CYCLIC LOADING OF STEEL BEAM-COLUMN JOINT STRENGTHENED BY GFRP

Abstract

Steel beam-column joints are very important parts of every steel structures and have great influence on the stiffness and stability of the whole structure especially in seismic zones. To investigate the cyclic behaviour of beam-column joints, bolted end-plate connection are used due to good structural performance. The cyclic behaviour of beam-column joints can be conveniently represented by its flexural behaviour which is primarily shown by the moment –rotation (M-ϴ) relationship, this behaviour is non-linear even at low load levels. In fact, moment-rotation curves represent the result of a very complex inter action among the elementary parts constituting the connection. Recent codes have opened the door to the advanced methods for structural analysis which account for geometrical and material non-linearity’s, therefore advanced analysis methods require an accurate modelling of members and connections up to failure. The objective of this research is to study the effect of using glass fibre reinforced polymer (GFRP) sheets as a strengthening on the cyclic behaviour of beam column joints, GFRP sheets was used due to its economy. Twenty four models of strengthening beam-column joints were used to select the best location and thickness of GFRP sheets and study the effect of each strengthening on the ductility and rotation capacity of the joints. The analytical investigation utilizes nonlinear finite element modelling techniques using ANSYS program, considering both geometric and material nonlinearity. The results show that the strengthening of beam-column joint using GFRP sheets is very effective on improvement the cyclic behaviour of beam column joint.

Keywords Steel beam-column joint, Seismic zones, cyclic loading, GFRP sheets

SUPERVISORS Prof. Dr. Mohamed Mohamed Hussein Attabi Prof. Dr. Mohamed Saafan Abd-Elgawad