Experiments of Class 4 open section beams at elevated temperature

• Summary of the current design methods for class 4 cross-section beams at elevated temperature is given.
• Design of beam tests at elevated temperature, as well as full description of the experiments is presented.
• Detailed information about the geometrical data, measured geometrical imperfections, temperature, load and actual mechanical properties were collected.
• Numerical simulations are compared with results of tests.

At elevated temperature, behaviour of Class 1 to 3 open cross-section beams have been investigated experimentally and numerically, whereas for slender Class 4 sections only few experimental data have been collected. Due to the economic assumptions of members with Class 4 cross section and general validity of the existing design rules, further investigation is desired. This paper presents tests and numerical simulation of welded slender (Class 4) I-section beams at elevated temperature. The design of the test set-up, as well as progress of the experiments is presented. Detailed information about the geometrical data, measured geometrical imperfections, temperature, load and actual mechanical properties were collected. The tests were subsequently used for a FE model validation. The described research allows better understanding to the fire behaviour of steel members of Class 4 cross-section beams.