CAE Fidesys 9.0 Documentation

Output of Mass-Inertial Characteristics

In Fidesys, a file with mass centering data is available in the results folder and modal (when calculating modal, dynamic calculations using the superposition method mod) characteristics.

To display modal characteristics in the calculation settings, you must enable option "Calculate effective mass".

Name of this file - PreciseMassSummary.txt

Mass-centering characteristics contain:

• TOTAL MASS - total weight of the model;

• CENTER OF MASS (X, Y, Z) - coordinates of the model’s center of mass relative to given coordinate system;

• ROTATION CENTER (X, Y, Z) - center of rotation of the model relative given coordinate system;

• TOTAL RIGID BODY MASS MATRIX - reduced mass matrix written as:

  
  where:

  • m - body weight;

  • x,y,z - coordinates of the CM of the model, relative to the given system coordinates;

  • I is the inertia tensor of the body relative to a given coordinate system.

• TOTAL INERTIA ABOUT CENTER OF MASS - inertia tensor relative center of mass

Modal characteristics contain:

• PARTICIPATION FACTOR - participation rates;

• EFFECTIVE MASS - effective masses;

• RATIO EFFECTIVE MASS - share component of each effective mass relative to the total mass (moment of inertia);

• CUMULATIVE MASS FRACTION - cumulative value of the share component effective masses relative to the total effective mass;

• RIGID BODY EFFECTIVE MASS MATRIX - reduced matrix of effective mass;

  in appearance this matrix is ​​similar to the reduced mass matrix, but the masses and moments of inertia are the total effective mass along the corresponding global degree of freedom.