I have just borrowed Roark's book and it is fine that the calculation mistake have been tackled.
The beam is laminated structure and a large portion of its volume is the epoxy so that the Young's modulus of the experimental beam is much smaller than that of Steel and Aluminium. In this way, it is resonable to obtain a resonance frequency of the beam at 170 Hz. By the way, under the Q factor of about 17, do I need to excitate the beam for 24 hours for the failure of the beam? May I know how to estimate the time of failure?