Can ABAQUS do base excitation vibration?
Can ABAQUS do base excitation vibration?
(OP)
Hello All,
Has anyone here experience using ABAQUS to solve base excitation analysis? I'd like to use PSD data as the input excitation to smaller structures on engines which I usually model as a base excitation (i.e. vibration comes through the structure constraints). Can ABAQUS do this? If so what are the basic setup steps?
TIA,
George
Has anyone here experience using ABAQUS to solve base excitation analysis? I'd like to use PSD data as the input excitation to smaller structures on engines which I usually model as a base excitation (i.e. vibration comes through the structure constraints). Can ABAQUS do this? If so what are the basic setup steps?
TIA,
George





RE: Can ABAQUS do base excitation vibration?
Step 1 - a normal modes analysis.
Step 2 -
*psd-definition,name=base,type=base,g=9.807
*step
*random response
*modal damping,structural
*base motion,dof=?,lcase=?
*correlation,psd=base,type=uncorrelated
The above keywords should be all you require.
Incidentally you can take this a step further and use the psd stresses obtained to estimate a fatigue life for the loading cycle input as the psd curve.(using method defined by Bishop+Sherrat. Dirlik then produced an equation which estimates the probability density of rainflow ranges from the psd response. From this curve the fraction of the total test period at a specific stress range can be estimated, and combining this with Miners rule the damage and hence life can be calculated using an S-N curve derived from material constants.) This sounds horrendous but the maths is simple and well within spreadsheet capability.