As it is well known, the behavior of FRP profiles is affected by deformability and buckling phenomena. The high ratio of the longitudinal elasticity modulus to the transverse one, the influence of the shear deformations and the usual slenderness ratios generally represent coupled terms affecting the structural performance. Many experimental and theoretical studies are available with regard to these topics. Within this context, the authors propose a new simplified approach to analyze the pre-buckling behavior of thin-walled composite beams which consists in removing the classical hypothesis of transversal rigidity. More in detail, the generic cross-section is represented by a defined number of thin-rectangles interconnected by non-linear rotational springs, thus allowing each thin component to exhibit a local torsional rotation although the axial and lateral displacement continuity is preserved. Timoshenko beam hypotheses are introduced with the aim of modeling the kinematics of each component while the springs above introduced are characterized by a bilinear relationship relating the torsional interaction per unit length to the torsional rotation discontinuities between two adjacent components. This model has the advantage of allowing more general constraints concerning the torsional degrees of freedom of each thin component. Numerical results obtained via a variational formulation by means of the finite element method are presented and discussed.
Buckling of composite thin walled beam - 17th International Conference on Composite Structures - University of Porto
MANCUSI, Geminiano
2013-01-01
Abstract
As it is well known, the behavior of FRP profiles is affected by deformability and buckling phenomena. The high ratio of the longitudinal elasticity modulus to the transverse one, the influence of the shear deformations and the usual slenderness ratios generally represent coupled terms affecting the structural performance. Many experimental and theoretical studies are available with regard to these topics. Within this context, the authors propose a new simplified approach to analyze the pre-buckling behavior of thin-walled composite beams which consists in removing the classical hypothesis of transversal rigidity. More in detail, the generic cross-section is represented by a defined number of thin-rectangles interconnected by non-linear rotational springs, thus allowing each thin component to exhibit a local torsional rotation although the axial and lateral displacement continuity is preserved. Timoshenko beam hypotheses are introduced with the aim of modeling the kinematics of each component while the springs above introduced are characterized by a bilinear relationship relating the torsional interaction per unit length to the torsional rotation discontinuities between two adjacent components. This model has the advantage of allowing more general constraints concerning the torsional degrees of freedom of each thin component. Numerical results obtained via a variational formulation by means of the finite element method are presented and discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
