Overview

The SHED group has a suite of test equipment available to carry out structural dynamics testing (Facilities). Such equipment can be used for vibration/structural monitoring and modal analysis of structures at a range of scales in both the laboratory and field.  Such equipment includes modal shakers, impact hammers, sensors (e.g. accelerometers), data acquisition hardware and data software.

In forced vibration testing, more commonly known as an Experimental Modal Analysis (EMA), the structure is vibrated by artificial means for example using an impact hammer (or a mass shaker) under a known input force. The input force and output response are recorded and used to calculate the modal parameters of the structure under test. Both numerical methods (e.g. using Finite Element Analysis, FEA), and experimental techniques are used when possible for the modal analysis, with the latter generally used to validate the modelling results.  

Similar testing has been carried out in the field on the pier at Ballinskelligs, Co. Kerry and a dolphin jetty at SSE thermal Tarbert, on the Shannon Estuary in Tarbert, Co. Kerry .

Examples of recent testing include vibration monitoring on a scaled model (1:50) of a concrete pier structure in the LiR’s wave watch flume tank (pictured below), where accelerometers are attached to the surface of the model and the excitation force and loading is provided by controlled simulated waves which strike the face of the model.