Sequential analysis is any type of structural analysis performed on a structure under
prior loading (also termed preloading or prestressing).
The response of a structure is affected by its initial state, which is affected by
the preloading/prestressing applied prior to the analysis of interest. Examples of
sequential analysis include analysis of rotorcraft blades under centrifugal
preloading, pillar-like structures under compressive preloading, preload arising
from the pretensioning of bolts on a structure, and so on. Use SimSolid to account for such preloading or prestressing
effects.
You can add or remove loads from sequential analyses to simulate additional loading
or unloading, respectively.
Example
- Structural 1 – Preload
- Immovable 1
- Nut tightening 1
- Structural 2, Linked to Structural 1 – Loading
- Immovable 1
- Nut tightening 1
- Force 1 – 20 N
- Structural 3, Linked to Structural 2 – Unloading
- Immovable
- Nut tightening
- *Force 1 deleted. Editing Force 1 to be 0 N has the same affect.
When the prestressing subcase is linear static, the prestressed stiffness matrix is
given by:
Where,
-
- Prestressed stiffness matrix
-
- Original stiffness matrix
-
- Geometric stiffness matrix that defines the prestressing. This is based
on the stresses of the preloading static subcase.
Depending on preloading conditions, the resulting effect could be a weakened or
stiffened structure.
- If the preloading is compressive, it typically has a weakening effect on the
structure (for example, column or pillar under compressive preloading).
- If the preloading is tensile, it typically has a stiffening effect (for
example, rotorcraft blade under centrifugal preloading).
When the prestressing loadcase is a non-linear static subcase, the prestressed
stiffness matrix
includes the geometric stiffness matrix
, and also accounts for the changes of
due to the converged contact status carried over
from the prestressing loadcase to the prestressed loadcase.
