http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Naamane Benhassine,Ammar Haiahem,Benyebka Bou-Said 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1
During braking, a heat flow is generated by friction and heated the brake components, the heating causes thermal expansion in the disc and the pads and these expansions alternate the contact. This paper proposes a transient thermomechanical simulation of friction by the finite element method of disc/pads of a sport cars brake using ABAQUS. In this comparative study, three different ceramic composite materials (A359/SiC p20, Al6061/SiC, C/C-SiC) are used for the disc which is in friction with organic (C/C) lining bonded to steel back plates of the brake pads. This will allow us to emphasize the importance of the distribution and the variation of the temperature on the contact pressure and the stress field and the braking torque.
Antoine E. Naaman,김민경,이차돈 中央大學校 建設環境硏究所 1998 環境科學硏究 Vol.9 No.1
Recently, application of composite materials such as fiber reinforced concretes(FRC) and fiber reinforced plastics(FRP) in conjunction with conventional structural components have been of the main research areas. A proper use of advanced composite materials requires understanding their resistance mechanism and failure mode when they are applied to structures or their components, This can be achieved either experimentally or analytically. In modeling , due consideration must be given to the different constitutive behaviors of composite beams, various possible combinations of placement of composite materials, and reasonable reproduction of overall behavior of composite structures. The analytical model is developed in order to predict the nonlinear flexural responses of various beams including boned and unbonded prestressed concrete beams which contain advanced composite materials either in matrices or in reinforcing bars. The block concept is developed, which can be regarded as an intermediate modeling method between the couple method with one block and the layered method with multiple sliced layers in a section. The concept is adopted for its effectiveness in considering cementitious composite matrices cast in part as blocks in a beam section. In order ot find a particular deflection point of a beam under load, solutions to the 2N-variables(top and bottom strains at each section along beam axis having N sections for analysis) are found numerically by using approximate N-force equilibrium equations and N-moment equilibrium equations. The model can successfully predict the flexural behavior of variously reinforced concrete beams with composite materials as well as strengthened beam with FRP sheets at their soffit.
Kim, Dong-Joo,Naaman, Antoine E.,El-Tawil, Sherif Korea Concrete Institute 2009 International Journal of Concrete Structures and M Vol.3 No.2
This paper provides a brief summary of the performance of an innovative slip hardening twisted steel fiber in comparison with other fibers including straight steel smooth fiber, high strength steel hooked fiber, SPECTRA (high molecular weight polyethylene) fiber and PVA fiber. First the pull-out of a single fiber is compared under static loading conditions, and slip rate-sensitivity is evaluated. The unique large slip capacity of T-fiber during pullout is based on its untwisting fiber pullout mechanism, which leads to high equivalent bond strength and composites with high ductility. Due to this large slip capacity a smaller amount of T-fibers is needed to obtain strain hardening tensile behavior of fiber reinforced cementitious composites. Second, the performance of different composites using T-fibers and other fibers subjected to tensile and flexural loadings is described and compared. Third, strain rate effect on the behavior of composites reinforced with different types and amounts of fibers is presented to clarify the potential application of HPFRCC for seismic, impact and blast loadings.
Omar El-aajine,Azeddine Naamane,Mohammed Radouani,Benaissa El Fahime 한국유체기계학회 2022 International journal of fluid machinery and syste Vol.15 No.3
The aim of the present study is two-fold. Firstly, it attempts to solve the asymptotic model of the 2D stationary potential flow of a supersonic viscous fluid over thin airfoils. In the case of a high Re number: = (105), and a free stream Mach number of ∞ = 1.45, the asymptotic solution is built using the new successive complementary expansion method. The theoretical Mach number of the flow is estimated in the outer inviscid zone along the airfoil surface, and a correction term is added to account for the viscous boundary layer effect in order to get an accurate approximation throughout the whole domain. Secondly, for comparison purposes, numerical simulations of the NACA 43013 airfoil were run for the Mach number distribution in each area. On the one hand, when compared to numerical simulations, the asymptotic supersonic laminar viscous flow solution shows good agreement for the laminar boundary layer but begins to diverge slightly from = , .At this point, the laminar-turbulent transition starts, then the turbulent boundary layer develops towards the trailing edge. On the other hand, the Mach number distribution for the outer inviscid region matches the simulation and illustrates the change in velocity upon interaction with both the detached shock wave and the expansion waves.
Dong-Joo Kim,Antoine E. Naaman,Sherif El-Tawil 한국콘크리트학회 2009 International Journal of Concrete Structures and M Vol.3 No.2
This paper provides a brief summary of the performance of an innovative slip hardening twisted steel fiber in comparison with other fibers including straight steel smooth fiber, high strength steel hooked fiber, SPECTRA (high molecular weight polyethylene) fiber and PVA fiber. First the pull-out of a single fiber is compared under static loading conditions, and slip ratesensitivity is evaluated. The unique large slip capacity of T-fiber during pullout is based on its untwisting fiber pullout mechanism, which leads to high equivalent bond strength and composites with high ductility. Due to this large slip capacity a smaller amount of T-fibers is needed to obtain strain hardening tensile behavior of fiber reinforced cementitious composites. Second, the performance of different composites using T-fibers and other fibers subjected to tensile and flexural loadings is described and compared. Third, strain rate effect on the behavior of composites reinforced with different types and amounts of fibers is presented to clarify the potential application of HPFRCC for seismic, impact and blast loadings.