Analysis of an alternative topology for steel-concrete-steel sandwich beams incorporating inclined shear connectors

摘要

This thesis presents a new concept in steel-concrete-steel sandwich construction in whicha bi-directional corrugated-strip core is proposed as an alternative inclined shear connector.The focus is on the feasibility study of fabrication techniques and the theoreticalstudy of the structural responses of both unfilled and concrete-filled steel-concrete-steelsandwich beams under static flexural loading using numerical and analytical methods.Two possible fabrication techniques to create the proposed bi-directional corrugatedstripcore are presented. The unfilled sandwich beam is studied using a finite element method and three analytical methods referred to as the modified stiffness matrix, thebraced frame analogy, and the discrete beam methods The finite element method is used to investigate the stiffness and strength behaviour of the unfilled sandwich beam.The modified stiffness matrix method provides good correlation with the finite elementmethod. The other two analytical methods are less accurate. The assessment of the effectof geometrical parameters defining the bi-directional corrugated-strip core is carriedout. The responses of the strength and stiffness, especially the transverse shear stiffness,are examined and discussed. The optimum configuration of the core is found at the angleof the inclined part of the corrugation is about 45o. The concrete-filled sandwich beamis studied using the fnite element method. The finite element method is used to investigatethe transverse shear strength and the crack development of a four-point loadedconcrete-filled sandwich beam. The assessment of the effect of geometrical parametersdefining the inclined shear connectors is carried out. The responses of the concrete-filledsandwich beam are examined and discussed. The optimum advantage of the transverseshear strength of the concrete-filled sandwich beam is also found when the inclined shearconnectors align at an angle 45o. It is found that creating the proposed core with a 45opattern provides a great advantage in transverse shear stiffness and strength in both theunfilled and concrete-filled sandwich beams.