Name: Arhum Ahmed
Roll no: ME-19248
Exercise Lab#3
the original condition as prescribed by the manual we get:
Effect of Masses M1 & M2:
By increasing the mass M1 to 2250kg, we have observed that in the position w.r.t time increases, and speed w.r.t
time decreases. On increasing mass, the damping effect reduce and wavelength increases.
While doing the same on mass M2 we have same graph of vb as compared to that of M1 of 2250Kg if we take
everything constant the changes occur in the second graph as shown below,
By decreasing the mass M1 to 250Kg, we have observed that the position w.r.t time decreases, and the speed w.r.t
time increases. On decreasing mass, the damping effect is rapid and wavelength reduces.
While doing the same on mass M2 we have same graph of vb as compared to that of M1 of 250Kg if we take
everything constant the changes occur in the second graph as shown below,
Name: Arhum Ahmed
Roll no: ME-19248
Effect of Friction Co-efficient B1, B2 & B3:
When we increase the B1 from 20 to 60N.sec/m we observe amplitude decreases for both the graphs, while
wavelength remain same and graph damps out fast.
When we increase B2 from 20 to 60N.sec/m we observe amplitude decreases for both the graphs, while
wavelength increases and graph damps out fast. But in comparison with the graph of B1=60 we see that the
damping effect is less while amplitude is more and wavelength remain same.
When we increase B3 from 30 to 90N.sec/m we see a different graph all over as that graph overshoots at the end
here the highest amplitude is much more higher than the original graph. While wavelength is same and system
does not seem to damp out. While it is increasing at the end.
Effect of Stiffness K1 & K2:
When we increase K1 from 15 to 45N/m amplitude of both the graph decrease while wavelength also decrease for
both the graphs. Also systems damps out
Name: Arhum Ahmed
Roll no: ME-19248
When we increase K2 from 15 to 45N/m amplitude of both the graphs are same like wise of “K1” but system
further damps out fast and graph of “va/xa” has same wavelength like the original one and “vb/xb” has
wavelength same as of “K1’s “ ”vb/xb”.
Effect of Applied Force:
When we increase the applied force from 300N to 900N we see a graph that is approximately same as that of the
original one but it has higher amplitudes due to more force. So it relates that force and amplitudes have direct
relation.
Conclusion:
We concluded that:
1) Force increases amplitude only.
2) Most damping occurs from the stiffness.
3) As B3 friction is directly connected that’s why we are getting overshoots at the end.
4) Damping decreases in every case except that of B3 where it is increased in 200 time-step while applied
force doesn’t effect damping.