This work is concerned with the vibration attenuation of a smart beam interacting with fluid using proportional-derivative PD control and adaptive approximation compensator AAC. The role of the AAC is to improve the PD performance by compensating for unmodelled dynamics using the concept of function approximation technique FAT. The key idea is to represent the unknown parameters using the weighting coefficient and basis function matrices/vectors. The weighting coefficient vector is updated using Lyapunov theory. This controller is applied to a flexible beam provided with surface bonded piezo-patches while the vibrating beam system is submerged in a fluid. Two main effects are considered: 1) axial stretching of the vibrating beam that leads to the appearance of cubic stiffness term in beam modelling, and 2) fluid effect. Fluid forces are decomposed into two components: hydrodynamic forces due to the beam oscillations and external (disturbance) hydrodynamic loads independent of beam oscillations. Simulation experiments are implemented using MATLAB/SIMULINK to verify the correctness of the proposed controller. Two piezo-patches are bonded on the beam while an impulse force with multi-pulse is applied to excite the beam vibration. The results show the strength of the proposed control structure.
Charge multipole Coulomb scattering form factors in 48Ca nucleus have been reproduced utilizing the theory of nuclear shell. The efficient two-body nuclear potential fpbm is considered to construct the-spin orbit term LS vectors with Harmonic Oscillator HO potential as a wave function of single particle in Fp shell. Discarded spaces ( core + higher configuration) are taken into account through the Core polarization effect by model space with accurate two-body potential of Gogny to interact the LS operating particles with the discarded space pair ( particle-hole) with energy of excitation equal to 2ћω. Gogny interaction has been selected as it had succeeded in nuclear shell theory. The computed results were compared with th
... Show MoreBased on analyzing the properties of Bernstein polynomials, the extended orthonormal Bernstein polynomials, defined on the interval [0, 1] for n=7 is achieved. Another method for computing operational matrices of derivative and integration D_b and R_(n+1)^B respectively is presented. Also the result of the proposed method is compared with true answers to show the convergence and advantages of the new method.
In this paper, the static analysis for finding the best location of boxes inside the composite wing-box structure has been performed. A software ANSYS (ver.11) was used to analyses the Aluminum wing to find the maximum stresses reached in. These results are used as a base for the composite wingbox to find the numbers of layers and location of the box beam and its dimensions so that the composite wingbox may carry the same loading conditions in the Aluminum wing. Analysis showed that a composite wingbox having two boxes is better than the single or triple boxes wing based on stress to weight ratio. Mass saving of (40%) had been achieved when composite wing-box is used instead of Aluminum wing.
Urban morphological approach (concepts and practices) plays a significant role in forming our cities not only in terms of theoretical perspective but also in how to practice and experience the urban form structures over time. Urban morphology has been focused on studying the processes of formation and transformation of urban form based on its historical development. The main purpose of this study is to explore and describe the existing literature of this approach and thus aiming to summarize the most important studies that put into understanding the city form. In this regard, there were three schools of urban morphological studies, namely: the British, the Italian, and the French School. A reflective comparison between t
... Show MoreIn this paper, we provide some types of - -spaces, namely, - ( )- (respectively, - ( )- , - ( )- and - ( )-) spaces for minimal structure spaces which are denoted by ( -spaces). Some properties and examples are given.
The relationships between a number of types of - -spaces and the other existing types of weaker and stronger forms of -spaces are investigated. Finally, new types of open (respectively, closed) functions of -spaces are introduced and some of their properties are studied.
The structure is considered in its scientific formula one of the concepts which complete the architectural image that seeks to take out an effective and attractive structure in contemporary architectural production, especially that the structure -in general- represents strength in addition to delight and functional benefits according to Vitruvius trinity. So, the role of structure depends on making its aesthetical properties able to give efficiency within architectural product. That has come through adoption of intellectual mechanism of structural means and details –as a whole or parts- and focused on structure with the recipient's needs, aesthetical, and sensory purposes in addition to its fundamental role of stabilit
... Show MoreThis research concerns with the study of the sand dunes sedimentary structures in two areas from dunes field of Najaf governorate these are; 1)Al-Rahimiya and 2)Ain Mazlun areas, where the first area consists from barchans, barchanoid, and nabkha dunes types, while the second area has the dome, longitudinal, nabkha, and sand sheet dunes types.
The affected prevailing wind direction is obvious on the study area, where has the NW-SE bearing and the sedimentary structures were influenced by prevailing and local wind directions in studied areas.
Many types of sedimentary structures recognized in the studied areas these are; cross stratification, ripple marks, slump (grain flow), adhesion structures, and bioturbation structure
... Show MoreEmploying the social personalities (celebrities) in all fields (artistic, sports, media, etc.) is an important media and visual communication means of identification for the companies and institutions in order to convey the advertising idea in accordance with the creative, aesthetic and functional principles aimed at promoting products and gaining the symbolic value for the company. This study investigates the employment of social personalities in the commercial advertising design in order to pinpoint the importance of employing celebrities and their representation in the advertisement to convey the meaning that signifies the advertisement goal. Thus the question of the study is: "What are the mechanisms of employing celebrities in the d
... Show MoreReinforcing asphalt concrete with polyester fibers considered as an active remedy to alleviate the harmful impact of fatigue deterioration. This study covers the investigation of utilizing two shapes of fibers size, 6.35 mm by 3.00 mm and 12.70 mm by 3.00 mm with mutual concentrations equal to 0.25 %, 0.50 % and 0.75 % by weight of mixture. Composition of asphalt mixture consists of different optimum (40-50) asphalt cement content, 12.50 mm nominal aggregate maximum size with limestone dust as a filler. Following the traditional asphalt cement and aggregate tests, three essential test were carried out on mixtures, namely: Marshall test (105 cylindrical specimens), indirect tensile strength test (21 cylindrical specimens)
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