Beams with corrugated web at elevated temperature, analytical and numerical models for heat transfer

• Published in: Fire safety journal 2016-11, Vol.86, p.83-94
• Main Authors: Vácha, Jaroslav, Kyzlík, Petr, Both, Ioan, Wald, František
• Format: Article
• Language: English
• Subjects: Aspect ratio; Beams (radiation); Computer simulation; Conduction; Conduction heating; Conductive heat transfer; Corrugated web beam; Corrugating; Elevated temperature; Exposure; Fires; Flanges; Heat transfer; High temperature; Mathematical analysis; Mathematical models; Radiation; Temperature; Temperature effects; View factor
• ISSN: 0379-7112; 1873-7226
• DOI: 10.1016/j.firesaf.2016.09.001

In the case of corrugated web beams, based on experimental results, it was noticed that temperature development along the height of the web has a distinct pattern compared to the flat web beams. The particularity consists of a temperature decrease in the web, in the vicinity of the flange-to-web junction, assigned to the heat transfer by conduction and radiation. On this assumption, starting from the simple relations given in the fire design codes an analytical model is developed considering the heat conduction from the web to the flanges and the radiation heat transfer between web and flanges. The paper presents the results of the proposed analytical method against the experimental results and the numerical simulation. Both analytical and numerical models are compared to the experimental results obtained from the isolated element fire test and the real building fire test. A parametric study on the influence of the geometric dimensions is performed regarding also the time interval for the temperature development. For short term fire exposure, the web exhibits non-uniform temperature along the web height, while for long term fire exposure the entire cross-section tends to a homogeneous temperature. •Analytical and numerical model can predict the nonhomogeneous temperature of the corrugated web.•Beams with high flange-to-web thickness ratio have a greater influence over the temperature development in the web.•The upper and lower part of the web have lower temperatures in the first 15min.•Locally, the flange temperature increase due to conduction exceed the code predicted temperature in the first 15min.