Figure $1$b A turning machine is set on the middle of a simply supported beam $AB,$ as shown in

Figure la$.$ A free vibration test was performed on this system. The vertical displacement

history at the middle point C of beam AB was obtained and ghown in Figure $lb.$ The

mass of the beam is negligible.

Figure la

Evaluate the findamental natural frequency of the system. How to get more

accurate information about natural frequency$/$frequencies from the vibration test

results?

Evaluate the damping ratio $$ of the system

Determine the dynamic coefficient $H(I)$ at resonance.

Determine the turning speed $n(ru\frac{n}{m}in)$ at resonance.

When the machine runs at $600\frac{r}{m}in,$ the measured amplitude of vibration $($steacly

gtate$)$ at the middle point $C$ is $2$ mm $.$ Determine the amplitude at resonance.

A erming machine is set on the maldle of a simply supportal beats AB$,$ at shown in

Figare $1$a$.$ A frec vieration lest was performed oe this syatern. The vertical displacement

leislory at the midill poine C of beam AB was obtaited and shown in Figure Ib$.$ The

mass of the beam is tegligible.

Evaluate the fixdamental natial frequency of the syokem. How to get etore

acturate information about matural froquencylfriquercies from the vibration test

result?

Evaluale the damping ratio ${?}_5$ of the systert

Detitmine the dyramic cocfficient $H(r)$ at vesteanse.

Detitrine the eurning speod n $($nunimin$)$ al resatanct.

When the machire rans at $600$ rimin, the metiburad amplitule of vibration $($sieady

shatl$)$ at the radale poit C is $2$ rm $.$ Delernine the ampliade at etsonance.

Figure ib