Temperature effects in composite girder bridges using finite element approach

Abstract

Thermal actions differ from load types considered in the bridge design with a constraining load. A profile of temperature is divided into a uniform part that affect the bridge with a linear expansion and a non-uniform part that will induce shape of the bridge deck. newlineComposite bridge structures to environmental temperature effects is a transient phenomenon as bridges are subjected to daily repeated cycles of solar heating and cooling and ambient temperatures varying with time. newlineDue to diurnal and seasonal changes in the local climatic conditions there is rise and fall in the overall temperature of a bridge structure, referred to as effective bridge temperature, and development of temperature differentials across the depth of cross section is known as thermal gradient or differential temperature. The range of the daily maximum and minimum ambient air temperature affects the effective temperature of the bridge while the solar radiation contributes to the thermal gradients in the bridge cross sections. newlineComposite bridges exposed to environment undergo varying temperatures due to diurnal and seasonal changes in climatic or atmospheric conditions. Temperature distributions in a bridge structure depend upon various environment, meteorological and a bridge parameter. The important environmental parameters influencing the temperature distributions in a bridge structure are intensity of solar radiation, daily range of ambient air temperature humidity, cloud covers, wind speed, turbidity of atmosphere etc. newlineIn addition to these parameters the temperature variation in bridges is also affected by other parameters which includes geographic location of the bridge as governed by the latitude and altitude, geometrical parameters and materials properties of the bridge cross sections. newline newline