The paper proposes a simple structural model for accurately describing the main characteristics of the non-linear postbuckling response of metallic stiffened plate girders subject to in plane bending and shear. To account for the possible formation at different stages of the load process of plastic hinges along the axes of flanges and stiffeners, both transversal and longitudinal, these elements are modelled as linear elastic-perfectly-plastic beams. Web panels are instead considered as ideal elastic membranes, therefore unable of sustaining any compressive stress. The relevant stiffness of the girder substantiates the use of a first-order theory for deducing its postcritical response. Equilibrium is achieved by recourse to the virtual work principle. Use of a relaxed strain energy for the web permits of accurately determining the tension field arising within each buckled panel. The sequence of the postcritical equilibrium states corresponding to increasing load values is numerically derived by means of a standard FEM iterative procedure. Comparing the numerical results with the experimental responses of typical steel plate-girders, well documented in literature, finally performs model validation.
The Postbuckling Behaviour of Metallic Stiffened Plate Girders
BARSOTTI, RICCARDO;LIGARO', SALVATORE SERGIO
2001-01-01
Abstract
The paper proposes a simple structural model for accurately describing the main characteristics of the non-linear postbuckling response of metallic stiffened plate girders subject to in plane bending and shear. To account for the possible formation at different stages of the load process of plastic hinges along the axes of flanges and stiffeners, both transversal and longitudinal, these elements are modelled as linear elastic-perfectly-plastic beams. Web panels are instead considered as ideal elastic membranes, therefore unable of sustaining any compressive stress. The relevant stiffness of the girder substantiates the use of a first-order theory for deducing its postcritical response. Equilibrium is achieved by recourse to the virtual work principle. Use of a relaxed strain energy for the web permits of accurately determining the tension field arising within each buckled panel. The sequence of the postcritical equilibrium states corresponding to increasing load values is numerically derived by means of a standard FEM iterative procedure. Comparing the numerical results with the experimental responses of typical steel plate-girders, well documented in literature, finally performs model validation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
