chrono::ChInertiaUtils Class Reference

Description

Utility functions for computations with inertia tensors.

#include <ChMassProperties.h>

Static Public Member Functions
static void	InertiaFromCluster (const std::vector< ChVector3d > &positions, const std::vector< ChMatrix33<> > &rotations, const std::vector< ChMatrix33<> > &Jlocal, const std::vector< double > &masses, ChMatrix33<> &totJ, double &totmass, ChVector3d &baricenter)
	Compute inertia of a cluster. More...
static void	RotateInertia (const ChMatrix33<> inertiaIn, const ChMatrix33<> R, ChMatrix33<> &inertiaOut)
	Rotate an inertia tensor, given a rotation matrix R.
static void	TranslateInertia (const ChMatrix33<> inertiaIn, const ChVector3d dist, const double mass, ChMatrix33<> &inertiaOut)
	Translate an inertia tensor to a non-barycentric reference, given a displacement 'dist', using the Huygens-Steiner parallel axis theorem.
static void	PrincipalInertia (const ChMatrix33<> &inertia, ChVector3d &principal_inertia, ChMatrix33<> &principal_axes)
	Compute principal moments of inertia and the principal axes. More...

Member Function Documentation

InertiaFromCluster()

void chrono::ChInertiaUtils::InertiaFromCluster ( const std::vector< ChVector3d > &  positions, const std::vector< ChMatrix33<> > &  rotations, const std::vector< ChMatrix33<> > &  Jlocal, const std::vector< double > &  masses, ChMatrix33<> &  totJ, double &  totmass, ChVector3d &  baricenter  )

static

Compute inertia of a cluster.

Given a cluster of bodies, each with local inertia tensor, and position and rotation respect to absolute coordinates, compute the total mass, the barycenter and the inertia tensor of the cluster. Notes:

• the resulting total inertia tensor is expressed in absolute coordinates
• we assume that body masses are not overlapping
• we assume that all local inertias are expressed in body local coordinates
• we assume that all local inertias are expressed relative to body barycenter

PrincipalInertia()

void chrono::ChInertiaUtils::PrincipalInertia ( const ChMatrix33<> &  inertia, ChVector3d &  principal_inertia, ChMatrix33<> &  principal_axes  )

static

Compute principal moments of inertia and the principal axes.

The principal moments of inertia are sorted in ascending order. The principal axes are returned as the columns of a 3x3 rotation matrix.

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The documentation for this class was generated from the following files:

• /builds/uwsbel/chrono/src/chrono/physics/ChMassProperties.h
• /builds/uwsbel/chrono/src/chrono/physics/ChMassProperties.cpp