Dynamic Effects of Turbulent Crosswind on the Serviceability State of Vibrations of a Slender Arch Bridge Including Wind-Vehicle-Bridge Interaction

The use of high-performance materials in bridges is leading to structures that are more susceptible to wind- and traffic-induced vibrations due to the reduction in the weight and the increment of the slenderness in the deck. Bridges can experience considerable vibration due to both moving vehicles and wind actions that affect the comfort of the bridge users and the driving safety. This work explored the driving safety and comfort in a very slender arch bridge under turbulent wind and vehicle actions, as well as the comfort of pedestrians. A fully coupled wind–vehicle–bridge interaction model based on the direct integration of the system of dynamics was developed. In this model, the turbulent crosswind is represented by means of aerodynamic forces acting on the vehicle and the bridge. The vehicle is modeled as a multibody system that interacts with the bridge by means of moving contacts that also simulate road-surface irregularities. A user element is presented with generality and implemented using a general-purpose finite-element software package to incorporate the aeroelastic components of the wind forces, which allows modeling and solving of the wind–vehicle–bridge interaction in the time domain without the need for using the modal superposition technique. An extensive computational analysis program is performed on the basis of a wide range of turbulent crosswind speeds. The results show that bridge vibration is significantly affected by the crosswind in terms of peak acceleration and frequency content when the crosswind intensity is significant. The crosswind has more effect on the ride comfort of the vehicle in the lateral direction and, consequently, on its safety in terms of overturning accidents

‘Friends call me racist’: Experiences of repercussions from writing comments on newspaper websites

acceptedVersio

Algekulturteknologi. Eksperiment- og produksjonsanlegg for mikroalger i Vestfold. Delrapport 4: Algetyper, anvendelsesområder og forretningsmuligheter

Årsliste 1999Algedyrking med kommersiell interesse er tema. Mikroalger som benyttes til massedyrking og produkter som fremstilles er behandlet. Det blir gitt en oversikt over forutsetninger for algekulturteknologi i Vestfold. Produksjon av algebiomasse er tenkt utført i industrianlegg, eller i veksthusbaserte dyrkingsanlegg. Kommersielt interssante produkter omfatter fôr til husdyr og organismer i akvakultur, helsekost/tilsetningsstoffer i mat, og medisinske handelsvarer. Synergimuligheter ved samlokalisering med akvakulturanlegg eller veksthusanlegg for planteproduksjon blir vurdert. Faglige og praktiske forutsetninger for valg av lokalitet for et pilotanlegg i Vestfold blir drøftet. Ut fra vektlegging av spesielle praktiske forutsetninger blir det foreslått å prioritere Slagentangen (ESSO Norge A/S) til formålet.Norges forskningsråd (NFR) - FoU-programmet KLIMATE