Shell Stiffness
The Shell - Stiffness dialogue lets you scale individual components of the shell-stiffness matrix for different analysis types.
Following tools provide this dialogue:
- Plane plate
- Plane wall
- Foundation slab
- Shell model - for beams and columns when converted to shells
When you open the Stiffness tab, the following window appears.
Calculations
- Same for all calculations - when checked, the connection uses the same settings for all calculations
- Calculation type - drop-down list that available when the checkbox is unchecked. Lets you select a specific calculation type and define unique parameters for each
- Copy to - copies the settings from the current calculation type to one or more other calculation types
Stiffness modifier factors
Enter reduction (or amplification) factors for each component of the shell stiffness matrix D and shear matrix H. A value of 1.0 leaves the component unchanged.
| Factor | Matrix term | Behaviour |
|---|---|---|
| r1 | Bending (1,1) | Bending around local y′ |
| r2 | Bending (2,2) | Bending around local x′ |
| r3 | Bending (1,2) | Coupling between bending axes |
| r4 | Membrane (1,1) | Axial stiffness along x′ |
| r5 | Membrane (2,2) | Axial stiffness along y′ |
| r6 | Membrane (1,2) | In-plane shear coupling |
| r7 | Shear (1,3) | Transverse shear along x′-z′ |
| r8 | Shear (2,3) | Transverse shear along y′-z′ |
Stiffness matrix info
Click the i › button to open an information window that displays the formulas for full stiffness matrices and highlights where each r factor is applied within the formulas.