• Steel and Composite Structures
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• v.6 no.5
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• pp.435-457
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• 2006

The paper presents the cost optimization of composite floor trusses composed from a reinforced concrete slab of constant depth and steel trusses consisting of hot rolled channel sections. The optimization was performed by the nonlinear programming approach, NLP. Accordingly, a NLP optimization model for composite floor trusses was developed. An accurate objective function of the manufacturing material, power and labour costs was proposed to be defined for the optimization. Alongside the costs, the objective function also considers the fabrication times, and the electrical power and material consumption. Composite trusses were optimized according to Eurocode 4 for the conditions of both the ultimate and the serviceability limit states. A numerical example of the optimization of the composite truss system presented at the end of the paper demonstrates the applicability of the proposed approach.

• Steel and Composite Structures
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• v.7 no.2
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• pp.105-118
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• 2007

On September $11^{th}$ 2001, the twin towers of the World Trade Center in New York City were struck by two hijacked airplanes. Despite severe local damage induced by the impact, the towers were able to sustain 102 and 56 minutes of the subsequent multi-storey fires before collapsing. The purpose of this study is to contribute to the understanding of the in-fire performance of composite trusses by examining the behaviour of the longer-span type used in the towers. It makes no attempt to be a forensic study of the actual events. Using the finite element package Vulcan, the structural mechanics of typical long-span composite floor trusses are explained, under a variety of scenarios, as the fire temperatures rise. Different boundary conditions, degrees of protection and loading are all covered, the results being presented mainly in the form of graphs of deflection and internal force of members against time.

• Journal of Korean Society of Steel Construction
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• v.21 no.6
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• pp.637-646
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• 2009

The composite actions of truss beams and floor slabs are not reflected on the design of the truss beam in domestic practice. In this research, basic experiments were conducted on a composite truss with the top and bottom chord members consisting of the H-shaped members. The tests were performed to evaluate the mechanical behaviors of the composite truss on the effects with the shear studs and without them. The specimens consisted of the steel truss and non-composite and composite trusses, and one-point-concentrated loading at the center and equivalent loading were monotonically applied. The composite effects were experimentally identified in the composite trusses using the shear stud connectors.