A printed circuit board (PCB), made of fiber reinforced plastic composite material, is attached to a chassis that is attached to a motor vibrating at a speed of \(3000 \mathrm{rpm}\). The PCB can be modeled as a fixed-fixed beam, similar to the one shown in Fig. 9.27, with a length (l) \(20 \mathrm{~cm}\), width \((w) 16 \mathrm{~cm}\), thickness \((t) 0.2\mathrm{~cm}\), mass (m) \(1.0 \mathrm{~kg}\), and Young's modulus \((E)\) \(12.5 \times 10^{9} \mathrm{~N} / \mathrm{m}^{2}\). Determine the following:

a. Stiffness of the PCB

b. Natural frequency of the PCB

c. Displacement transmissibility of the PCB Assume the damping to be negligible.

Figure 9.27:-

Transcribed Image Text:

Chassis of computer PCB Chassis of computer (a) MPCB Frame of car KPCB (b) Frame of car FIGURE 9.27 Chassis of computer fixed to frame of car.