1Associate Professor, Department of Mechanical Engineering, Ghousia college of Engineering, Ramanagaram, VTU, Belgaum, India
2Professor, Department of Mechanical Engineering, Ghousia college of Engineering, Ramanagaram, VTU, Belgaum, India
3PG student, Department of Mechanical Engineering, Ghousia college of Engineering, Ramanagaram, VTU, Belgaum, India
The present investigation was aimed at the study of influence of face sheet thickness on the flexural behaviour of thick face sheet sandwich beams. To pursue this, number of sandwich beam models of different face sheet thickness were generated and analyzed using validated FEM/ANSYS. Finite element models of sandwich beams were obtained successfully using nonlinear shell 91elment for face sheet(orthotropic material) and 8noded shell 98 element for core(isotropic material) of sandwich beam. The span length, width and the core thickness remain constant for all the sandwich beam models chosen for study. The work mainly focus on to predict the effect of face sheet thickness on the beam capacity (Ps). For each model of study, the safe beam capacity(Ps) was obtained using two criterions i.e. Maximum normal stress criterion(σmax) and Maximum shear stress criterion(τmax). From the present investigation it was observed that both the criterions give the same value of beam capacity for thin face sheet sandwich beams i.e. beams of (d/t)=10 to 12. As the thickness of face sheet increases i.e. beams of (d/t)<5 the beam capacity (Ps) reaches to asymptotic state as per maximum shear stress theory and the nearly hyperbolic in case of normal stress theory. From the study it is concluded that, for PUF cored sandwich beams, high thickness face sheets are unsuitable because for a weak core, face sheet become very strong element which is unrealistic combination of weak & strong elements. The area of investigation extended further to study the effect of face sheet thickness on performance parameters such as face sheet stress (σf), core shear(τ) & beam deflection (y) within elastic region for different face sheet thickness. From the study it was also observed that, thin face sheet beams are sensitive to load than that of thick face sheet beams, because as mid span load over the beam increases both stresses and deflection increases drastically. i.e. the slope of variation is higher as compared to that of thick face sheet beams. It is also observed that as thickness of the face sheet increases, i.e. beams of (d/t)<5 the beams become insensitive to initial load and asymptotes.
Face sheet thickness, Beam capacity, Core shear, FEM/ANSYS
