### Mass details report

The mass details report calculates and presents the center of mass for
each mass load case together with the total translational and rotational
masses about the center of mass. It is useful for a dynamic analysis if
you need to lump the masses at the center of mass of each floor of a building
or perform calculations that are relative to the center of mass such as
would be required if you wish to take into account the extra torsion due
to accidental eccentricity.

Note that if you wish to obtain the mass details for each floor of your
structure then you should create a filter for each floor and then obtain
a mass details report for each filter.

The total rotational masses include the sum of the individual rotational
masses plus the sum of the translational masses multiplied by their distance
to the centre of mass squared. For example, the total rotational mass
at the center of mass about the Y axis is calculated as follows:

Ry = (R1y + R2y + ... + Rny) + (T1x*d1z2
+ T2x*d2z2 + ... + Tnx*dnz2) + (T1z*d1x2
+ T2z*d2x2 + ... + Tnz*dnx2),

where for mass n, Rny is its Y rotational mass, Tnx & Tnz are its
X and Z translational masses, and dnx & dnz are the X and Z distances
from mass n to the centre of mass.

If
self-weight is included in a mass case then the self-mass of the structure
will also be included in the mass details report and will affect the centre
of mass and other calculations shown in the report.