Modeling floor systems for collapse analysis. (15th November 2016)

• Record Type: Journal Article
• Authors: Wan, Chen; Audi, Charlie; Sasani, Mehrdad
• Is Part Of: Engineering structures. Volume 127(2016:Nov. 15)
• Page Start: 278
• Page End: 286
• Publication Date: 2016-11-15
• Subjects: Modeling techniques -- Collapse resistance -- Floor system -- Compressive membrane action -- Energy balance; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2016.08.048
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Modeling slab and beam elevation difference significantly affects building response. For M −, modeling slab elevation more effectively constrains beam tendency to grow. This leads to higher axial compressive force and in turn moment capacity in beams. Compressive force in beams is limited by tensile (reinforcement) strength of slab. Additional moment developed by eccentricity of slab vs beam enhances beam strength. Abstract: Gravity load redistribution and collapse resistance of structures following loss of load bearing elements due to natural and manmade hazards significantly depend on the floor response. Effects of floor system modeling on collapse resistance of damaged structures are studied in this paper. In particular, axial and flexural constraints imposed by the floor slab on joists and beams of RC structures is evaluated and characterized. The axial constraint imposed by the slab leads to additional compressive force, enhancing flexural response and in turn load carrying capacity of beams and joists. The flexural constraint can be captured by proper modeling approaches and can help improve the response of floor joists and beams. It is shown that the method by which the floor system is modeled has considerable effects on the floor response following loss of load bearing elements. The effects of modeling techniques on the structural response are also evaluated from an energy point of view. The effects of flexural-axial, as well as torsional cracking of the floor slab are evaluated and characterized.