Mapdl.addam(af='', aa='', ab='', ac='', ad='', amin='', **kwargs)[source]#

Specifies the acceleration spectrum computation constants for the

APDL Command: ADDAM analysis of shock resistance of shipboard structures.


Direction-dependent acceleration coefficient for elastic or elastic-plastic analysis option (default = 0).

aa, ab, ac, ad

Coefficients for the DDAM acceleration spectrum equations. Default for these coefficients is zero.


The minimum acceleration value in inch/sec2. It defaults to 2316 inch/sec2 which equals 6g, where g is acceleration due to gravity (g = 386 inch/sec2).


This command specifies acceleration coefficients to analyze shock resistance of shipboard equipment. These coefficients are used to compute mode coefficients according to the equations given in Dynamic Design Analysis Method in the Mechanical APDL Theory Reference. The form of these equations is based on the Naval NRL Dynamic Design Analysis Method. This command, along with the VDDAM and SED commands, is used with the spectrum (ANTYPE,SPECTR) analysis as a special purpose alternative to the SV, FREQ, and SVTYP commands. The mass and length units of the model must be in pounds and inches, respectively.

DDASPEC may alternatively be used to calculate spectrum coefficients.

This command is also valid in PREP7.