Probabilistic elastic-plastic analysis of repaired cracks with bonded composite patch

Mourad Chama,Belaïd Mechab,Khacem Kaddouri,Djelloul Slimani 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.20 No.6

The objective of this work was to evaluate the ductile cracked structures with bonded composite patch used in probabilistic elastic plastic fracture mechanics subjected to tensile load. The finite element method is used to analyze the stress intensity factors for elastic case, the effect of cracks and the thickness of the patch (<i>e_r</i>) are presented for calculating the stress intensity factors. For elastic-plastic the Monte Carlo method is used to predict the distribution function of the mechanical response. According to the obtained results, we note that the stress variations are important factors influencing on the distribution function of (J/Je).

A new formulation of the J integral of bonded composite repair in aircraft structures

Nassim Serier,Belaïd Mechab,Rachid Mhamdia,Boualem Serier 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.5

A three-dimensional finite element method is used for analysis of repairing cracks in plates with bonded composite patch in elastic and elastic plastic analysis. This study was performed in order to establish an analytical model of the J-integral for repair crack. This formulation of the J-integral to establish models of fatigue crack growth in repairing aircraft structures. The model was developed by interpolation of numerical results. The obtained results were compared with those calculated with the finite element method. It was found that our model gives a good agreement of the J-integral. The arrow shape reduces the J integral at the crack tip, which improves the repair efficiency.

Modeling and Hybrid Control of a Constrained Rigid Robotic System

Amine CHAÂBOUNI,Ines BELAÏD DLIMI,Hichem KALLEL 보안공학연구지원센터 2012 International Journal of Control and Automation Vol.5 No.3

Articles : "Revealed" Comparative Advantage in Japan and the United States

( Bela Balassa ),( Marcus Noland ) 세종대학교 경제통합연구소 1989 Journal of Economic Integration Vol.4 No.2

This paper examines the changing comparative advantage of Japan and the United States. Indices of "revealed" comparative advantage have been derived for 57 primary and 167 manufactured product categories. These indices have further been aggregated for 20 commodity groups. Data are further provided on high technology products. During the period 1967-1983 Japan`s pattern of specialization is found to have changed dramatically with Japan shifting from specialization in unskilled labor intensive goods to human capital intensive products while its comparative disadvantage increased in natural resources intensive products. The United Slates maintained its specialization in physical capital and human capital intensive goods while increasing its comparative advantage in natural resource intensive products. Both countries increased their comparative advantage in high techonlogy products.

Foreword(10권)

( Bela Kadar ),( Jeno Hamori ) 연세대학교 동서문제연구원 1990 East and West Studies Series Vol.10 No.-

Articles : Japanese Trade Policies Towards Developing Countries

( Bela Balassa ) 세종대학교 경제통합연구소 1986 Journal of Economic Integration Vol.1 No.1

실내 시공시 손상시험에 의한 HDPE 지오멤브레인의 기계적 특성 및 응력균열거동 해석

Belas Ahmed Khan,박주희(Ju Hee Park),김성희(Sung Hee Kim),장용채(Yong Chai Chang),오태환(Tae Hwan Oh),류원석(Won Seok Lyoo),전한용(Han Yong Jeon) 한국고분자학회 2011 폴리머 Vol.35 No.3

표면이 매끄럽고 돌기가 있는 2가지 HDPE 지오멤브레인 덤벨형 시료에 두께 10% 간격으로 10∼90% 깊이의 노치를 가하여 실험에 사용하였다. ISO 10722에 의거하여 부가하중 횟수를 변화시켜 시공시 손상의 실내 모사시험을 HDPE 지오브레인에 실시하였으며, 부가하중 횟수가 시공시 손상에 미치는 영향을 비교하였다. 항복응력과 변형률은 노치 깊이가 커짐에 따라 감소하였다. 손상된 그리고 노치를 가한 지오멤브레인을 응력균열시험에 사용하였으며, 50±1 ℃에서 pH 4와 12 용액에 침지시켜 항복응력 변화에 따른 응력균열저항성을 NCTL 시험을 통하여 고찰하였다. 인장강도의 35% 이상에서 지오멤브레인은 응력균열에 취약함을 나타냈으며, 손상을 받은 그리고 노치를 가한 지오멤브레인 모두 같은 경향을 나타내었다. 특별히 노치를 가한 지오멤브레인의 경우 각각의 응력균열 시험조건에서 시공에 의해 손상된 지오멤브레인보다 낮은 강도를 나타내었다. Two smooth and textured surfaced HDPE geomembranes (GMs) were cut into dumbbell shape and notched where depth of the notch produced a ligament thickness of 10% to 90% of the nominal thickness with the specimen at 10% interval. A series of laboratory simulation test for installation damage were carried out at different loading cycles on HDPE GMs in accordance with ISO 10722 test method and the effect of number of loading cycle on installation damage was compared. It was found that yield stress and elongation at yield point decreased gradually as the notch depth was increased. Both installation damaged and notched, GMs were used to understand stress crack behavior and this behavior was observed through NCTL test at 50±1 ℃ at different yield stresses immerging in pH 4 and pH 12 buffer solutions. Over 35% tensile load, GMs became vulnerable to stress cracking. Both damaged and notched GMs showed the same trend. Especially, notched GMs showed less strength than installation damaged GMs at every stress cracking test condition.

Multimedia Educational Material and Remote Laboratory for Sliding Mode Control Measurements

Bela Takarics,Gabor Sziebig,Bjørn Solvang,Peter Korondi 전력전자학회 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.6

The paper presents a multimedia educational program of DC servo drives for distant learning with a special emphasis on sliding mode control. The program contains of three parts: animation, simulation and internet based measurement. The animation program explains the operation of DC motors, gives its time- and frequency-domain equations, transfer functions and the theoretical background necessary for controller design for DC servo motors. The simulation model of the DC servo motor and the controller can be designed by the students based on the animation program. The students can also test their controllers through the internet based measurement, which is the most important part from engineering point of view. After the measurements are executed, the students can download the measured data and compare them to the simulation results.

Conduction mechanisms in porous Si LEDs

Bela Szentpali,Tibor Mohacsy,Istvan Barsony 한국물리학회 2006 Current Applied Physics Vol.6 No.2

Diode-like structures were prepared from p- and n-type Si, in which porous Si layers were sandwiched between the crystalline Si and the evaporated Al top contact. The current–voltage characteristics were investigated in that bias polarity, at which electroluminescence occurs. It was found that the characteristics follow the Fowler–Nordheim tunneling process for both type of devices. The tunneling occurs through the heterojunction barrier at the crystalline-porous interface. The leakage current experienced at low biases in the p-type structure is attributed to trap-assisted tunneling; its saturation character was pointed out by low-frequency noise measurements.

Marketing Feng Shui to Asia: A Case Study

Bela Florenthal,Noriko Yagi,Hongjiang Xu 한국마케팅학회 2009 ASIA MARKETING JOURNAL Vol.11 No.2

Feng Shui practice is very popular in East Asia and has been rapidly adopted by the population of the West. As Feng Shui involves knowledge of object placement, it opens opportunities to market Feng Shui knowledge and products. This paper presents an analysis of a successful Feng Shui enterprise, World of Feng Shui (WOFS), that has been established by a well-known Feng Shui expert Lillian Too and her daughter Jennifer Too. The enterprise’s marketing strategies and tactics are tied to the theoretical concept of social influence, widely researched in the consumer behavior literature. The three types of social influence (informational, utilitarian, and value-expressive) are examined in relation to WOFS’ marketing strategies using secondary data material. The main results indicate that the strategies of WOFS enterprise address all three types of social influence. The articles generated on- and off-line can be mostly associated with the informational influence. The off- line activities such as events, courses/workshops, and TV shows are also informational in nature. The Q & A sections/ postings can be considered as representative of the utilitarian influence. They give experts (e.g., Lillian Too) the opportunity to provide individuals with problem-specific recommendations. Mega-mall website provides the value-expressive influence as purchase and consumption of the Feng Shui products is most susceptible to this type of influence. In terms of implications, WOFS enterprise strategies are suitable not only for consumes but also for business executives in Asia and in the West as architects, designers, and homeowners across continents use Feng Shui practices for building placements and decoration of dwellings and workplaces. Feng Shui practice has some limitations such as conflicting opinions of experts and increased complexity when the dimension of time is taken into consideration. Still, Feng Shui as a practice is growing globally adjusting itself to regional and cultural challenges.