14 Scaling an OMA Modal Model of a Wood Building Using OMAH and a Small Shaker 153 Fig. 14.1 The test structure Fig. 14.2 Measurement locations and DOFs A total of 12 geophones (Sunfull, PS-4.5B) were installed to monitor vibrations at the six locations given in Fig. 14.2. As shown in Fig. 14.3, each pair of geophones was placed inside a small box which was attached to the load bearing structure at the desired location to measure the dynamic response in x and y. Six ADC cards were provided to operate the 12 geophones. The ADC card has four channels, each with a digital filter (Maxim Integrated, MAX7401), a sample/hold amplifier (Texas Instruments, LF298) and a 24-bit A/D converter (Texas Instruments, ADS1255). An amplification circuit was also employed to amplify the geophone outputs. Among the six ADC cards, a single card was configured as “Master” and used to send out synchronization pulses to the other ones. Additionally, a weather station (Davis Vantage Pro 2) was installed on the roof to measure outdoor temperature, humidity, rain, wind speed and wind direction, and air pressure. A specially designed sensor card was used to acquire data from the weather station.
RkJQdWJsaXNoZXIy MTMzNzEzMQ==