Environmental Testing of a FBG Sensor System for Structural Health Monitoring of Building and Transport Structures

Recently, there has been an increased interest in structural health monitoring (SHM) of building and transport structures. Standard strain gauges placed on a beam surface are mostly used to monitor the mechanical stresses of timber or concrete structures. However, these sensors are susceptible to mechanical damage, electromagnetic interference or negative influences of the measured data during the measurement, such as temperature variations or potential loss of data due to explosive environment. The fibre optic sensor system offers a more suitable and reliable solution – the sensors can be integrated directly into the load bearing structure during its production and thus protected by the construction material against ambient environmental conditions. The first part of this paper presents series of environmental tests of a measuring system based on Fibre Bragg Grating principle performed from 2016 to 2018 in a climate chamber. The chamber can generate defined humidity and/or temperature cycles, which can simulate the behavior of the structure under real environmental conditions. The tested fibre optic sensor system is suitable for load bearing timber (glued laminated timber beams) and concrete structures. In the second part of this paper, mechanical loading tests of glued laminated timber beam with integrated fiber optic sensors performed in 2016, 2017 and 2018 are presented. The article describes the design of test cycles, gives the results of testing, and is concluded with the discussion of given results together with the outline of the future research directions.