Influence Of Cutouts Research Articles

Design and Analysis of Aircraft Wing Rib with Different Configuration for A380 model

The wing rib of an aircraft is a very critical part. It provides airfoil contour to the wing. Its principal role in wing structure is that to transfer load from skin to stringers or other parts of wing. Cut-outs in aircraft structural components such as wing spars and ribs are commonly encountered in practice. Cut-outs are often necessary for lightening holes, passages for wire bundles, hydraulic and fuel pipes, control linkages, accessibility for final assembly and maintenance inspections. The shape of the cutout is a important parameter where depends on the cutout shape the structural parameters may get varied. The main objective in here is to study about the influence of cutout in rib section with different cutout shapes. The Airbus A380 model is considered and the rib section for the model is modeled using Solidworksmodeling package and the model is analyzed for different cutout shapes. The model has the cutout shapes such as circle, ellipse and rectangle, where the circular hole is a most practiced method in recent models. The numerical analysis is carried out in ANSYS static structural analysis to find the structural parameters such as stress, strain, deformation and weight.

Buckling of launch-vehicle cylinders under axial compression: A comparison of experimental and numerical knockdown factors

Metallic grid stiffened cylinders are often used as tank and interstage structures in launch-vehicle systems. When subjected to axial compression, these thin-walled shells are prone to buckling. The corresponding critical buckling load heavily depends on deviations from the ideal shell shape.In general, these deviations are defined as geometric imperfections and they can significantly reduce the critical load. Considering the influence of geometric imperfections into the design process of thin-walled shells poses major challenges for structural design.This article presents an overview regarding the modelling, analysis and design of metallic grid stiffened launch-vehicle cylinders. In comparison to commonly studied unstiffened cylinders, complex shells applied in aerospace engineering can have a completely different structural response to axial compression than their unstiffened counterparts. Advanced shell buckling design conceps like perturbation approaches and energy barrier criteria are applied and validated with experimental data. Finite element models are presented and described in detail. Important aspects like skin and weld buckling as well as the influence of cutouts are analyzed and discussed.

A higher order coupled frequency characteristics study of smart magneto-electro-elastic composite plates with cut-outs using finite element methods

This article deals with investigating the effect of cut-outs on the natural frequencies of magneto-electro-elastic (MEE) plates incorporating finite element methods based on higher order shear deformation theory (HSDT). In order to consider the influence of cut-out, the energy of the cut-out domain is subtracted from the total energy of the entire plate. The governing equations of motions are derived through incorporating Hamilton’s principle and the solution is obtained using condensation technique. The proposed numerical formulation is verified with the results of previously published literature as well as the numerical software. In addition, this research focuses on evaluating the effect of geometrical skewness and boundary conditions on the frequency response. The influence of cut-outs on the degree of coupling between magnetic, electric and elastic fields is also investigated.

Vibration and buckling analyses of FGM plates with multiple internal defects using XIGA-PHT and FCM under thermal and mechanical loads

In this paper, the vibration and buckling analyses of the FGM (functionally graded material) plates with multiple internal cracks and cutouts under thermal and mechanical loads are numerically investigated using the combined XIGA-PHT (extended isogeometric analysis based on PHT-splines) and FCM (finite cell method). Material properties are graded only in the thickness direction. The effective material properties are estimated by using either the rule of mixture or the Mori-Tanaka homogenization technique. The plate displacement field is based on the HSDT (higher-order shear deformation plate theory) without any requirement of the SCF (shear correction factor). The HSDT model can exactly represent the shear stress distribution and improve the accuracy of solutions. The PHT-splines can naturally fulfill the C1-continuous requirement of the HSDT model. The representation of internal defects is mesh-independent. The discontinuous and singular phenomena induced by the cracks are captured using the enrichment pattern in the XIGA, and the influence of cutouts is implemented by the FCM. The geometries of cutouts are captured by means of adaptive quadrature procedure based on a simple unfitted structural mesh, which avoids the need for multiple patches to describe the complex geometry and eliminates the enforcement of C1-continuity patch-coupling across the patch boundaries. The initial mesh density around the cracks and cutouts can be controlled flexibly utilizing the local refinement property of the PHT-splines. After validating the results of the developed approach with those available in the literature, the effects of material gradient index, side to thickness ratio, boundary conditions, cutout size and crack length on the normalized frequency and the critical buckling parameter are investigated. Numerical results illustrate the effectiveness and accuracy of the present approach.

Влияние вырезов на прочность цилиндрических отсеков ракет-носителей при неупругом деформировании материала

Влияние вырезов на прочность цилиндрических отсеков ракет-носителей при неупругом деформировании материала