An experimental program was conducted to determine the residual of composite Steel Beams-Reinforced Concrete (SB-RC) deck floors fabricated from a rolled steel beam topped with a reinforced concrete slab, exposed to high temperatures (fire flame) of 300, 500, and 700ºC for 1 hour, and then allowed to cool down by leaving them in the lab condition to return to the ambient temperature. The burning results showed that, by exposing them to a fire flame of up to 300ºC, no serious permanent deflection occurred. It was also noticed that the specimen recovered 93% of 19.2 mm of the deflection caused by burning. The recovered deflection of burned composite SB-RC deck floor at 500ºC was 40% of 77.9 mm of the deflection caused by burning with a residual deflection of 46.4 mm. The greatest deterioration occurred when exposed to 700ºC, at this temperature, a higher unrecoverable permanent deflection was recorded (160.3 mm) of the maximum measured burning deflection (173.8mm), indicating that the percent recovered deflection was 8%. Then, all composite SB-RC deck floors were loaded until failure to determine the percent decrease in their ultimate capacity. The results were compared with the behavior of composite SB-RC deck floor without burning (reference specimen).
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.
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This study deals with the estimation of critical load of unidirectional polymer matrix composite plates by using experimental and finite element techniques at different fiber angles and fiber volume fraction of the composite plate.
Buckling analysis illustrated that the critical load decreases in nonlinear relationship with the increase of the fiber angle and that it increases with the increase of the fiber volume fraction.
The results show that the maximum value of the critical load is (629.54 N/m) at (q = 0°) and (Vf = 40 %) for the finite element method, while the minimum val
... Show MoreThe use of composite materials has vastly increased in recent years. Great interest is therefore developed in the damage detection of composites using non- destructive test methods. Several approaches have been applied to obtain information about the existence and location of the faults. This paper used the vibration response of a composite plate to detect and localize delamination defect based on the modal analysis. Experiments are conducted to validate the developed model. A two-dimensional finite element model for multi-layered composites with internal delamination is established. FEM program are built for plates under different boundary conditions. Natural frequencies and modal displacements of the intact and damaged
... Show MoreSince the invention of the automobile, no aspect of American life, including crime and its control, has remained untouched by this far-reaching innovation in transportation. Vehicular "hot pursuit"-when suspects in motor vehicles use excessive speed in attempting to elude the police. Unfortunately, accounts of wild chases across crowded inner city streets, through tree-lined suburban boulevards, and over remote country roads are very real and not merely fictional material created for entertaining television and motion picture audiences. The specter of "hot pursuit," complete with screaming sirens and red or blue flashing lights, has become a recurring fact of modem life.1 So, too, are the mishaps involving police vehicles or the vehicles pu
... Show MoreBackground: With the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.The present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (Hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). Materials and Methods: The samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). They were divided as the following: group I (control): the porcelain surface left u
... Show MoreThis research aimd to analyze the role of strategic entreprenenial on according to the external performance of a sample of Iraqi private banks, namely, (National Islamic Bank, Iraqi Ahli Bank, Baghdad Bank , Middle East Iraqi Investment Bank) has launched research in fundamental problem stems from the question seeking his response to the characterization of the problem which is improve banking performance through strategic entreprenenial and to achieve the goal of the research was to prepare a questionnaire included a number of questions about the independent research and approved variables accounting for the independent variable strategic entreprenenial and included four dimensions (entreprenenial culture), entreprenenial leader
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The control function of important functions in the system of government for several reasons , perhaps the most important of the magnitude of spending and spending in one of the tools adopted in the implementation of the control function.
Perhaps the most prominent stages of the development budget in terms of setup and use in the budget programs and performance , as specialized literature show its importance in strengthening financial and operationl
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3D models delivered from digital photogrammetric techniques have massively increased and developed to meet the requirements of many applications. The reliability of these models is basically dependent on the data processing cycle and the adopted tool solution in addition to data quality. Agisoft PhotoScan is a professional image-based 3D modelling software, which seeks to create orderly, precise n 3D content from fixed images. It works with arbitrary images those qualified in both controlled and uncontrolled conditions. Following the recommendations of many users all around the globe, Agisoft PhotoScan, has become an important source to generate precise 3D data for different applications. How reliable is this data for accurate 3D mo
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In this paper, variable gain nonlinear PD and PI fuzzy logic controllers are designed and the effect of the variable gain characteristic of these controllers is analyzed to show its contribution in enhancing the performance of the closed loop system over a conventional linear PID controller. Simulation results and time domain performance characteristics show how these fuzzy controllers outperform the conventional PID controller when used to control a nonlinear plant and a plant that has time delay.
Abstract:
The research sought to identify the crises that occurred during the research period and their reflection on the performance of the hotel Research sample as well as to identify the reality of auditing the hotel Research sample and the preparation of a performance audit program can be adopted in auditing the performance of hotels in light of crises, and the problem of the research lies in the lack of a program to audit the performance of hotels that takes into account the crises experienced by the hotel sector, The research was based on solving its problems on three hypotheses, the first is that the performance audit in light of the Covid-19 pand
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