did that by applying the boundary conditions. I do not have problem with that. My problem is how can I see the reaction forces and the reaction moment inside the plate.

Thanks

 

[corus]

You won't see reaction forces in the middle of the plate as reaction forces only occur at restraints. The nodal forces inside the plate will, of course, sum to zero, but if you remove some of the elements using tools/display options then you may be able to see the nodal forces on one side.
The model, incidentally, was unable to load on my pc after the conversion to 6.8-1.

corus

 

[cranaero09]

Hi corus

thanks for the advice but I still can not get the forces at the nodes. I create a group of nodes but I can not see the nodal forces. How is it called the variables for the nodal fore in ABAQUS? I send you the input file this time. Hope it will work. The version of my ABAQUS is 6.7.
Thanks for replying,

cranaero09

 

[corus]

You can plot the element forces NFORC1, NFORC2 etc. Look in the results/field ouput option.

Why such a fine mesh in the middle of the model when nothing happens there?

corus

 

[cranaero09]

Hi corus,

I have checked the nodal forces NFORC1 and NFORC2 but the value are still zero. The mesh in the middle is very fine because I am going to propagate a crack in there.

Thanks again.

 

[corus]

Strange, when I plot NFORC2 and query the values at the centre line then it shows values of about 42. Values vary across the whole area of the plate.

corus

 

[cranaero09]

Corus,

I have put in the file attached the nodal forces but NFORC2 are still zero in the middle of the plate. You can check for the example the node 5 or 208 and 209 which are on the centre and the value are zero. Is there something that I am doing wrong? how did you get to the values 42?

Thanks again