压电分析中公式R = 0.9/(Ω3)(Co)是怎么推导的?

lyghit

ansys help 里 7.6. Sample Piezoelectric-Circuit Analysis (Batch or Command Method) 节中  R = 0.9/(Ω3)(Co)   的公式是怎么推导的??

To more accurately represent the piezoelectric transducer, include more capacitor-inductor branches in the reduced order model. For example, use nine capacitor-inductor branches as shown in Figure 7.16: "Equivalent Circuit - Harmonic Analysis Near the 3rd Piezoelectric Resonance". The nine Ci-Li (i = 1, 2, ... 9) branches correspond to the first nine resonance modes of the piezoelectric transducer. The equivalent static capacitance and resistance are adjusted to:

Co = Cs - SUM of Ci (i = 1 through 9)

"""""""""""""""""""""R = 0.9/(Ω3)(Co)"""""""""""""""""""

where:

Ω3 = Angular frequency of the third resonance mode