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Predicting Vibration Frequencies of the Diamond Wafer. Presented by: Austin Antoniou Site: Nuclear Physics Mentor: Dr. Richard Jones. Modes of oscillation. Oscillation on the Z axis Rotation About X Axis Rotation About Y Axis Rotation About Z Axis. y. x. z. Model of the diamond.
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Predicting Vibration Frequencies of the Diamond Wafer Presented by: Austin Antoniou Site: Nuclear Physics Mentor: Dr. Richard Jones
Modes of oscillation Oscillation on the Z axis Rotation About X Axis Rotation About Y Axis Rotation About Z Axis y x z
Model of the diamond Wire length=w Tension Forces Diamond length=a Distance between wire joints=s Mass of diamond=m Velocity of a wave traveling on wire=v
Equation Used for Z axis Oscillation(continued) z(y,t)=A+sin(ky-ωt)+A-sin(ky-ωt) z(0,t)=A+sin(-ωt)+A-sin(ωt) z(0,t)=(-A++A-)sin(ωt) z(y,t)=A[sin(ky)cos(ωt)+cos(ky)sin(ωt)+ sin(ky)cos(ωt)-cos(ky)sin] z(y,t)=2Asin(ky)cos(ωt) Where 2Asin(kw)=z0, A=z0/(2sin(kw)) z’(w,t)=z0kcot(kw)cos(ωt) z’(w,t)=kcot(kw) z’(w,t)=kcot(kw)
Equation Used for Z Axis Oscillation(Continued) z’(w,t)=kcot(kw) This equation can be related to the restoring force: FR= -kFTcot(kw)z FR=(d2z/dt2)m=-kFTcot(kw)z (d2z/dbt2)+[-(kFTcot(kw)/m]z=0 The generic equation used for ω isω2=(K/m) In this case, K is equal to Therefore,
Graph ofω2=ωcot(ω) f(ω) (Rad2/s2) ω (rad/s)
Predicted frequencies of the diamond wafer (Hz) (Hz) (Hz) (Hz)
ω2=ωcot(ω) f(ω) (Rad2/s2) ω (rad/s)
What should we make of these calculations? • The higher-frequency oscillations are nearly identical • Mathematically, this is because the slopes of the graphs of the graphs of ω only change slightly from mode to mode • Physically, this is because the system has natural frequencies due to properties such as the length of the wires