Rapid screening of fibrous plaster ceilings health status using a laser Doppler vibrometer

The pressing necessity to determine a fast, efficient and rigorous approach to assess the health status of fibrous plaster ceilings across the UK motivated the research presented in this paper. Health monitoring techniques commonly used in the civil engineering sector are generally based on the measurement of the dynamic response of structures, such as buildings or bridges, using sensors (mainly accelerometers). This approach can certainly be adopted for suspended ceiling damage identification studies as well; however, the use of sensors directly connected to the ceiling might be prohibitive and time consuming and, therefore, more suitable for permanent monitoring systems. In this regard, in this study we explore the use of the laser Doppler vibrometer for the rapid screening of fibrous plaster ceilings health status. First, rigorous detailed studies have been conducted in the laboratory to assess damage using an ad hoc manufactured fibrous plaster panel using different sources of excitation in conjunction with the laser vibrometer. Damage indicators for the fibrous plaster ceiling have been introduced and validated through the laboratory experiments. Finally, the proposed approach based on laser vibrometer measurements and damage indicators has been applied to the Institution of Civil Engineers library ceiling in London, UK.