S.K. Malhotra

Vibration and damping analysis of orthotropic triangular plates

Abstract The effect of fibre orientation and boundary conditions on the vibration and damping behaviour of thin orthotropic triangular plates is studied by using a three-noded triangular plate finite element. Isosceles triangular plates having three different included angles are analyzed.

Some studies on buckling of laminated composite thin walled box beams

Buckling of laminated composite thin walled rectangular box beam configurations has been studied. The increasing use of composite materials in the construction of aeronautical and civil engineering structures has generated a special interest in the analysis of elastic stability of laminated composite structure subjected to inplane loadings. The effect of number of layers, lay-up sequence and fibre angle on the buckling load is studied for symmetric and anti-symmetric lay-ups.

Vibrations of orthotropic triangular plates

Abstract The effect of fibre orientation and boundary conditions on vibration behaviour of thin orthotropic triangular plates is studied using a three-noded triangular plate finite element. Isosceles triangular plates having three different included angles are analysed.

Effect of fibre orientation and boundary conditions on the vibration behaviour of orthotropic rhombic plates

Abstract The effect of fibre orientation on the frequencies of thin, rhombic, orthotropic plates has been studied using a parallelogrammic, orthotropic plate finite element for various boundary conditions and skew angles. The results indicate that, for a given skew angle and boundary conditions, the fibre orientation of such plates can be chosen to achieve the desired natural frequency.

Effect of fibre orientation and boundary conditions on the vibration behaviour of orthotropic square plates

Abstract The effect of fibre orientation on the frequencies of thin square orthotropic plates is studied using a rectangular orthotropic plate finite element for various boundary conditions. The main purpose of the study is to find out in what way boundary conditions influence the frequencies of orthotropic square plates.

Some studies on static analysis of composite thin-walled box beam

Abstract Long hollow rectangular composite box beam configurations are used quite commonly in engineering structures especially in aerospace, ship building and civil engineering construction. In the present study a finite element method is presented for the determination of transverse displacement and layer-wise stress distribution of thin-walled plate structure assembled from flat plates. The finite element formulation is based on Mindlin plate theory which takes shear deformation of the beam into consideration. Effect of material and lay-up sequence on the structural behavior of rectangular cross-section thin-walled composite box beam under uniformly distributed load on the top face with end supports is studied.

Strength Prediction in Multi-pin Joints from Equivalent Material Properties in Composite Laminates.

The present work aims to predict failure in composite laminate joints from equivalent material properties. Three- and four-pin joints made of glass fiber/epoxy with [45°/− 45/°]s and [0°/90°/°l]s lay up are considered. A 3D finite element analysis is performed to study the propagation of damage and to predict failure load. Progressive damage analysis is carried out using von-Mises stress as the failure when the stress exceeds the laminate strength. Failure in three- and four-pin joints by equivalent material properties predicted the strength of the joint close to the experimental values with a degradation factor of 0.12.

Vibrations of stepped orthotropic square plates

Abstract The effect of fibre orientation and boundary conditions on the vibration behaviour of stepped orthotropic square plates is studied using the Finite Element Method. The results are compared with those of constant thickness plates.

Vibrations of orthotropic square plates having variable thickness (linear variation)

Abstract The effect of fibre orientation on the natural frequencies of thin square orthotropic plates having variable thickness is studied using the Rayleigh-Ritz method for various boundary conditions. In the present study plates having linear variation in thickness in one direction (either X or Y) are studied.

A study on GRP skin/foam core sandwich structures

Abstract This paper presents a simple graphical procedure which allows a structural sandwich beam or panel to be designed from grp skin and foam core materials, so that the weight of the sandwich is a minimum. The method is based upon the well-known equations for bending rigidity, bending moment and weight of a sandwich beam.