PSI - Issue 64

Ayaho Miyamoto et al. / Procedia Structural Integrity 64 (2024) 464–475 Author name / Structural Integrity Procedia 00 (2019) 000–000

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3.2. Long-term measurement and automatic data collection system In this section, it is described briefly the bus (vehicle) used for the long-term field test. The long-term measurement using Ube-city's municipal bus routes has been continued by using an in-service fixed-route bus (i.e. a bus actually used to transport passengers) owned by UTB. By using the three-axis acceleration sensor installed under the rear wheel spring of this vehicle, the vibration properties of the bridge being crossed by the bus were extracted as the acceleration response during bridge crossing and deflection was estimated (Miyamoto and Yabe (2012)) . Tables 2 and 3 show the specifications of the bus (vehicle) and the three-axis acceleration sensor installed to the bus, respectively. Figs. 3(a) and (b) show a general view of the Ube-city bus used for the long-term monitoring and the acceleration sensor installed under the rear wheel spring of the bus, respectively.

Table 3. Specifications of three-axis acceleration sensor used for long-term monitoring (vehicle side). Name: Fuji Ceramics SA11ZSC-TI (Three-axis piezoelectric acceleration transducer with built-in amplifier)

Table 2. Specifications of bus (vehicle) used for long-term monitoring.

Item

Specifications

Net vehicle weight Gross vehicle weight Front axle weight

8,130kg 11,485kg 2,730kg 5,400kg

1mV/m/s 2

Charge sensitivity Frequency range Resonant frequency Maximum measurable acceleration Maximum allowable acceleration Power supply for built-in amplifier

1 - 8,000 Hz

Rear axle weight

35 kHz or higher

Wheel base

4.4m

4,000 m/s 2

Table 4. Specifications of GPS sensor.

30,000 m/s 2 or higher

Item

Specifications

GPS sensor ZMP Inc. Survey accuracy 3 m CEP(50%) Frequency performance 5 Hz Sampling frequency 5 Hz

21 - 24 V/0.5 - 10 mA

50 ̶

Temperature range̶

+110˚C

Dimensions

14.2 × 14.2 × 14.2 mm

Mass

Approx. 11.1 g

(b)

(a)

(c)

Fig. 3. (a) General view of Ube-city bus, (b) installed acceleration sensor and (c) package box for automatic data collection system of long term monitoring.