A weak shear web model for deflection analysis of deep composite box-type beams. (15th January 2018)

• Record Type: Journal Article
• Authors: Atashipour, S.R.; Girhammar, U.A.; Challamel, N.
• Is Part Of: Engineering structures. Volume 155(2018)
• Page Start: 36
• Page End: 49
• Publication Date: 2018-01-15
• Subjects: Box-type beams -- Weak shear web -- Shear deformations -- Sandwich-type of behaviour -- Partial-type of composite interaction; 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.2017.10.073
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: An accurate model for deflection of deep box-type composite beams is presented. Additional shear deformations in the sheathings between the frames are modelled. Deep box-beam deflection is shown to be as summation of three different effects. Abstract: Deep box-type beams, consisting of framing members and sheathings, are sensitive to shear deformations and hence appropriate refined theories or complicated magnification factors are needed to be used to obtain accurate results. For sheathings or webs between the framing members that are weak in shear, additional shear deformations occur corresponding to the relative axial displacement between the framing members. These sandwich-type or partial interaction-type of in-plane shear behaviour between the framing members, needs to be taken into account, especially when the web shear stiffness is very low. The composite box-type beam treated here is composed of three framing members with sheathings on both sides. To incorporate effects of the sheathings shear deformations between the framing members on the deflection, the sheathings, here called web interlayers, are modelled as shear media with equivalent slip moduli corresponding to a partially interacting composite beam model. Governing equilibrium equations of the model are obtained using the minimum total potential energy principle and solved explicitly. The obtained results are compared with those based on different conventional beam theories and 3-D finite element (FE) simulations. It is shown that the model is capable of predicting accurately the deflection for a wide range of geometry and property parameters. It is demonstrated that the deflection of such deep box-type beams can be expressed as the summation of three different effects, namely bending deformations, conventional shear deformations in the framing members and sheathings, and additional in-plane shear deformations or shear slips of the weak web causing relative axial displacements between the framing members.