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MassMatrix
2D/3D

MassMatrix[bnum] returns the submatrix of the current system mass matrix associated with body bnum.
• The bnum argument can take any of the forms accepted by
Loads to obtain a submatrix associated with multiple bodies.

MassMatrix[All] returns the entire system mass matrix.
Centrifugal[All] + MassMatrix[All] . Acceleration[All] returns the entire dynamic load vector.
• In Modeler3D, if and only if the current solution method is Angular and the current coordinate system is Local will the system mass matrix be a matrix of constants. Otherwise it will generally be a function of Euler coordinates.
• See also: Loads.

Further Examples

Load the Modeler3D package and define a simple model.

Here is the mass matrix of the link body, expressed in Euler parameter space.

Out[3]//MatrixForm=

A change of modeling coordinate system can substantially change the mass matrix expression.

Out[6]//MatrixForm=

See HelpModel3D.