• Title/Summary/Keyword: fiber analysis

Search Result 3,987, Processing Time 0.041 seconds

Image-Based Computational Modeling of Porous Matrix Composites and Calculation of Poroelastic Coefficients (다공성 기지를 갖는 복합재의 이미지 기반 전산 모형화 및 기공 탄성 계수 산출)

  • Kim, Sung Jun;Shin, Eui Sup
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.38 no.5
    • /
    • pp.527-534
    • /
    • 2014
  • Poroelastic analyses of fiber-reinforced composites were performed using image-based computational models. The section image of a porous matrix was analyzed in order to investigate the porosity, number of pores, and distribution of pores. The resolution, location, and size of the section image were considered to quantify the effective elastic modulus, poroelastic parameter, and strain energy density using the image-based computational models. The poroelastic parameter was calculated from the effective elastic modulus and pore pressure-induced strain. In addition, the results of the poroelastic analyses were verified through representative volume elements by simplifying various pore configurations and arrangements.

A Study on the Dynamic Characteristics of a Composite Beam with a Transverse Open Crack (크랙이 존재하는 복합재료 보의 동적 특성 연구)

  • 하태완;송오섭
    • Journal of KSNVE
    • /
    • v.9 no.5
    • /
    • pp.1019-1028
    • /
    • 1999
  • Free vibration characteristics of cantilevered laminated composite beams with a transverse non0propagating open carck are investigated. In the present analysis a special ply-angle distribution referred to as asymmetric stiffness configuration inducing the elastic coupling between chord-wise bending and extension is considered. The open crack is modelled as an equivalent rotational spring whose spring constant is calculated on the basis of fracture mechanics of composite material structures. Governing equations of a composite beam with a open crack are derived via Hamilton's Principle and Timoshenko beam theory encompassing transverse shear and rotary inertia effect. the effects of various parameters such as the ply angle, fiber volume fraction, crack depth, crack position and transverse shear on the free vibration characteristics of the beam with a crack is highlighted. The numerical results show that the natural frequencies obtained from Timoshenko beam theory are always lower than those from Euler beam theory. The presence of intrinsic cracks in anisotropic composite beams modifies the flexibility and in turn free vibration characteristics of the structures. It is revealed that non-destructive crack detection is possible by analyzing the free vibration responses of a cracked beam.

  • PDF

Plants Resources Investigation to Develop Supplement Food for Infant (영유아 및 아동의 보충식 개발을 위한 식물자원탐색)

  • Park, Hye-Jin;Ha, Joo-Young;Lee, Jong-Mee
    • Journal of the Korean Society of Food Culture
    • /
    • v.17 no.5
    • /
    • pp.646-652
    • /
    • 2002
  • In this study, we selected supplementary vegetable resources to develpe nutritious supplementary model of korean formula for infants and children, purchased and analyzed it to use with a model. We also referred to an old book about Korean vegetable resources and searched a form of vegetable resources. There are a lot of vegetable resources of various kinds which lied scattered in mountains and fields of our country. As for these, a beyond compare menstruation activity component is becoming clear with a lot of things. It is thought that depth search and study of these vegetable resources and practical application to a infant and child supplemen is desirable. Therefore, we choosed vegetable resources ; a Capsella brusapastoris, a Codonopsis lanceolata, Dandelion, a wild plant, a Tractylis ovata(dried), a Tractylis ovata(native), a Pine plant, a burdock, a JanDae, a Plantain, a HollpDae, which gathered in our country, and we analyzied priximate aomposition of sample (moisture, ash, total carbohydrate, crude fat, crude protein, dietary fiber) and micronutrient contents of sample (calcium, Iron, flavonoids, vitamin A, vitamin C, vitamin E).

A Study of The Stripe Patterns on The Fabric Design Since 2000 (년대 2000 이후 섬유디자인에 나타난 스트라이프 패턴 연구)

  • Han, Jung-Im
    • Journal of Fashion Business
    • /
    • v.15 no.2
    • /
    • pp.160-173
    • /
    • 2011
  • Stripe has been one of the all-time favorite fabric patterns so far and the usages have been widely applied of nearly everything ranging from everyday dress to interior fabrics. As the times change, patterns of this simple geometrical design have gradually become varied. Many effects of stripe patterns have allowed the patterns to be used in fabrics for fashion design and the patterns are considered fit for expressing individual characteristics. By studying theoretical background on categories of stripe patterns and the characteristics as a design and by researching the trends and properties exhibited in the modern fabric design, this paper will seek the potential of stripe patterns for design of a modern sense and the directions to express the patterns as a value-added design. This research was conducted through literature, books published at home and abroad, research papers and photographs on stripe patterns. Domestic magazines, web research, and photographs published since 2000 were studied for an analysis of the trends and characteristics of stripe patterns displayed in the modern fabric design. As the results, this research will explain the tendencies of stripe patterns on the modern fabric designs divided into several ways: simple and restrained modernity, active and sporty property, mannishness putting practicality forward-emerging as the status of women rises, and femininity emphasizing elegant women. The characteristics of the Plastic are categorized simplicity, rhythmicality, and Mixing of patterns.

Influence of Joint Mobilization on Formalin Induced Pain Prevention of Rats (관절가동술이 흰쥐의 포르말린 유도 통증 예방에 미치는 영향)

  • Kang, Jong-Ho;Kim, Eun-Kyung;Ro, Hyo-Lyun
    • Journal of the Korean Society of Physical Medicine
    • /
    • v.6 no.2
    • /
    • pp.207-213
    • /
    • 2011
  • Purpose: The purpose of this study was to determine the preventive effect of joint mobilization on biphasic pain response induced formalin test. Methods: Sprague-dawley rats(n=30) were ramdomly divided into the control group without intervention, sham control group with application of hand contact without mobilization, joint mobilization group with application of hand contact with mobilization. Joint mobilization of knee procedure involved an grade III extension mobilization basically with anterior-posterior gliding of the tibia on the femur. Formalin injection caused biphasic pain response which is lated for 60 minute. The first phase result from primary afferent sensory fiber, wheareas the second phase has been proposed to central sensitization in the central nervous system. Behavioral analysis was performed by digital camera after 5% formalin subcutaneous injection into the dorsal foot. Results: Pain response of joint mobilization group show significant lower than control gorup and sham control group. Conclusion: This result suggest that pre-application of joint mobilization may be effective intervention to prevent the formalin induced pain.

Differences in Food and Nutrient Intake Associated with Smoking Status of Korean

  • Kim, Youngok
    • Journal of Community Nutrition
    • /
    • v.4 no.1
    • /
    • pp.22-28
    • /
    • 2002
  • The purpose of this study was to investigate the differences in food and nutrient intake by smoking status among Korean. Food and nutrient intake in relation to smoking status was studied in 7,370 adults, aged 20 years and older in 1998 Korean National Health and Nutrition Survey, in which 24 hour recall method was used for dietary survey. Information of subject's smoking status was collected by interview as a part of health behavior survey. Analysis of variance was used to test the differences in food and nutrition intake among subjects following after Duncan's multiple range test among four different smoking exposure categories. Food intake of male ex-smoker was the highest in most of the food groups among the four groups of daily current smoker, occasional current smoker, ex-smoker and never smoker. There was significant differences observed in food intake of sugar, fruits, beverage, seasoning by the smoking status. It had been also observed that significantly high intake of energy from carbohydrate in non smoker compare to current smoker especially in male subjects. Fiber and vitamin C intake was also higher among non-smoker (never smoker and ex-smoker) than current smoker. In general, food and nutrient intake pattern of ex-smoker resembled those of never smoker than those of current smoker. Not likely the observation from European and American studies, fat intake was not statistically different between smoker (current) and non-smoker (ex-smoker and never smoker) among Korean.

An Experimental Study on the Flexural Fatigue Behavior of Glass fiber Reinforced Plastec Pipes (유리섬유 보강 플라스틱관의 휨 피로 거동에 관한 실험적 연구)

  • Jang, Dong-Il;Go, Jae-Won
    • Korean Journal of Materials Research
    • /
    • v.4 no.2
    • /
    • pp.219-226
    • /
    • 1994
  • In the comparison result of residual strain calculated from the load-strain curve under the repeated loading cycles, it was found that the larger the laminates is, the larger the stiffness of GFRP pipes under fatigue load is. This phenomenon is true until the fatigue failure. According to the S-N curves drawn by the regression analysis on the fatigue test results, the fatigue strength for percentage of the static ultimate strength increases by increasing the laminates of GFRP pipes. The fatigue strength for 2, 000, 000 repeated loading cycles In GFRP pipes with the laminates varing 15, 25, 35 shows 75.2%, 79.5%, 84.2% on the static ultimate strength, respectively.

  • PDF

A Study on the Strength Properties of FRP Member for Making Personal Disaster Shelters in Rural Area (농산촌 재난대피시설 제작을 위한 FRP 부재의 강도특성에 관한 연구)

  • Kim, Jung Meyon;Hwang, Dea Won;Lim, Hyun Taek;Park, Sung Yong;Yeon, Kyu Seok;Kim, Yong Seong
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.58 no.2
    • /
    • pp.73-82
    • /
    • 2016
  • This study is about development of personal disaster shelters for minimization of the casualties caused by the landslide and steep slope collapse. The objectives of present research is the selection of disaster evacuation facilities utilizing FRP (Fiber Reinforced Plastic) material. For the proper assessment of FRP member, several layers by strength test and the three-dimensional numerical analysis of these FRR member was carried out. As a result, the personal disaster evacuation facility utilizing FRP materials, was found to be of a material that is able to protect the weak person at the time of the collapse of the landslides and steep slopes.

The Physicochemical Characteristics of PET Fabrics Treated with Low Temperature Glow Plasma and Atmospheric Corona Discharge (진공 저온 플라즈마와 대기압 코로나 방전가공 PET 직물의 물리화학적 특성)

  • Ma, Jaehyuk;Yang, Jinyoung;Koo, Kang;Yang, Hyun A;Park, Youngmi
    • Textile Coloration and Finishing
    • /
    • v.26 no.3
    • /
    • pp.201-208
    • /
    • 2014
  • The high value-added functionality for synthetic fiber can be considered through a plasma enhanced treatment. In this study, PET(Polyethyleneterephthalate) was treated with a glow plasma and corona treatment. Surface characteristics of treated fabric were investigated using electron scanning microscopy(SEM), contact angle, X-ray photoelectron spectroscopy(XPS), tensile and adhesion strength. It was found that the contact angle showed $85.5^{\circ}$ for untreated fabric, $0^{\circ}$ for plasma and corona treatment at the condition of 200W for 7min. By XPS analysis, atomic ratio of O 1s/C 1s was increased from 0.27 to 0.43 by glow plasma and 0.27 to 0.41 by corona treatment at 200W for 7min, respectively. Glow plasma and corona treatment did not significantly change the tensile strength of PET fabric. Adhesion strength showed a substantial enhancement for the surface treated with the glow plasma, while corona treatment was adversely affected.

Analysis on the Preservation of Scalp Collected from Full-Term Baby Mummy of Medieval Joseon Dynasty (조선시대 태아 미라 두피조직의 보존상태 분석)

  • Chang, Byung-Soo
    • Applied Microscopy
    • /
    • v.38 no.2
    • /
    • pp.135-140
    • /
    • 2008
  • In this study, I investigated on the ultrastructure of scalp skin from full term baby mummy by using transmission and scanning electron microscopy. The baby mummy was found within the uterus of a 16th century (Joseon Dynasty) mummified woman aged 20${\sim}$30 years old. In scanning electron microscopic study, I found that the outer surface of scalp skin containing of sweat gland and stratum corneum are well preserved. The skin of the scalp measured about 1 mm in thickness and the epidermis was well distinguished from the dermis. In transmission electron microscopy, the shape and structure of the epithelial cells were not confirmed. I also observed well preserved collagen fibers composed of collagen fibrils with cross banding pattern ultrastructurally. But, the other connective cells were not observed due to decomposition of the dermis.