Mass and Temperature Changes in Operational Modal Analysis

Dynamic testing and analysis of the world's first metal 3D printed bridge

“…This technique allows the modal parameters of civil structures to be estimated using ambient vibration measurements over short time intervals, allowing changes in dynamic parameters to be tracked over time. By tracking changes in the dynamic parameters, the impact of time-variant modal behaviour can be quantified, allowing for a more accurate assessment of serviceability performance and diagnosis of the causes of differences in behaviour between the design and the structure [36][37][38].…”

“…The majority of OMA methods assume that the dynamic response of the system to a known input is constant over time, neglecting the impact that time-variant modal behaviour may have on estimates of dynamic parameters. To overcome the shortcomings of existing OMA techniques, the short-time random decrement technique (ST-RDT), a time-domain OMA method, has been developed by the authors [36][37][38]. The ST-RDT is an expansion on the random decrement technique [44], and allows variations in a structure's dynamic properties to be tracked over time by dividing the measured acceleration of a structure into short windows of data.…”

“…Modal parameters are estimated from the RDS using the matrix pencil method [41]. For further details on the application of the ST-RDT see Wynne et al [37].…”