The arm \(A D\) of the excavator shown in Fig. 1.93 can be approximated as a steel tube of outer diameter \(0.25 \mathrm{~m}\), inner diameter \(0.24 \mathrm{~m}\), and length \(2.5 \mathrm{~m}\) with a viscous damping coefficient of \(70 \mathrm{~N}-\mathrm{s} / \mathrm{m}\). The arm \(D E\) can be approximated as a steel tube of outer diameter \(0.18 \mathrm{~m}\), inner diameter \(0.168 \mathrm{~m}\), and length \(1.9 \mathrm{~m}\) with a viscous damping coefficient of \(52 \mathrm{~N}-\mathrm{s} / \mathrm{m}\). Estimate the equivalent spring constant and equivalent damping coefficient of the excavator, assuming that the base \(A C\) is fixed.

Transcribed Image Text:

60 FIGURE 1.93 An excavator. B D -90 B