In this research we have prepared a composite material by using Vegetative Cellulose Fibers of Cannabis (Cann F) to reinforced a matrix of Unsaturated Polyester (UP) resin. This kind of fibers is distinguished by good properties such as high tensile strength, low elongation, thermal resistance and low cost. The impact strength was tested by using Charpy method for three materials (UP resin), composite (UP / Cann F) and composite (UP/Glass F). The results indicated that the fracture energy (Uc) decreased as the notch depth (a) increased on the sample from (0.7 mm) up to (4.9 mm). However, the fracture energy increased as the temperature of the composite increased for different temperatures of (0, 35, 50 and 75) oC. It was noticed that the Material toughness (Gc) has been improved significantly, where in case of the composite (UP /Cann F), the improvement of (Gc) was from (2.45 kJ/m2 ) to (14.5 kJ/m2 ) and it was (17 kJ/m2 ) for composite (UP/GF) has been measured at (35) oC. When those composite materials (UP/Cann F) exposed to humidity for a period of (72 hrs) without immersion, their properties did not change, hence the effects are not of chemical but of physical nature. The conclusion, the difference between the toughness of the material (Gc) for the reinforced composites by Cannabis and E-glass fibers for all temperatures is not large, so this encourage the development of Cannabis fiber reinforced composites in the future to abundance, and low cost for industrial investment
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 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 Cooper-Harper rating of aircraft handling qualities has been adopted as a standard for measuring the performance of aircraft. In the present work, the tail plane design for satisfying longitudinal handling qualities has been investigated with different tail design for two flight conditions based on the Shomber and Gertsen method. Tail plane design is considered as the tail/wing area ratio. Parameters most affecting on the aircraft stability derivative is the tail/wing area ratio. The longitudinal handling qualities criteria were introduced in the mathematical contributions of stability derivative. This design technique has been applied to the Paris Jet; MS 760 Morane-Sualnier aircraft. The results show that when the tail/wing area ratio increases the aircraft stability derivative increases, the damping ratio and the natural frequency increases and the aircraft stability is improved. Three regions of flight conditions had been presented which are satisfactory, acceptable and unacceptable. The optimum tail/wing area ratio satisfying the longitudinal handling qualities and stability is (0.025KeywordsLongitudinal Handling---Stability---Tail Design