In-plane shear behaviour of composite walling with profiled steel sheeting

This thesis introduces a novel form of double skin composite walling with profiled steel sheeting and an infill of concrete. This is a logical extension of research on composite slabs with profiled steel sheeting currently known as popular "Fastrack" construction. The composite walling is thought to be specially applicable as shear or core walls in steel frame buildings. The profiled steel sheeting will act as a temporary shear bracing to stabilise the frame against wind and destablising forces during construction and also act as a form work for infill of concrete. In the service stage, they will act as a reinforcement to carry axial, lateral and in-plane forces. This thesis investigates the behaviour of composite walls under in-plane shear so that they can be used as shear elements in buildings. The investigation includes analytical, numerical and small scale model tests. Design recommendations for the composite walls are the final aim of the research. The investigation is based on the concept that the in-plane shear strength and stiffness of the composite wall will be derived from the individual sheeting, concrete core and from the interaction between the two. Based on above, individual behaviour of the sheeting and concrete core was studied before considering the composite wall as a whole. A shear rig has been designed and fabricated to carry out the model tests of approximately 1/6 th scale using very thin sheeting (profiled in house) and microconcrete. Analytical equations for the shear strength and stiffness of the sheeting, profiled concrete and composite wall are derived. These equations are validated by model tests and finite element analysis. Finite element analysis included modelling of composite walling with full composite action and some parametric studies using interface elements. The stiffness of the composite wall is found to be greater than the individual summation of stiffness of the sheeting and concrete core. The profiled steel sheeting will provide sufficient shear bracing to the frame during construction. The composite wall is capable of taking high in-plane shear loads which is greater than the summation of individual capacity of the sheeting and concrete and confirms its potential to be used as shear elements in buildings. Simple equations for the calculation of shear strength and stiffness of the composite wall are derived which can safely be used for design purposes. Further research directions are also outlined.This thesis introduces a novel form of double skin composite walling with profiled steel sheeting and an infill of concrete. This is a logical extension of research on composite slabs with profiled steel sheeting currently known as popular "Fastrack" construction. The composite walling is thought to be specially applicable as shear or core walls in steel frame buildings. The profiled steel sheeting will act as a temporary shear bracing to stabilise the frame against wind and destablising forces during construction and also act as a form work for infill of concrete. In the service stage, they will act as a reinforcement to carry axial, lateral and in-plane forces. This thesis investigates the behaviour of composite walls under in-plane shear so that they can be used as shear elements in buildings. The investigation includes analytical, numerical and small scale model tests. Design recommendations for the composite walls are the final aim of the research. The investigation is based on the concept that the in-plane shear strength and stiffness of the composite wall will be derived from the individual sheeting, concrete core and from the interaction between the two. Based on above, individual behaviour of the sheeting and concrete core was studied before considering the composite wall as a whole. A shear rig has been designed and fabricated to carry out the model tests of approximately 1/6 th scale using very thin sheeting (profiled in house) and microconcrete. Analytical equations for the shear strength and stiffness of the sheeting, profiled concrete and composite wall are derived. These equations are validated by model tests and finite element analysis. Finite element analysis included modelling of composite walling with full composite action and some parametric studies using interface elements. The stiffness of the composite wall is found to be greater than the individual summation of stiffness of the sheeting and concrete core. The profiled steel sheeting will provide sufficient shear bracing to the frame during construction. The composite wall is capable of taking high in-plane shear loads which is greater than the summation of individual capacity of the sheeting and concrete and confirms its potential to be used as shear elements in buildings. Simple equations for the calculation of shear strength and stiffness of the composite wall are derived which can safely be used for design purposes. Further research directions are also outlined