ABSTRACT
A Area of steel section Ae Area of concrete Aev Area of concrete shear surface per unit length of
beam Asv Area of transverse reinforcement per unit length
of beam be Effective breadth of concrete flange, one side of
steel beam br Breadth of concrete rib B Breadth Be Total effective breadth of concrete flange d Depth of web D Depth of steel section Dp Overall depth of profiled steel sheet Ds Overall depth of slab Ee Modulus of elasticity of concrete Es Modulus of elasticity of steel f Natural frequency feu Characteristic cube strength of concrete (N mm -2) isk Characteristic strength of reinforcement Fv Average shear force h Overall height of stud connector he Depth of centroid of steel in compression k Reduction factor depending on profile shape K Degree of shear connection L Length of span Le Length between haunches Lo Distance between points of contraflexure M Moment Me Moment capacity of composite section Mev Reduced moment capacity
Mr Plastic moment capacity after deduction of web Mhe Limiting moment resistance for beam to column
connection Mp Plastic moment of resistance N Number of shear connectors in a group Na Actual number of shear connectors between
intermediate point and adjacent support Nn Number of shear connectors for negative moments Np Number of shear connectors for positive moments PI Proportion to total load which is long term Py Design strength of structural steel (N mm -2) Pv Shear capacity of a section Qn Capacity of shear connector in negative moment
regions Qp Capacity of shear connector in positive moment
regions Rc Resistance of concrete flange Rr Resistance of steel flange Rr Resistance of reinforcement Rs Resistance of steel beam Rw Resistance of overall web depth S Plastic modulus t Web thickness T Flange thickness Vr Shear resistance of concrete flange per unit length Wr Uniformly distributed design load xp Depth of plastic neutral axis
a e Modular ratio al Modular ratio for long term loading as Modular ratio for short term loading b Deflection be Deflection of composite beam
422 A.M. Price and D. Anderson
Deflection of steel beam Ratio of negative to positive plastic moments of resistance
1. INTRODUCTION
The term composite beam is generally applied to beams having a steel-concrete section, in which the two materials combine to act in such a way that the behaviour of the individual elements is modified. This action is possible because of inter-connection of the materials, either continuously, or at discrete points, along the length of the beam. Some examples of composite sections are shown in Fig. 1.
