Condition identification of bolted connections using a virtual viscous damper

Vibration-based condition identification of bolted connections can benefit the effective maintenance and operation steel structures. Existing studies show that modal parameters are not sensitive to such damage as loss preload. In contrast, structural responses in time domain contain all information regarding a system. Therefore, this study aims exploit time-domain data directly for connection. Finite element model updating is carried out based on vibration test frame, with various combinations bolts preload, representing different scenarios. It shown match between numerically simulated measured acceleration frame cannot be achieved. The reason time-dependent nonlinearity generated during dynamic excitation frame. To capture nonlinearity, virtual viscous damper proposed. By using proposed alongside updated system matrices finite model, estimated great consistency responses. results demonstrate only estimating each case, but also has potential small just one bolt applied other challenging scenarios identification, where damage.