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Eigen Vector Analysis Control

A nested class within AnalysisControl used to create eigen vector analysis control for dynamic analysis.

Constructor

AnalysisControl.EigenValue(analysis_type = None, ifreq = 1, iiter = 20, idim = 1, tol = 0, frequency_range = None, bstrum = False, bminmax = None, frmin = None, frmax = None, bincnl = False, ignum = None, load_vector = None, vritz = None)

Creates eigen vector analysis control settings for dynamic analysis.

Parameters

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

For EIGEN:

  • ifreq (default=1): Number of Frequencies (required for EIGEN)
  • iiter (default=20): Number of Iterations (required for EIGEN)
  • idim (default=1): Subspace Dimension (optional for EIGEN)
  • tol (default=0): Convergence Tolerance (optional for EIGEN)

For LANCZOS:

  • frequency_range: Frequency Range [frmin, frmax] (optional for LANCZOS)
  • If provided, automatically sets bMINMAX=True
  • Format: [min_freq, max_freq]
  • bstrum (default=False): Sturm Sequence Check (optional for LANCZOS)

For RITZ:

  • bincnl (default=False): Include GL-link Force Vectors (optional for RITZ)
  • ignum: Number of Generations for Each GL-link Force (required for RITZ)
  • load_vector: Load Cases in simple format (required for RITZ)
  • Format: [["case_or_acc", nog], ...]
  • For ground acceleration: ["ACCX"/"ACCY"/"ACCZ", nog]
  • For load case: ["case_name", nog]

Object Attributes

  • ID (int): The ID of the eigen value control entry (always 1).
  • TYPE (str): Type of analysis ("EIGEN", "LANCZOS", or "RITZ").
  • iFREQ (int): Number of frequencies.
  • iITER (int): Number of iterations.
  • iDIM (int): Subspace dimension.
  • TOL (float): Convergence tolerance.
  • bMINMAX (bool): Frequency range flag.
  • FRMIN (float): Minimum frequency.
  • FRMAX (float): Maximum frequency.
  • bSTRUM (bool): Sturm sequence check flag.
  • bINCNL (bool): Include GL-link force vectors flag.
  • iGNUM (int): Number of generations.
  • vRITZ (list): Ritz vector load cases.

Examples

# EIGEN analysis - Subspace Iteration
AnalysisControl.EigenValue(
    analysis_type="EIGEN",
    ifreq=10,
    iiter=20,
    idim=1,
    tol=1e-10
)

# LANCZOS analysis with frequency range
AnalysisControl.EigenValue(
    analysis_type="LANCZOS",
    ifreq=15,
    frequency_range=[0, 1600],
    bstrum=True
)

# LANCZOS analysis without frequency range
AnalysisControl.EigenValue(
    analysis_type="LANCZOS",
    ifreq=12,
    bstrum=False
)

# RITZ analysis with load cases and ground acceleration
AnalysisControl.EigenValue(
    analysis_type="RITZ",
    bincnl=False,
    ignum=1,
    load_vector=[
        ["DL", 1], 
        ["ACCX", 1],
        ["ACCY", 1]
    ]
)