Streamlining FE model calculation by reduced model
Challenge: The structural modification analysis of large size FE model requires huge amount of time
Conducting analysis of a large size FE model requires significant amount of time for structural modification analysis because it is necessary to recalculate natural frequencies of whole structural FE model even if the analysis is for limited portion of the FE model.
How to resolve pains:
Replacing the not principal part of the analysis with a low DOF analytical model or modal differential substructure (MDS) can speed up the overall calculation when performing an analytical study using a large-size FE model.
ESTECH.NAST+ makes it easy to create an analytical modal model with basic function and a modal difference structure model with the MDS option which can be used in MSC Nastran.
Strength of the Software
- Modal model is created by FE which makes easy to handle
- Comparing to super element method, no advanced knowhow is required to create model
- Including residual stiffness into joint stiffness generates FE model with high accuracy
MDS is a technique to reduce DOF of FE model by putting the characteristics of non-modified portion on its boundary nodes utilizing output of eigenvalue analysis of the original model when a portion of the whole FE model needs to be modified.
- Comparing to a modal model, it is a big advantage that it is only required to store the results of eigenvalue analysis of an original model and not necessary to define a portion for the structural modification
- FE mesh structure is able to be modified because the model of the structural modification portion is a normal FE model
