Full scale

Abstract: This paper introduces a new, structural wood-concrete composite system. The system is formed by joining a wood component, such as a floor beam or laminated plate, to a concrete slab utilizing a continuous steel mesh of which one half is glued into a slot in the wood while the other half is embedded into the concrete. Two series of tests were performed and are presented: static push-out tests to establish shear properties of the connector and a full scale bending test with a span of approximately 10 m. Test results reveal that the steel mesh performs favorably—as a stiff yet ductile shear connector between the wood and the concrete. Design equations, per European standards in absence of North American standards are described and used to predict the failure load of the bending test. Calculations indicate that the tested beam performs with near full composite action—specifically, 97% effective stiffness and 99% strength of that of a beam with full composite action. This is a marked improvement in the efficiency of wood-concrete systems developed to date. The system shows itself to be superior to alternative systems in its high structural efficiency as well as being relatively easy to install and economic.

Abstract: Experimental results are presented from a series of tests in a model scale tunnel (1 : 23). This study focuses on single and two-point extraction ventilation systems to complement a previous study with the same apparatus using longitudinal ventilation only. The point extraction ventilation system in this test series was operated under different fire loads and flow conditions of either forced longitudinal ventilation or natural ventilation. Wood crib piles were used to simulate the fire source, which was designed to correspond to a ‘heavy goods vehicle’ fire load at full scale. The parameters varied were the number of wood cribs, the longitudinal ventilation velocity, and the arrangement of the extraction vent openings and their exhaust capacity. Measurement data were obtained for maximum heat release rates, fire growth rates, maximum excess temperatures beneath the ceiling, and heat fluxes. Fire spread between wood cribs with a separation distance corresponding to 15 m at full scale was also investigated. These data are reproduced well by empirical correlations that were established as part of the study. It is concluded that fire and smoke flows upstream and downstream of the fire source can be fully controlled if the ventilation velocities upstream and downstream are above about 2.9 and 3.8 m/s, respectively, at full scale for a single-point extraction ventilation system and greater than about 2.9 m/s on both sides at full scale for a two-point system.

Abstract: Wave tank testing of scaled models is standard practice during the development of floating wind turbine platforms for the validation of the dynamics of conceptual designs. Reliable recreation of the dynamics of a full scale floating wind turbine by a scaled model in a basin requires the precise scaling of the masses and inertias and also the relevant forces and its frequencies acting on the system. The scaling of floating wind turbines based on the Froude number is customary for basin experiments. This method preserves the hydrodynamic similitude, but the resulting Reynolds number is much lower than in full scale. The aerodynamic loads on the rotor are therefore out of scale. Several approaches have been taken to deal with this issue, like using a tuned drag disk or redesigning the scaled rotor. This paper describes the implementation of an alternative method based on the use of a ducted fan located at the model tower top in the place of the rotor. The fan can introduce a variable force that represents the total wind thrust by the rotor. A system controls this force by varying the rpm, and a computer simulation of the full scale rotor provides the desired thrust to be introduced by the fan. This simulation considers the wind turbine control, gusts, turbulent wind, etc. The simulation is performed in synchronicity with the test and it is fed in real time by the displacements and velocities of the platform captured by the acquisition system. Thus, the simulation considers the displacements of the rotor within the wind field and the calculated thrust models the effect of the aerodynamic damping. The system is not able currently to match the effect of gyroscopic momentum. The method has been applied during a test campaign of a semisubmersible platform with full catenary mooring lines for a 6MW wind turbine in scale 1/40 at Ecole Centrale de Nantes. Several tests including pitch free decay under constant wind and combined wave and wind cases have been performed. Data from the experiments are compared with aero-servo-hydro-elastic computations with good agreement showing the validity of the method for the representation of the scaled aerodynamics. The new method for the aerodynamic thrust scaling in basin tests is very promising considering its performance, versatility and lower cost in comparison with other methods.

Abstract: Analyse des essais de reponse a un seisme pseudodynamique de ce type de structure realises en cooperation avec les Etats-Unis et le Japon. On utilise une methode d'analyse dynamique non lineaire pour simuler le comportement observe. La structure est idealisee en cadre plan de trois differents modeles de membrures, on utilise quatre modeles differents d'hysteresis