**(Eigen Value calculation**) in Finite Element Analysis.

Apart from Lancoz and Guyan's method, SVI method is widely used for modal analysis in FEA application.

This thread will help to understand what are all the steps that takes place behind the solver, when SVI method is used.

**Solution Type :**NORMAL MODE DYNAMICS SVI

**Method : SVI ( SIMULTANEOUS VECTOR ITERATION )**

- Solution type (Restart or No Restart will be determined by the user)
- New Hypermatrix File will be opened
- Completion of Table Formation
- Completion of Boolean Formation
- Begin Partitioning of Constraint
- Begin Mass Matrix Formation
- Mass Partitions Constructed
- Begin Stiffness Matrix Formation
- Stiffness Partitions Formed
- Reaction Force Stiffness Partitions Constructed
- Constraint Elimination Complete
- →Begin Decomposition
- MEMORY ALLOCATED FOR SPARSE MATRIX SOLVER (Sparse solve will be done in-memory)
- MEMORY REQUIRED BY SPARSE MATRIX SOLVER
- COLESKY DECOMPOSITION STATISTICS: will be calculated.
- Determination of SINGULARITY CRITERIA ,NUMBER OF EQUATIONS
- Caluation of MINIMUM CHOLESKY PIVOTS,EQUATION NUMBER, NODE AND DIRECTION
- Calculation of MAXIMUM CHOLESKY PIVOTS,EQUATION NUMBER, NODE AND DIRECTION
- →End Of Decomposition
- Utility Matrices Constructed
- Starting Vectors Formed

→Iteration Number: 1

- Start Of Iteration
- Inverse Power Step Completed
- Stiffness Inner Products Formed
- Mass Inner Products Formed
- Subspace Orthogonalized
- End Of Iteration

→Iteration Number: 2,3,4

- Start Of Iteration
- Inverse Power Step Completed
- Stiffness Inner Products Formed
- Mass Inner Products Formed
- Subspace Orthogonalized
- End Of Iteration

- Modes And Frequencies Obtained

Mode Shapes Expanded

NORMALIZED EFFECTIVE MASSES display for requested modes in X, Y, Z, RX,RY,RZ Direction - Effective Mass Logged
- Analysis Data Preparation Complete

END OF ANALYSIS