RESUMEN
The primary purpose of this paper is to investigate the possibility of using a Full Flight Simulator (FFS) as an experimental setup for passengers' comfort analysis. Results based on subjective measurements are thus presented to assess comfort levels experienced during a simulated flight. A preliminary investigation has been conducted on a sample of 125 candidates to gain insight into the elements influencing the comfort level perceived based on the participants' actual flight experience; this suggested that the seat configuration is of great importance. Then, the experiment carried out by means of the FFS have been conducted on a reduced sample of 20 candidates for economic and organizational reasons. The behaviour of the 65% of the candidates has been analysed in a seating configuration comparable to the seat of a business-class aircraft. While the experience of the remaining 35% has been studied in an economy-type seat arrangement. Although the main variable under consideration was the seat, several environmental parameters were also considered during the experimental tests to evaluate their effects on perceived comfort level. During each simulated flight, passengers have been subjected to different levels of light intensity, noise, temperature and vibration associated with the different flight phases. Subjective data were collected using a questionnaire concerning every parameter and submitted to the passengers for each flight phase. The aim of varying the environmental parameters inside the cabin was to look for a relation between the subjective comfort level and each comfort parameter. In addition to perceived comfort based on the questionnaire, statistical analysis with parametric and non parametric tests revealed significant effects of environmental variables.
RESUMEN
The increasing development of smart materials, such as piezoelectric and shape memory alloys, has opened new opportunities for improving repair techniques. Particularly, active repairs, based on the converse piezoelectric effect, can increase the life of a structure by reducing the crack opening. A deep characterization of the electromechanical behavior of delaminated composite structures, actively repaired by piezoelectric patches, can be achieved by considering the adhesive layer between the host structure and the repair and by taking into account the frictional contact between the crack surfaces. In this paper, Boundary Element (BE) analyses performed on delaminated composite structures repaired by active piezoelectric patches are presented. A two-dimensional boundary integral formulation for piezoelectric solids based on the multi-domain technique to model the composite host damaged structures and the bonded piezoelectric patches is employed. An interface spring model is also implemented to take into account the finite stiffness of the bonding layers and to model the frictional contact between the delamination surfaces, by means of an iterative procedure. The effect of the adhesive between the plies of piezoelectric bimorph devices on the electromechanical response is first pointed out for both sensing and actuating behavior. Then, the effect of the frictional contact condition on the fracture mechanics behavior of actively repaired delaminated composite structures is investigated.