diff options
Diffstat (limited to '3532/CH3/EX3.5')
| -rw-r--r-- | 3532/CH3/EX3.5/Ex3_5.sce | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/3532/CH3/EX3.5/Ex3_5.sce b/3532/CH3/EX3.5/Ex3_5.sce new file mode 100644 index 000000000..f5f515bd1 --- /dev/null +++ b/3532/CH3/EX3.5/Ex3_5.sce @@ -0,0 +1,21 @@ +clc
+clear
+mprintf('Mechanical vibrations by G.K.Grover\n Example 3.4.1\n')
+//given data
+J=0.06 //moment of inertia of disc of pendulum in Kg-m^2
+G=4.4*10^10 //rigidity modulus in N/m^2
+l=0.4 //lenght of shaft in m
+d=0.1 //diametre of shaft in m
+a1=9 //amplitude of first oscillation in degrees
+a2=6 //amplitude of second oscillation in degrees
+a3=4 //amplitude of third oscillation in degrees
+//calculations
+delta=log(a1/a2) //logarithmic decrement eqn 3.4.1 explained in sec 3.4
+zeta=delta/sqrt(4*%pi^2+delta^2) //representing zeta from eqn 3.4.1 in sec 3.4
+Kt=(G/l)*(%pi/32)*d^4 //(%pi/32)*d^4 is the section modulus
+C=zeta*2*sqrt(Kt*J) // torsional damping coefficient which is the damping torque at unit velocity (similar to eqn 3.3.6 in sec 3.3)
+Wn=sqrt(Kt/J) // undamped natural freq in rad/sec
+T=2*%pi/(sqrt(1-zeta^2)*Wn) //periodic time of vibration
+fn=Wn/(2*%pi) //natural freq of undamped vibration
+//output
+mprintf(' a)logarithmic decrement is %4.4f\n b)damping torque at unit velocity is %4.4f N-m/rad\n c)periodic time of vibration is %4.5f sec\n frequency of vibration if the disc is removed from viscous fluid is %4.4f Hz',delta,C,T,fn)
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