DYNAMICAL RESPONSE OF COMPOSITE STEEL DECK FLOORS

Abstract

STRUCTURAL ENGINEERS ARE NOWADAYS FACING A SIGNIFICANT CHALLENGE RELATED TO THE DEVELOPMENT OF LIGHTER AND ECONOMICAL COMPOSITE STEEL-CONCRETE FLOOR STRUCTURES. A DIRECT CONSEQUENCE OF THIS NEW DESIGN TREND IS A CONSIDERABLE INCREASE IN THE PROBLEMS RELATED TO UNWANTED FLOOR VIBRATIONS. THIS PHENOMENON IS BECOMING VERY FREQUENT IN A WIDE RANGE OF STRUCTURES SUBJECTED TO RHYTHMIC DYNAMICAL ACTIONS. THE PROPER CONSIDERATION OF ALL THE ABOVE-MENTIONED ASPECTS POINTED OUT THE DEVELOPMENT OF A PROPERLY CALIBRATED FINITE ELEMENT MODEL THAT COULD ACCURATELY REPRESENT ITS STRUCTURAL RESPONSE. THE MODEL WAS USED TO INVESTIGATE A REAL COMPOSITE FLOOR DYNAMIC BEHAVIOUR BASED ON THE DETERMINATION OF ITS NATURAL FREQUENCIES AND VIBRATION MODES LATER TO BE COMPARED TO AVAILABLE EXPERIMENTAL EVIDENCE. THE INVESTIGATED COMPOSITE FLOOR HAS 18M X 31M AND IS USED FOR DANCING ACTIVITIES. PRELIMINARY RESULTS INDICATED THAT, FOR EVERY STUDIED COMPUTATIONAL MODEL, THE VALUES OF THE STRUCTURE NATURAL FREQUENCIES COULD BE SIGNI¯CANTLY AFFECTED. HOWEVER, THE VIBRATION MODES REMAINED VERY SIMILAR DESPITE OF THE ADOPTED COMPUTATIONAL MODEL.