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07.18: Cold‐formed C‐sections encased in ultra‐lightweight concrete: Development of a Eurocode‐based design method
Author(s) -
Hegyi Péter,
Dunai László
Publication year - 2017
Publication title -
ce/papers
Language(s) - English
Resource type - Journals
ISSN - 2509-7075
DOI - 10.1002/cepa.208
Subject(s) - bracing , buckling , structural engineering , eurocode , stiffness , beam (structure) , foundation (evidence) , infill , cold formed steel , materials science , engineering , archaeology , brace , history
ABSTRACT A new direction of development in the field of light‐gauge building systems is when the load bearing elements made of cold‐formed steel (CFS) sections are encased in an ultra‐lightweight material. This material, apart from heat insulation and fire protection effects, can provide bracing effect to the CFS elements, too, therefore can increase the resistance against stability failures. Such lightweight material is the polystyrene aggregate concrete (PAC). Based on previous experimental results this paper develops design method for calculating local, distortional and global resistance of PAC‐encased CFS C‐sections. The proposed design method is based on the specifications of Eurocode, therefore applies the effective width method for calculating local buckling. The proposed procedure considers the effect of continuous bracing of PAC by replacing it with an elastic half‐space, similar to sandwich beam theory. Close form equations are derived to be able to calculate the effective width of plate elements by hand calculation. Distortional buckling is treated as buckling of an equivalent beam resting on elastic foundation, considering the additional stiffness provided by the infill material. The global flexural buckling failure modes of columns are dealt with separately using different mechanical models. Each calculation procedure was compared to existing experimental results in order to evaluate them.