Dear All:
Good day. I have a study case where I want to investigate the response (displacement and velocity) of a Block Foundation with machine (compressor) installed on top of it. I'm aware that I'm going to perform Harmonic Analysis to achieve a graph of 1) displacement amplitude vs frequency and 2) velocity amplitude vs frequency.
Data from compressor includes:
Static Load: 10kN
Unbalance Forces/Couples:
Primary Frequency = 5.0 Hz
Secondary Frequency = 10.0 Hz
1)Primary Vertical: FY=5.0kN Phase= 45 degrees
2)Secondary Vertical: FY=1.0kN Phase= 60 degrees
3)Primary Moment: MY=20.0kNm Phase= -50 degrees
4)Secondary Moment: MY=2.0kNm Phase= 0 degrees
Here's a snippet of my harmonic input:
FINISH
/CLEAR
RESUME,'MODEL','db','.'
/FILNAME,HARMONIC(5.0HZ)
/TITLE,HARMONIC STUDY(f=5.0Hz)
/SOL
ANTYPE,3
HROPT,FULL
HROUT,OFF
LUMPM,0
EQSLV, ,1e-008,
PSTRES,0
!!! Unbalance Forces & Couples
!Motor - Primary
F,999001, FY, 5.0,45
F,999001, FY, 1.0,60
F,999001, MY, 20.0,-50
F,999001, MY, 2.0,0
!Frequency Range & Damping
HARFRQ,0,20,
NSUBST,10,
KBC,1
DMPRAT,0.02,
SOLVE
FINISH
From above information, I would like to seek help from the following:
1) What does the "Primary" and "Secondary" Forces and Moment mean? My understanding is that a Compressor machine comprises of parts rotating at variable speed (for my case some parts rotates in 5.0Hz or 10.0Hz). Am I correct?
2) In my input file, I include all forces/moments together, Is it correct or possible in Harmonic Analysis? As far as I know, according to ANSYS Help file, you can only consider Harmonic Analysis for 1 Frequency only.
3) Do my input file represent my dynamic analysis problem or did i overlook some data or command or syntax?
I would like to humbly seek for enlightenment on above queries.
Kindest regards.
Hanxi
Good day. I have a study case where I want to investigate the response (displacement and velocity) of a Block Foundation with machine (compressor) installed on top of it. I'm aware that I'm going to perform Harmonic Analysis to achieve a graph of 1) displacement amplitude vs frequency and 2) velocity amplitude vs frequency.
Data from compressor includes:
Static Load: 10kN
Unbalance Forces/Couples:
Primary Frequency = 5.0 Hz
Secondary Frequency = 10.0 Hz
1)Primary Vertical: FY=5.0kN Phase= 45 degrees
2)Secondary Vertical: FY=1.0kN Phase= 60 degrees
3)Primary Moment: MY=20.0kNm Phase= -50 degrees
4)Secondary Moment: MY=2.0kNm Phase= 0 degrees
Here's a snippet of my harmonic input:
FINISH
/CLEAR
RESUME,'MODEL','db','.'
/FILNAME,HARMONIC(5.0HZ)
/TITLE,HARMONIC STUDY(f=5.0Hz)
/SOL
ANTYPE,3
HROPT,FULL
HROUT,OFF
LUMPM,0
EQSLV, ,1e-008,
PSTRES,0
!!! Unbalance Forces & Couples
!Motor - Primary
F,999001, FY, 5.0,45
F,999001, FY, 1.0,60
F,999001, MY, 20.0,-50
F,999001, MY, 2.0,0
!Frequency Range & Damping
HARFRQ,0,20,
NSUBST,10,
KBC,1
DMPRAT,0.02,
SOLVE
FINISH
From above information, I would like to seek help from the following:
1) What does the "Primary" and "Secondary" Forces and Moment mean? My understanding is that a Compressor machine comprises of parts rotating at variable speed (for my case some parts rotates in 5.0Hz or 10.0Hz). Am I correct?
2) In my input file, I include all forces/moments together, Is it correct or possible in Harmonic Analysis? As far as I know, according to ANSYS Help file, you can only consider Harmonic Analysis for 1 Frequency only.
3) Do my input file represent my dynamic analysis problem or did i overlook some data or command or syntax?
I would like to humbly seek for enlightenment on above queries.
Kindest regards.
Hanxi