jdhai001
Mechanical
- Mar 27, 2010
- 1
thread727-23465
I have a 3 bay wing box to which the lower panel of the middle bay is removed. I have done the hand calculations and I am trying to verify with NX Nastran using:
-Shear elements CSHEAR with F1 and F2 equal to zero (or very close to zero 0.000001)
-Rods elements CRODS to add stiffnes to the side of the shear panels.
The 2 bay wing box is fixed at one end and free at the other.
At the free end a torque is applied.
The issues I am having are:
1-Results changes with different mesh sizes on shear panels
2-Results change as I modifies the area of the rods.
To my understanding the rods should carry all bending loads and shear panels only subjected to shear. After a certain area of the rods the wing box should be rigid enough (to carry all bending) to only transfer shear into the panels. No matter how stiff I make the Rods the shear flows changes.
If I keep everything the same and I only change the mesh size the shear flows change as well.
Anyone has any idea of what may be the issue.
I have a 3 bay wing box to which the lower panel of the middle bay is removed. I have done the hand calculations and I am trying to verify with NX Nastran using:
-Shear elements CSHEAR with F1 and F2 equal to zero (or very close to zero 0.000001)
-Rods elements CRODS to add stiffnes to the side of the shear panels.
The 2 bay wing box is fixed at one end and free at the other.
At the free end a torque is applied.
The issues I am having are:
1-Results changes with different mesh sizes on shear panels
2-Results change as I modifies the area of the rods.
To my understanding the rods should carry all bending loads and shear panels only subjected to shear. After a certain area of the rods the wing box should be rigid enough (to carry all bending) to only transfer shear into the panels. No matter how stiff I make the Rods the shear flows changes.
If I keep everything the same and I only change the mesh size the shear flows change as well.
Anyone has any idea of what may be the issue.
