Massprop command in AutoCAD

Massprop command in AutoCAD – Calculate the mass properties for Solid

The way to call Massprop command in AutoCAD

Scroll down menu	Screen menu	Type command	Tool bar
Tools » Inquiry » Region/Mass Properties	Tools1 » Massprop	Massprop	Inquiry

Massprop command calculates the mass properties of the selected region or 3D solids, including: Mass, Volume, Bounding box, Centroid, Moments of inertia, Products of inertia, Radii of gyration, Principal moments and X,Y,Z directions about centroid,…

The properties that Massprop command displays depend on the selected object Regions in XY plane of current UCS or Solids.

Regions

Below are mass properties which are displayed with selected regions:

Area Area of solids surfaces or area of regions
Perimeter Whole length of internal and external perimeter of regions. The perimeter of solid is not calculated.
Bounding box 2 coordinates define bounding box. With the regions are coplanar with XY plane of current UCS, bounding box is defined by the cross opposite angles of rectangle which creates regions. With the regions are not coplanar with XY plane of current UCS, bounding box is defined by the cross opposite angles of 3D box which creates regions.

Centroid 2D or 3D coordinates is the area center of regions. With the regions are coplanar with XY plane of current UCS, this coordinate is 2D point. With the regions are not coplanar with XY plane of current UCS, this coordinate is 3D point.

Massprop command in AutoCAD – Calculate the mass properties for Solid

If the regions are coplanar with XY plane of current UCS, the following mass properties appear:

Moments of inertia: Moment of inertia
Products of inertia: Products of inertia is used to define the force making the move of object.
Radii of gyration: Radii of gyration is the other way of moment of inertia of solid.
Principal moments and X,Y,Z directions about centroid: Principal moments receives from products of inertia and has the same value of unit. Moment of inertia is highest when it is across an axis at the centroid of object. Moment of inertia is lowest when it is across the second axis which is perpendicular with the first axis and is also across the centroid. The third value is at between the highest and lowest value.

Solids

Below are mass properties which are displayed with selected solids:

Mass Mass
Volume Volume of 3D solid object.
Bounding box The across opposite angles of 3D solid box
Centroid Centroid of 3D solid block.
Moments of inertia: Moment of mass inertia is used to calculate rotation force of object around an axis.
Products of inertia Products of inertia is used to define the force making the move of object.
Radii of gyration Radii of gyration is the other way of moment of inertia of solid.
Principal moments and X,Y,Z directions about centroid Principal moments

Massprop command in AutoCAD – Calculate the mass properties for Solid

Parameters to calculate following to current UCS

Below are parameters controlling units which mass properties are calculated:

Density Calculate mass of solid.
Length Calculate volume of solid.
Length*length Calculate are of regions and area of faces of solid.
Length*length*length Calculate bounding box, radii of gyration, centroid and perimeter.
Density*length*length Calculate moment of inertia, products of inertia and principal moments.

Massprop

Select objects: Select solids object (1) and region (2) to view mass properties

—————- REGIONS —————-
Area: 17473
Perimeter: 817
Bounding box: X: 377 — 664
Y: -65 — 170
Z: 21 — 21
Centroid: X: 521
Y: 53
Z: 21
—————- SOLIDS —————-
Mass: 527630
Volume: 527630
Bounding box: X: 68 — 188
Y: -5 — 63
Z: 0 — 85
Centroid: X: 128
Y: 29
Z: 43
Moments of inertia: X: 1960358657
Y: 10782059082
Z: 10198590702
Products of inertia: XY: 1978925981
YZ: 655043543
ZX: 2881895487
Radii of gyration: X: 61
Y: 143
Z: 139
Principal moments and X-Y-Z directions about centroid:
I: 556621403 along [1 0 0]
J: 1121744169 along [0 1 0]
K: 1042408813 along [0 0 1]

Write analysis to a file? [Yes/No] <N>: Enter Y or N, or press

If you enter Y, Massprop command reminds you to enter file name. The default extension part of this file is .mpr, but it is text file which can be opened by any text edit.