Mass Scaling Options


Scaling Type	Beginning of the step (fixed mass scaling): Scale the mass once at the beginning of the step for which it is specified. Throughout the step (variable mass scaling): Scale the mass at the beginning of a step and periodically during that step; mass scaling factors will be calculated automatically and applied, as required, throughout the step. Reset the mass matrix: Discontinue all of the mass scaling methods of a prior step.

Fixed Mass Scaling Options


Factor	Mass scaling factor for all elements in the selected supports. Set this option to zero to scale only according to the specified Target Time Increment. If both a Factor and a Target Time Increment are specified, the mass is first scaled by the specified factor and then possibly scaled again, depending on the specified target time increment.
Specify time increment	Adjust mass scaling based on the element stable time increments. Select this option to access the Type and Target Time Increment options.
Type	Uniform: Scale the masses of the elements equally so that the smallest element stable time increment of the scaled elements equals the specified target. Below minimum: Scale the masses of only the elements whose element stable time increments are less than the specified target; the masses of these elements will be scaled so that the element stable time increments equal the specified target. Same time increment: Scale the masses of all elements so that they all have the same element stable time increment equal to the specified target.
Target Time Increment	Desired element stable time increment for the elements in the selected supports. Set this option to zero to scale only according to the specified Factor. If both a Factor and a Target Time Increment are specified, the mass is first scaled by the specified factor and then possibly scaled again, depending on the specified target time increment.


Type	Uniform: Scale the masses of the elements equally so that the smallest element stable time increment of the scaled elements equals the specified target. Below minimum: Scale the masses of only the elements whose element stable time increments are less than the specified target; the masses of these elements will be scaled so that the element stable time increments equal the specified target. Same time increment: Scale the masses of all elements so that they all have the same element stable time increment equal to the specified target.
Target time increment	Desired element stable time increment for the elements in the selected supports.
Select Mode of Mass Scaling Timing	Frequency: Enter the frequency, in increments, at which mass scaling calculations are to be performed during the step. Number interval: Enter the number of intervals during the step at which mass scaling calculations will be performed.