Master Thesis - OUFTI-1
Master Thesis - OUFTI-1
Master Thesis - OUFTI-1
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4.3.5 Application of the global mass smearing method<br />
The second method to be applied is the global mass smearing method. In this method,<br />
the mass of each component is spread out over the entire area of the PCB. So, the global<br />
density is obtained by dividing the mass of the complete electronic card by the volume of<br />
the PCB. This calculation is realized in Equation 4.3.1.<br />
ρ global = m OBC 2 50.4607 × 10−3<br />
= = 3536.1388 kg/m 3 (4.3.1)<br />
V P CB 1.427 × 10 −5<br />
The results are presented in Table 4.4 and in Figure 4.19.<br />
Corresponding modes Frequency deviations (%)<br />
1 21.89<br />
2 30.07<br />
Table 4.4: Frequency deviations between corresponding modes using the global mass smearing<br />
method<br />
Figure 4.19: MAC matrix using the global mass smearing method<br />
It can be remarked that the results are better than the ones obtained using the simple<br />
method. So, this method is more accurate than the preceding one (which is in accordance<br />
with the theory).<br />
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