Experimental and finite element investigation of temperature distributions in concrete-encased steel girders

Abstract

SummaryThe structural performance of bridge structures is temporal and is mainly controlled by the types of the applied loads. To continuously observe the structural performance of bridges, structural health monitoring sensors that include among many temperature sensors are used. The impact of nonuniform temperature distributions in bridge girders due to the environment thermal loads has been recognized by former researchers and bridge design codes. To evaluate these and other effects on the structural behavior of bridge structures, many field and experimental structural health monitoring studies were carried out. However, more researches are required to investigate the temperature distributions in other girder configurations. This work is directed to investigate the impact of air temperature and solar radiation on temperature gradient distributions in concrete-encased composite girders. For this purpose, an experimental concrete-encased steel girder segment was instrumented with thermocouples and other sensors. The experimental data recording continued for 6 months during the hot and cold seasons. Furthermore, a thermal finite element (FE) parametric study was conducted to investigate the effect of the girder size. The test results showed that the vertical and lateral temperature gradient distributions and the variation of the temperature gradients with time are controlled by the amount and location of the received solar radiations. The FE analysis showed that the daily temperature variations are higher in smaller girders, whereas the temperature gradients are smaller than in larger girders. Moreover, the FE results showed that the thickness of the girder's concrete members has an important impact on temperature gradients and temperature distributions.

Temperature Field Boundary Conditions and Lateral Temperature Gradient Effect on a PC Box-Girder Bridge Based on Real-Time Solar Radiation and Spatial Temperature Monitoring

“…The maximum measured and simulated temperature difference on the top slab reached 4.0 °C. Overall, the 3D FE model can be considered suitable for simulation of thermal conductivity, heat convection, ambient temperatures, and solar radiation in the box girder [ 6 , 8 , 11 , 14 ]. The difference between the measured and FE simulated temperature values may be attributed to the assumptions made in FE analysis that the heat thermal conductivity and the absorption rate are uniform in the structure.…”

“…They proposed empirical equations to predict the maximum vertical and lateral temperature gradients based on the data collected [ 5 ]. The same approach was applied to concrete-encased steel girders [ 6 ]. Taysi and Abid investigated the effects of the thermal properties in a full-scale concrete box-girder segment.…”

“…Empirical equations were developed based on the given temperature data, hence they may not be applicable for a different on-site situation. Some studies used pyranometers to measure the intensity of solar radiation and thermocouples to measure the temperature distributions [ 5 , 6 , 7 ]. However, only the radiation intensity on the top flanges was investigated, while the effect of the flange shadow casting on the web was not discussed.…”

Vibration‐based damage localization with load vectors under temperature changes

“…Especially varying temperature may affect damage features far more significantly than local structural damage in early stage . The temperature distribution may be nonuniform over the structure . To eliminate those damage masking effects, different concepts have been proposed in the last decades.…”

Experimental Investigation of Thermal Response of Encased Composite Beams

“…Several experimental researches were conducted to evaluate the thermal response of concrete beams [2][3][4][5][6][7][8], while other experimental researches were directed to study these effects on steel beams [9][10][11]. However, the experimental researches that investigate the effect of the atmospheric thermal loads on composite beams are few in the literature [12]. In this research, an experimental concrete-encased-steel composite beam was constructed in an open environment to study the thermal response of such type of beams under the atmospheric thermal loads.…”