Experimental and finite element analysis of a very large pultruded FRP structure subjected to free vibration

This paper reports field test results to determine the dynamic behavior of a large all-GFRP space-reticular structure. The first experimental results are illustrated in the frame of a wider research aimed to study the dynamic and static performance of an all-GFRP structure built in L’Aquila (Italy), i.e. a temporary shelter to an ancient church collapsed after the earthquake of 6th of April 2009. Free vibrations were given to the structure with an instrumented hammer and recorded by a laser vibrometer. This kind of test gives the possibility to deduce some strategic information upon structural performance in the field of dynamic identification without invasive tests. In the detail the experimental data of the fundamental frequency and period and damping coefficient are here presented, together with displacements deduced. A comparison to a finite element analysis and closed form solutions suitable to structural vibration analysis allows first final considerations in the field of all-GFRP structure to be done.