Title: Support Tube Dynamic Analysis
1Support Tube Dynamic Analysis
- KEKs ANSYS simulation
- model details
- Single Point Response Spectrum analysis
- SUGGESTED improvements
- beam model
- Harmonic Response Analysis
- Random Analysis
- Transient Dynamic Analysis (time domain)
E. Doyle 12/6/99
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3KEK model constraints horiz rotations free, all
other d.o.f. fixed
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7Four freq/displacement points used in KEK SPRS
analysis - analysis of max response to
transient event - damping accounted for in
response curve
8Beam Model - simply supported more efficient than
shell model
9Beam Model vs. Shell Model
- Natural frequencies in Hz
10Beam Model - cantilever
11Responses of Concern
- Differential motion between Q1 magnets
- Resulting from
- non-uniform ground motion at two ends
- structure asymmetry
- ANSYS can be used to explore these
- tube support dynamics
- benefit from joining two cantilevers (creation of
common modes)
12Excitation Modes of Concern
- Harmonic - cultural sources
- Harmonic Response Analysis
- Random - natural and cultural sources
- Random PSD (power spectral density)
- Transient Analysis (time domain)
13Harmonic Analysis
- Sinusoidal excitation at specified ampl freq
- Response at magnet mount points
- Combine responses at all frequencies of interest
14Harmonic analysis - vert base motion, unit
amplitude
Different damping for the two beams
15Random Vibration Analysis
- Input PSD of base motion
- Result is PSD response at each magnet
- how to interpret?
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17Absolute PSD Response ( 1m2/hz flat input)
--------- FREQUENCY
18PSD Response relative to base motion
--------- FREQUENCY
19Transient Dynamic Analysis
- Input sampled ground motion (time domain)
- Response is motion in time domain
- Combine in time domain (outside ANSYS)
- Generate cross correlation function (outside
ANSYS)