Brandpåverkan och dimensionering av bärande delar

The purpose of this bachelor thesis is to describe how structural design for fire is done. The aim is to produce a report that step by step describes how the design is performed. Structural design for steel and glulam beams with and without fire protection are performed to see what the differences are when fire protection is used and when it’s not. The glulam beams are also inspected in the computer software SPFiT 2.0, to see how efficient such software is. For glulam beams, the differences between structures with and without fire protection depend on how long the fire lasts. In protected structures, no carbonization occurs at the beginning, while carbonization starts directly for unprotected. If the design is exposed to fire for a long time, the differences are not so great. For steel beams, the differences between protected and unprotected constructions are clearer. The steel temperature determines the load capacity and if the structure is not protected the temperature will rise very fast. However if the design is protected the steel temperature can be kept lower much longer. SPFiT 2.0 turns out to be very effective as it saves a lot of time when performing structural design for fire. The results from SPFiT 2.0 correspond with the results from hand calculations. The report is structured in four parts. The first part is generally about how fire occurs and how it is spread. It also includes various laws and regulations that are important for designers to follow. The second part deals with wood in structural parts and investigates what happens to the material when it is exposed to fire and what protection methods are available. Here the design process for wood constructions is described step by step. The third part is about steel in structural parts and investigates what happens to the material when it is exposed to fire and what protection methods are available. Here the design process for steel constructions is described step by step. In the fourth part of the report, the results from calculations of glulam beams in three different cases are compared with the results from the software SPFiT 2.0