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Eigen Value Analysis Control

A nested class within AnalysisControl used to define Eigen Value Analysis control for dynamic analysis.

Constructor

AnalysisControl.EigenValue(analysis_type = None, nFreq = 1, nIter = 20, nSubspaceDim = 1, tol = 1e-10, frequency_range = [None,None], bStrum = False, load_Vectors = None, nGL_LinkVectors = 0)

Creates eigen vector analysis control settings for dynamic analysis.

Parameters

  • analysis_type: Type of Analysis (required)
    1. "EIGEN": Subspace Iteration
    2. "LANCZOS": Lanczos
    3. "RITZ": Ritz Vectors

For EIGEN:

  • nFreq (default=1): Number of Frequencies (required for EIGEN)
  • nIter (default=20): Number of Iterations (required for EIGEN)
  • nSubspaceDim (default=1): Subspace Dimension
  • tol (default=1e-10): Convergence Tolerance

For LANCZOS:

  • nFreq (default=1): Number of Frequencies (required for LANCZOS)
  • frequency_range: Frequency Range [frmin, frmax]
  • Format: [min_freq, max_freq]
  • bstrum (default=False): Toggles Sturm Sequence Check

For RITZ:

  • load_Vectors: Load Vectors definition (required for RITZ)
  • Format: [["case or acc", num_generations], ...]
  • For ground acceleration: ["ACCX"/"ACCY"/"ACCZ", num_generations]
  • For load case: ["case_name", num_generations]
  • nGL_LinkVectors (default=0): Number of generations for each GL-link. If value = 0 , then GL-link force vector won't be included.

Examples

# EIGEN analysis - Subspace Iteration
AnalysisControl.EigenValue('EIGEN',
            nFreq=33,
            nIter=21,
            nSubspaceDim=3,
            tol=1e-12
            )

# LANCZOS analysis without frequency range
AnalysisControl.EigenValue('LANCZOS',
            nFreq=33,
            bStrum=True
            )

# LANCZOS analysis with frequency range
AnalysisControl.EigenValue('LANCZOS',
            nFreq=33,
            frequency_range=(5,100),
            bStrum=True
            )


# RITZ analysis with load cases and ground acceleration

# Sample Load Case is created
Load_Case('USER','DL')
Load_Case.create()

AnalysisControl.EigenValue('RITZ',
            load_Vectors=[('ACCX',6),('ACCY',7),('DL',4)],
            nGL_LinkVectors=0
            )