Influenza del coefficiente di poisson sul comportamento in compressione di colonne composte acciaio-calcestruzzo a sezione circolare

In the paper an analytical model able to predict the whole compressive response of stub CFT subjected to uniaxial compression is presented and discussed. Cases examined re-ferred to member with circular cross-section having length 400 mm and diameter ranging be-tween 88.9 and 457 mm and wall thickness between 6 and 8 mm. Two steel grades of 275 and 460 MPa yielding stress were examined and four concrete grades were investigated (20, 28, 40 and 45 MPa). The proposed model take into account of the variable confined pressures exercised by steel wall on concrete core and of the biaxial state of stresses induced in steel wall. The model was verified both in term of load-shortening curves with data available in the literature and with most recent codes (Eurocode 4, 1995 and Japanese code AIJ ) in term of load carrying capa-city showing good agreement.