Ricerc@Sapienza

Aim of the present paper is the analysis of the strain along the beam that is equipped with Glass Fibers Reinforced Polymers (GFRP) with an embedded set of optical Fiber Bragg Grating sensors (FBG), in the context of a project to equip with these new structural elements an Italian train bridge. Different problems are attacked, and namely: (i)during the production process [1] it is difficult to locate precisely the FBG along the reinforcement bar, therefore the following question appears: How can we associate the strain measurements to the points along the bar?

A new era of pollution requires an important focus on the conservation of archaeological sites and monuments. During the last decades, there has been a rising interest in the development of sensors based on optical fibers for several applications, including chemical sensing [1]. An innovative new fiber optic sensor that combines Fiber Bragg Gratings (FBG) coated with pH responsive polymers for monitoring the pH of the rains on critical and prestigious monuments is proposed. In this study, the setup arrangement of the optical sensor is modeled by our own FEM code.

Optical fibers are elements that are mainly used
as a means to transmit light. In this paper, a fiber optic
constituted by a core, a cladding and a Bragg grating in the core
center has been studied. A laser beam with a Gaussian shape is
let to propagate through the core of the fiber with an intensitydependent
refractive index. In the center of the fiber, the
refractive index will reach the highest value, focusing the beam.
This property of the Gaussian beam to a specific intensity