EFFECT OF STATIC AND HARMONIC LOADING ON THE HONEYCOMB SANDWICH BEAM BY USING FINITE ELEMENT METHOD

The aim of this paper is to present a proposed honeycomb core shape and compare it with a normal hexagonal shape core in a sandwich beam. The sandwich cores are simulated in finite element with different materials; aluminum and epoxy-carbon with six layers are used as face sheet and the results are compared to those obtained theoretically. Simulation of 3-point bending test is performed in commercial software ANSYS to verify the analytical results with the numerical ones. Hence, for simplicity one layer of the skin is used on the equivalent model of sandwich for lesser computational time and more accurate evaluation. Simulation of harmonic analysis of hexagonal core and proposed core shape is carried out in frequency domain to identify the core with less deformation under high frequency and it can withstand harmful effects. The proposed core shape model having the same cell numbers and material as the normal hexagonal model is compared with experimental results; it is observed that the proposed core shape model has good flexural stiffness, resonance, fatigue, and stress resistance at a higher frequency

FREE VIBRATION INVESTIGATION ON RVE OF PROPOSED HONEYCOMB SANDWICH BEAM AND MATERIAL SELECTION OPTIMIZATION

In this paper, free vibration, modal and stress state analyses of honeycomb sandwich structures with different boundary conditions was investigated and major factors affecting the sandwich frequencies and stiffness due to material or parameter changes were determined. The representative volume element (RVE) method used in this work were analytically and numerically validated by comparing the obtained results to those available in literature. Firstly, unit cell method was used to capture the entire effects of different parameters on the free vibration of honeycomb sandwich structure in ANSYS. This study analyzed the natural frequencies of honeycomb sandwich structures with different core materials combination. The effects of foil thickness, boundary conditions, materials selection, density and presence of crack on sandwich structure were taken into consideration and examined. The proposed core had an inbuilt shaped reinforcement with different materials for effective resonance, fatigue and deformation resistance at much higher frequency

Nonlinear and Linearized Analysis of Vibrations of Loaded Anisotropic Beam/Plate/Shell Structures

L'abstract è presente nell'allegato / the abstract is in the attachmen

Analytical techniques and instrumentation, a compilation

Procedures for conducting materials tests and structural analyses of aerospace components are presented as a part of the NASA technology utilization program. Some of the subjects discussed are as follows: (1) failures in cryogenic tank insulation, (2) friction characteristics of graphite and graphite-metal combinations, (3) evaluation of polymeric products in thermal-vacuum environment, (4) erosion of metals by multiple impacts with water, (5) mass loading effects on vibrated ring and shell structures, (6) nonlinear damping in structures, and (7) method for estimating reliability of randomly excited structures

Experimental and Numerical Investigation of Static and Dynamic Analysis of Delaminated Composite Plate

Laminated composites are extensively used in various engineering industries like aerospace, civil, marine, automotive and other high performance structures due to their high stiffness to weight and strength to weight ratios, excellent fatigue resistance, long durability and many other superior properties compared to the conventional materials. Delamination is an insidious kind of failure, without being distinct on the surface which causes the layers of a laminated composite plate to detach. It is well known that the propagation of delamination is not only serious but also major concern for the designers in connection to the structural safety. Hence the presence of such defect has to be detected in time to plan the remedial action well in advance. The study aims to analyse mathematically the static, free vibration and transient behaviour of laminated structure with and without delamination by developing numerical models in MATLAB environment based on the higher order shear deformation theory in conjunction with finite element method. Also, a simulation model was developed using finite element software, ANSYS 15.0 and was used for analysis purpose. The static and dynamic analysis of laminated and delaminated plates has also been extended for an experimental validation. Three point bend test via UTM INSTRON 5967 and Modal test via PXIe-1071 was carried out on laminated and delaminated composite specimens and their responses were validated with those of numerical models and simulation model. Based on different numerical illustrations, the effectiveness and the applicability of the presently developed higher order models has been emphasised

Stability Analysis of Plates and Shells

This special publication contains the papers presented at the special sessions honoring Dr. Manuel Stein during the 38th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference held in Kissimmee, Florida, Apdl 7-10, 1997. This volume, and the SDM special sessions, are dedicated to the memory of Dr. Manuel Stein, a major pioneer in structural mechanics, plate and shell buckling, and composite structures. Many of the papers presented are the work of Manny's colleagues and co-workers and are a result, directly or indirectly, of his influence. Dr. Stein earned his Ph.D. in Engineering Mechanics from Virginia Polytechnic Institute and State University in 1958. He worked in the Structural Mechanics Branch at the NASA Langley Research Center from 1943 until 1989. Following his retirement, Dr. Stein continued his involvement with NASA as a Distinguished Research Associate

Who needs refined structural theories?

This paper discusses the question posed in the title and available options for the structural analysis of metallic and composite structures concerning the choice of 1D, 2D, and 3D theories. The focus is on the proper modeling of various types of mechanical behaviors and the associated solution’s efficiency. The necessity and convenience of developing higher‐order structural theories are discussed as compared to 3D models. Multiple problems are considered, including linear and nonlinear analyses and static and dynamic settings. Some possible guidelines on the proper selection of a model are outlined, and quantitative estimations on the accuracy are provided. It is demonstrated that the possibility of incorporating higher‐order effects in 1D and 2D models continues to remain attractive in many structural engineering problems to alleviate the computational burdens of 3D analyses