Abstract
Correlation of a finite element model with test data is commonly performed. In order to perform these correlation studies, the finite element model may require reduction due to the large size of the model, or the test data may be expanded to the size of the finite element model. Model reduction and model expansion techniques are presented first. Correlation tools typically deployed are then presented. Some additional commentary related to the test data and the correlation process is also provided to give insight into some of the issues that must be faced.
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Abbreviations
- FEM:
-
Finite element model
- EMA:
-
Experimental modal analysis
- SEREP:
-
System equivalent reduction expansion process
- IRS:
-
Improved reduced system
- MAC:
-
Modal assurance criteria
- CoMAC:
-
Coordinate modal assurance criteria
- POC:
-
Pseudo orthogonality check
- CORTHOG:
-
Coordinate orthogonality check
- FRAC:
-
Frequency response assurance criteria
- RVAC:
-
Response vector assurance criteria
- MACCO:
-
Modal assurance criteria contribution
- FRF:
-
Frequency response function
- DOF:
-
Degree of freedom
- NDOF:
-
Full set of “n” finite element DOF
- ADOF:
-
Reduced set of “a” test DOF
- DDOF:
-
Remaining set of “d” deleted or omitted DOF
- [M]:
-
Analytical mass matrix
- [C]:
-
Analytical damping matrix
- [K]:
-
Analytical stiffness matrix
- [U]:
-
Analytical modal matrix
- [I]:
-
Diagonal modal mass matrix
- [Ω2]:
-
Diagonal modal stiffness matrix
- [T]:
-
Transformation matrix
- [E]:
-
Experimental modal vectors
- [D]:
-
Dynamic matrix
- {ẍ}:
-
Acceleration
- {ẋ}:
-
Velocity
- {x}:
-
Displacement
- {F}:
-
Force
- {p}:
-
Modal displacement
- {u}:
-
Modal vector
- {ei}:
-
ith experimental modal vector
- {uj}:
-
jth analytical modal vector
- ek:
-
kth degree of freedom of the experimental modal vector
- up:
-
pth degree of freedom of the analytical modal vector
- n:
-
Full set of finite element DOF
- a:
-
Tested set of experimental DOF (also master/active DOF)
- d:
-
Deleted (omitted) set of DOF
- S:
-
Static condensation
- I:
-
IRS condensation
- f:
-
Dynamic condensation
- U:
-
SEREP condensation
- H:
-
Hybrid condensation
- k,p:
-
Degree of freedom identifiers
- i,j:
-
Mode identifiers
- T:
-
Transpose
- g:
-
Generalized inverse
- −1:
-
Standard inverse
- *:
-
Conjugate
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Avitabile, P., Mains, M. (2022). Finite Element Model Correlation. In: Allemang, R., Avitabile, P. (eds) Handbook of Experimental Structural Dynamics. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-4547-0_17
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DOI: https://doi.org/10.1007/978-1-4614-4547-0_17
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