|2-DOF Random Vibration Dashboard.|
|Typical PSD Curve.|
|2 DOF Vibration Model.|
- M1, M2, K01 and K12 are input by the user.
- Modal damping ratio can be input.
- A PSD curve can be input.
- A user defined gravitational constant is input.
- Any consistent set of dimensional units can be used.
- PSD Grms value; the 2 natural frequencies and mode shapes.
- Mode shapes can be animated.
- RMS response G's and relative displacement values.
- A pseudo time series can be determined from the PSD.
- A dynamic transient analysis of the time series can be done and response values determined.
- The transient response can be animated.
|Random Vibration Response.|
For a typical example the following was simulated: a 5 lb circuit board mounted inside a 50 lb box which is mounted to a car frame that has a uniform 5-500 Hz 0.5 G2/Hz random vibration input. Low modal damping of 2% was also assumed. Two scenarios were evaluated.
|Body 2 at 25 Hz and Body 1 Mounted with Varying Stiffnesses.|
The attached spreadsheet summarizes the details shown in the two preceding charts.