Steel column response to thermal and long duration blast loads inside an air blast tunnel

All explosions emit both thermal and blast energy. In recent years there have been several accidental explosive events that have emitted high thermal loads with the potential to cause thermo-mechanical damage to structures. Attempts to experimentally simulate these thermal loads and observe the response of structures to combined thermal and blast loads have not proven successful. This paper focuses on the design of, and results from a series of experimental trials investigating the response of steel columns to combined thermal loads from ceramic heating elements and long-duration blast loads within an Air Blast Tunnel (ABT). The combined effect of compressive loads from heavy-duty springs is also shown. The trials concluded that the ceramic heating elements were suitable to heat steel columns to levels initiating thermo-mechanical damage. Results from the tests showed an increased structural response in the columns subject to high thermal, compressive and blast loads compared to the isolated blast load. Numerical modelling of the columns is detailed and compared to trial results, providing validation for the computational methods. The experimental trials set a benchmark for future trials and provided results to validate the synergistic response of steel structures to combined blast and thermal loads from explosive events.