Plates with interior openings are often used in both modern and classical aerospace, mechanical and civil engineering. The understanding of the effects of two cutouts on the stress concentration factor, maximum stress and deflections in perforated clamped rectangular plates, were considered. Parameters such as location, size of cutout and the aspect ratio of plates are very important in designing of structures. These factors were presently studied and solved by finite element method (ANSYS) program. The results based on numerical solution were compared with the results obtained from different analytical solution methods. One of the main objectives of this study is to demonstrate the accuracy of the analytical solution for clamped square plate. In general, the results of the square clamped plates with two cutouts come out in good agreement. The results presented here indicated that the maximum stress, deflection of perforated plates can be significantly changed by using proper cutouts locations and/or size. The results show that the rectangular plate containing two cutouts arranged along the width is stronger and stiffer than when arranged along the length at a given spacing, and the square plate is always stronger and stiffer than an equivalent rectangular plate for the same loading condition.
The present research studies experimentally the effect of the ratio of the centurial hollow on the average of laminar convective heat transfer and the thermal gradation of the thermal boundary layer of three square flat plates. An experimental set-up was made for this purpose containing basically three uniformly Aluminum flat plates of a centurial hollow representing (0.25,0.5,0.75) of the entire surface area of each plate. Each of the three plates were heated by a constant heat flux for a rang of Rayleigh number of (5.62x105≤Ra≤1.67x106).The study showed that increasing the hollow ratio causes to increase the average of convective heat transfer by increasing the average Nusselt number, and the increasing average from a ratio to another decreases by the increases of the hollow ratio. The increasing between the two surfaces at (m=0.25&m=0.5) reached (39.6%) and for (m=0.5&m=0.75) was less than that and reached (29.2%).The increase average between the biggest and smallest hollow ratio was (78%).The study also showed that the maximum thermal gradation was on the out side edge of the plates and increases with the increase of Rayleigh number and the hollow ratio.
Composite laminate plates, fabricated by bonding fiber–reinforced layers, were dynamically analyzed under different combinations of number of layers, type of cutout, hole dimensions, angle of lamination and type of dynamic loading . This work was achieved by the well–known engineering software (ANSYS). The toughness of composite plates was evaluated in terms of the normal stress in the direction of loading at the periphery of the cutout. The toughness was found to increase by increasing the number of layers, by setting the lamination angle at around 40o,by selecting hole dimensions to width of plate ratio of around 0.4 and by employing square cutouts or avoiding triangular cutouts. Also, composite plates were found to be more strain-rate-sensitive in ramp loading, with least number of layers and with triangular type of cutout.
This research presents an experimental and theoretical investigation of the effect of cutouts on the stress and strain of composite laminate plates subjected to static loads. The experimental program covers measurement of the normal strain at the edges of circular and square holes with different number of layers and types of composite materials by using strain gages technique under constant tensile loads. A numerical investigation has been achieved by using the software package (ANSYS), involving static analysis of symmetric square plates with different types of cutouts. The numerical results include the parametric effects of lamination angle, hole dimensions, types of hole and the number of layers of a symmetric square plate. The experimental results show good agreement compared with numerical results. It is found that increasing the number of layers reduces the value of normal strain at the edges of circular and square holes of a symmetric plate and the maximum value of stress occurs at a lamination angle of (30o) and the maximum value of strain occurs at a lamination angle of (50o) for the symmetric square plates subjected to uni-axial applied load. The hole dimensions to width of plates ratio is found to increase the maximum value of stress and strain of a symmetric square plate subjected to uniaxial applied load. Moreover, the value of maximum stress increases with the order of type of circular, square, triangular and hexagonal cutout, whereas the value of maximum strain increases with the order of type of circular, square, hexagonal and triangular cutout.
Since FGM orthotropic structures have such striking qualities as high strength, exceptional stiffness, stiffness-to-weight ratio, reduced cost, and high strength-to-weight ratio, they are employed extensively in the mechanical, aerospace, and civil engineering sectors. Thick plates and shells have more noticeable shear deformation effects. Therefore, in recent years, there has been a lot of interest in the vibration and buckling investigation of FGMs orthotropic plates and shells. Moreover, researchers have developed a variety of approaches and procedures for the examination of orthotropic FGM plates and shells. The majority of the literature review in this publication is focused on orthotropic FGMs plate and shell buckling and linear and nonlinear free vibration. In engineering practices, it is customary to use material-oriented or orthotropic materials in several domains to optimize the structures and maximize material properties, which is especially crucial for FG constructions. Solutions for the orthotropic FGM structure are studied analytically and numerically with different plate and shell theories.
The aim of current work is to investigate the tensioned composite plates with two types of cutouts. Many industrial applications use composite matrix with reinforcement fiber to obtain better properties. The objective of this work is divided into two parts, first the experimental work covers the measuring of the normal strain (εx) at the edges of (circular & square) holes that are perpendicular to the direction of the applied loads with different number of layers and types of cutouts of composite materials by using strain gages technique under constant tensile loads to compare with the numerical results. The second part is numerical work, which involves studying the static analysis of symmetric square plates with different types of cutout (circular – square). In static analysis, the effect of the following design parameters on the maximum stress (σx), strain (εx) and deflection (Ux) is studied. This part of investigation was achieved by using the software finite element package (ANSYS 5.4).
In this paper, the effect of using the strengtheners on the stress and deflection under the effect of a certain weight falling on plates made of aluminum alloys (Al Mg3)has been studied. The study was carried on through two aspects; experimentally and theoretically; theoretically by using (F.E.M LS. DYNA) program. After comparing the theoretical aspect and experimental aspect, greatly- close results at point of contact were found out, as follows: When using one strengthener, the stresses reduce by (14 %) and the deflection by (70%) with comparison of without stiffener case .When using two strengtheners at the ends, stresses reduce (77%) and the deflection (65%) .When using two strengtheners 8 cm apart, stresses reduce (56 % ) and the deflection ( 18%) . When using two strengtheners 4 cm apart, stresses reduce (60 %) and the deflection (31%)
A finite element method for free vibration analysis of generally laminated composite plateswith central crack and clamped edges have been studied using ANSYS 5.4 program. The fiber-reinforced composite materials are ideal for structural applications where highstrength-to-weight and stiffness-to-weight ratios are required, where structures must safelywork during its service life. But damages initiate a breakdown period on the structures.Cracks are among the most encountered damage types in the structures. The non-dimensionalfundamental frequency of vibration decreases with presence of cracks because, therigidity of cracked plate decreases. The natural frequency of plates depends on size andshape of the cracks, the effect of number of layers is found to be insignificant beyond fourlayers and the change of fiber orientation increasing the fundamental frequency of vibration.The results obtained have been compared with the available published literature with goodagreement results
In this study an attempt is made to develop a method of analysis dealing with a multi-layer composite continuous beam , for linear material and shear connector behavior in which the slip (horizontal displacement) and uplift force (vertical displacement) are taken into consideration. The cross-sectional area for the beam consists of three layers varying in thickness and shear stiffness. The analysis is based on a approach presented by Roberts[1], basically for two layer simply supported beam, under uniform and point loads , which takes into consideration horizontal and vertical displacement in interfaces. The analysis led to a set of eight differential equations containing derivatives of the fourth and third order. A program based on the present analysis is built using finite difference method using boundary conditions. A comparison between the present analytical solution and previous studies shows close agreement. Continuous composite beams are very important element in construction of high rise buildings , multi-story frames and bridges, due to great advantages that can be obtained by using this sort of structural elements, such as reducing the beam moments, suitable reduction in deflections. The model deals with continuous beam consisting from three layers as a cross-sectional area with inter-layer slip. The cross-sectional area consist of composite material including intermediate layer from concrete and an upper and lower material with high strength in tension and compression ( i.e. steel plates or steel beams )
The nonlinear finite element analysis has become an important tool, for the structural design and assessment of prestressed reinforced concrete members. However, design and assessment of torsion are still done with simplified analytical or empirical design methods. This paper pre-sents results from a numerical analysis using the ANSYS finite element program to simulate a prestressed concrete beams subjected to static and cyclic torque. The eight- node brick ele-ments SOLID65 are used for the idealization of concrete while the reinforcements are idealized by using 3D spar element LINK8. The steel plates are idealized by using three dimensional solid elements SOLID45. The results showed that the general behavior of the finite element models represented by torque- twist angle relationships show good agreement with the experimental results from the Abdullah's beams.
The antenna is a Modified Broadband Butterfly Antenna (MBBA). The technical parameters of such systems are heavily influenced by the qualities of the antenna feed devices. The aperture theory of antennas uses the representation of the radiation field of the antenna as a superposition of the fields of elementary sources, characterized by their type and amplitude-phase spatial distribution. The radiation field of an antenna of finite dimensions is a superposition of inhomogeneous spherical waves emitted by the antenna elements. This paper is primarily the study process, Radiation models were calculated using the model of the cavity plates, Simple Green model, and the strict commercial Electromagnetic Simulator. The modified active rectangular patches with the Gann diode were combined into arrays of E and H plane. Calculated and measured results for these two active arrays the beam scanning, the possibilities have been demonstrated for both arrays. The results of an electrodynamics numerical simulation were obtained. Broadband and multiband radio systems have already found widespread practical applications by utilizing basic antenna parameters and characteristics.