416
Y. Xu et al.
Fig. 36.3 The loading curve
Pressure
Time
4.0 MPa
20 min
36.2.4 Parameter Setting of Acquisition and Data Analysis
Display
There is no conical shell positioning software in our AE detection system. In order
to locate the sound sources more accurately, we expand the external conical shell
into a sector plan, as shown in Fig. 36.4. D1 and D2 in Fig. 36.4 are the outer shell
diameters at the first circle of sensors (1#–4#) and the third circle of sensors (9#–16#)
respectively, and H is the vertical height between the first and third circles of sensors.
As can be seen from the figure,
D1/D2 = X/(X + H), that is, X = D1 × H/(D2 − D1)
π × D1 = 2π × X × θ/360, that is, the center angle θ of the sector circle is 180
× (D2 − D1)/H.
D1, D2 and H can be measured on site, so after getting θ, the plane coordinates
of each sensor can be calculated further and then entered into the positioning setup.
According to the test of background noises, the lower threshold is selected. The
wave velocity is measured several times on the conical shell, and the average value
Fig. 36.4 The conical shell
and its expanded sector plan
Y. Xu et al.
Fig. 36.3 The loading curve
Pressure
Time
4.0 MPa
20 min
36.2.4 Parameter Setting of Acquisition and Data Analysis
Display
There is no conical shell positioning software in our AE detection system. In order
to locate the sound sources more accurately, we expand the external conical shell
into a sector plan, as shown in Fig. 36.4. D1 and D2 in Fig. 36.4 are the outer shell
diameters at the first circle of sensors (1#–4#) and the third circle of sensors (9#–16#)
respectively, and H is the vertical height between the first and third circles of sensors.
As can be seen from the figure,
D1/D2 = X/(X + H), that is, X = D1 × H/(D2 − D1)
π × D1 = 2π × X × θ/360, that is, the center angle θ of the sector circle is 180
× (D2 − D1)/H.
D1, D2 and H can be measured on site, so after getting θ, the plane coordinates
of each sensor can be calculated further and then entered into the positioning setup.
According to the test of background noises, the lower threshold is selected. The
wave velocity is measured several times on the conical shell, and the average value
Fig. 36.4 The conical shell
and its expanded sector plan