• 제목/요약/키워드: Capacity increase method

검색결과 1,109건 처리시간 0.026초

GFRP 보강근을 사용한 콘크리트 보의 휨파괴 거동 (Flexural Behavior of Concrete Beams Reinforced with GFRP Bars)

  • 하상훈;김정규;황금식;어석홍
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
    • /
    • pp.339-342
    • /
    • 2005
  • This paper presents flexural test results of concrete beams reinforced with GFRP and conventional steel reinforcement for comparison. The beams were tested under static loading to investigate the effects of reinforcement ratio and compressive ,strength of concrete on cracking, deflection, ultimate capacity and mode of failure, This study attempts to establish a theoretical basis for the development of simple and rational design guideline. Test results show that ultimate capacity increases as the reinforcement ratio and concrete strength increase. The ultimate capacity increased up to $8\%-25\%$ by using high strength concrete. The deflection at maximum load of GFRP reinforced beams was about three times that of steel reinforced beams. For GFRP-reinforced beams, the ACI code 440 design method resulted in conservative flexural strength -estimates.

  • PDF

Crystallinity and Battery Properties of Lithium Manganese Oxide Spinel with Lithium Titanium Oxide Spinel Coating Layer on Its Surface

  • Ji, Mi-Jung;Kim, Eun-Kyung;Ahn, Yong-Tae;Choi, Byung-Hyun
    • 한국세라믹학회지
    • /
    • 제47권6호
    • /
    • pp.633-637
    • /
    • 2010
  • In this study, lithium manganese oxide spinel ($LiMn_{1.9}Fe_{0.1}Nb_{0.0005}O_4$) as a cathode material of lithium ion secondary batteries is synthesized with spray drying, and in order to increase its crystallinity and electrochemical properties, the granulated $LiMn_{1.9}Fe_{0.1}Nb_{0.0005}O_4$ particle surface is coated with lithium titanium oxide spinel ($Li_4Ti_5O_{12}$) through a sol-gel method. The granulated particles present a higher tap density and lower specific surface area. The crystallinity and discharge capacity of the $Li_4Ti_5O_{12}$ coated material is relatively higher than uncoated material. With the coating layer, the discharge capacity and cycling stability are increased and the capacity fading is suppressed successfully.

H형강 프레임으로 보강한 철근 콘크리트 골조의 내진성능 평가 (Seismic Capacity of Reinforced Concrete Frames Retrofitted with H-beam Frame)

  • 김민숙;최호순;송승언;이영학
    • 한국지진공학회논문집
    • /
    • 제17권3호
    • /
    • pp.127-132
    • /
    • 2013
  • This study proposed proposes a retrofitting method using an H-beam frame to improve the seismic performance of non-seismic designed reinforced concrete frames. To evaluate the seismic performance with the H-beam frames, a cyclic lateral load test was performed and the experimental result was compared with the bared frame, and a masonry infilled RC frame. The results was were analyzed regarding aspects of the load-displacement hysteresis behavior, effective stiffness, displacement ductility, and cumulative energy dissipation. AlsoIn addition, it was possible to prove both an increase of in the maximum load capacity, effective stiffness, and energy dissipation capacity using the H-beam frame.

유전자 알고리즘을 이용한 깊은 홈 볼 베어링의 고부하용량 설계 (Genetic Algorithm Based Design of Beep Groove Ball Bearing for High-Load Capacity)

  • 윤기찬;조영석;최동훈
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 1999년도 제30회 추계학술대회
    • /
    • pp.167-173
    • /
    • 1999
  • This paper suggests a method to design the deep groove ball bearing for high-load capacity by using a genetic algorithm. The design problem of ball bearings is a typical discrete/continuous optimization problem because the deep groove ball bearing has discrete variables, such as ball size and number of balls. Thus, a genetic algorithm is employed to find the optimum values from a set of discrete design variables. The ranking process is proposed to effectively deal with the constraints in genetic algorithm. Results obtained fer several 63 series deep groove ball bearings demonstrated the effectiveness of the proposed design methodology by showing that the average basic dynamic capacities of optimally designed bearings increase about 9~34% compared with the standard ones.

  • PDF

보강재를 사용한 철근콘크리트 보의 휨·전단내력에 관한 실험적연구 (An Experimental Study on Flexural and Shear Strength of Reinforced Concrete Beam Using Reinforcing Materials)

  • 홍상균;은희창;박기철;정헌수
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제1권1호
    • /
    • pp.65-73
    • /
    • 1997
  • In this paper, It is the effect of using fiber sheet (Carbon Fiber Sheet & Aramid Fiber Sheet) and Steel Plate for reinforced concrete beam. 25 specimens are tested, 16 specimens are for bending capacity and the other are for shear capacity. In the case of bending testing, the kind and quantity of the reinforcement materials, the bondage and the existence of crack were selected as experimental variables. In the case of shear testing, It is testified the effect of reinforcement with the variables of the method of reinforcement (side type and U type). As a result, Using the reinforcing materials can increase the capacity of bending and shear stress.

  • PDF

Settlement analysis of pile cap with normal and under-reamed piles

  • Kumar, Madisetti Pavan;Raju, P. Markandeya;Jasmine, G. Vincent;Aditya, Mantini
    • Computers and Concrete
    • /
    • 제25권6호
    • /
    • pp.525-535
    • /
    • 2020
  • The use of pile foundations has become more popular in recent years, as the combined action of the pile cap and the piles can increase the bearing capacity, reduce settlement, and the piles can be arranged so as to reduce differential deflection in the pile cap. Piles are relatively long, slender members that transmit foundation loads through soil strata of low bearing capacity to deeper soil or rock strata having a high bearing capacity. In this study analysis of pile cap with considering different parameters like depth of the pile cap, width and breadth of the pile cap, type of piles and different types of soil which affect the behaviour of pile cap foundation is carried out by using Finite Element Software ANSYS. For understanding the settlement behaviour of pile cap foundation, parametric studies have been carried out in four types of clay by varying pile cap dimensions with two types of piles namely normal and under-reamed piles for different group of piles. Furthermore, the analysis results of settlement and stress values for the pile cap with normal and under-reamed piles are compared. From the study it can be concluded that settlement values of pile cap with under-reamed pile are less than the settlements of pile cap with normal pile. It means that the ultimate load bearing capacity of pile cap with under-reamed piles are greater than the pile cap with normal piles.

만성 뇌졸중 환자의 항산화능에 영향을 주는 요인에 관한 연구 (Antioxidant Capacity and Associated Factors during the Chronic Phase after Stroke)

  • 최승혜;곽충실;최스미
    • Journal of Korean Biological Nursing Science
    • /
    • 제16권1호
    • /
    • pp.52-59
    • /
    • 2014
  • Purpose: The purpose of this study was to investigate antioxidant capacity and relating factors including gender, obesity, lifestyle factors, and nutrient intake in chronic stroke patients. Methods: A total of 188 chronic stroke patients who visited a medical center in Seoul participated in the study. A structured questionnaire was used to assess their clinical characteristics and lifestyles. Blood samples were collected for ferric reducing ability of plasma (FRAP) for antioxidant capacity. Dietary intake of the patients were obtained for 2 days by 24 hours recall method. Results: The mean FRAP was $392.0{\mu}mol/L$. According to the hierarchical multiple regression analysis, the factors related to high FRAP were male sex (p=.036), alcohol drinking (p=.013), and calorie intake deficiency (p=.005). Conclusion: We found that antioxidant capacity was related to lifestyle factors including alcohol drinking, and calorie intake in chronic stroke patients. A tailored strategy is needed to increase antioxidant capacity according to gender and lifestyles in the chronic phase of stoke patients.

입원 호흡재활 프로그램이 만성 폐질환자의 호흡곤란, 운동능력과 건강관련 삶의 질에 미치는 효과 (Effects of an Inpatient Pulmonary Rehabilitation Program on Dyspnea, Exercise Capacity, and Health Related Quality of Life for Patients with Chronic Lung Disease)

  • 이창관
    • 대한간호학회지
    • /
    • 제37권3호
    • /
    • pp.343-352
    • /
    • 2007
  • Purpose: The purpose of this study was to examine the effects of an inpatient pulmonary rehabilitation program on dyspnea, exercise capacity, and health related quality of life in inpatients with chronic lung disease. Method: This quasi experimental study was designed with a nonequivalent control group pre-post test time series. Twenty three patients were assigned to the experimental group and nineteen to the control group. The inpatient pulmonary rehabilitation program was composed of upper and lower extremity exercise, breathing retraining, inspiratory muscle training, education, relaxation and telephone contacts. This program consisted of 4 sessions with inpatients and 4 weeks at home after discharge. The control group was given a home based pulmonary rehabilitation program at the time of discharge. The outcomes were measured by the Borg score, 6MWD and the Chronic Respiratory Disease Questionnaire(CRQ). Results: There was a statistically significant difference in dyspnea between the experimental group and control group, but not among time sequence, or interaction between groups and time sequence. Also significant improvements in exercise capacity and health related quality of life were found only in the experimental group. Conclusions: An Inpatient pulmonary rehabilitation program may be a useful intervention to reduce dyspnea, and increase exercise capacity and health related quality of life for chronic lung disease patients.

대학생들의 예·복습 시간이 Gross Motor Function Measure의 일부 항목평가 능력에 미치는 영향 (The Effect of The preparation and Review Times on the Some Items of The gross Motor Function Measure evaluation capacity of the College Students)

  • 이한숙;김은주
    • 대한물리의학회지
    • /
    • 제10권1호
    • /
    • pp.99-105
    • /
    • 2015
  • PURPOSE: The purpose of this study was to investigate the differenceof GMFM evaluationcapacity according to the preparation and review times on the college students. METHODS: 58 subjects among physical therapymajor studentswere recruited. The group was constructed the fourgroupsbypreparation and review times. The firstgroup was less than 1hour, the second group wasmore than 1 hour ~ less than 2 hours, the third group was more than 2 hours ~ less than 3 hours, the fourth group was more than 3 hours that was preparation and reviewtimes. The students were performed GMFM evaluation capacity after they learned the normal motor development for 5 weeks and evaluation method. They continued the preparation and review learning about the lesson during 5 weeks. RESULTS: The group of more than 3 hours was the highest and next order was the group of more than 1 hour ~ less than 2 hours, group of less than 1hour on GMFM evaluation capacity. CONCLUSION: Preparation and review times improved the GMFM evaluation capacity of students. Therefore, Emphasizing the preparation and review of learning is proper way to increase the evaluation capacity. In addition, the professor should create the appropriate teaching strategies using preparation and review times to upgrade a learner's ability.

소형 압력 토조내에 타입된 말뚝의 인발 거동과 극한 인발 지지력 결정에 관한 연구 (Study on Pullout Behavior and Determination of Ultimate Uplift Capacity of Pile Driven in Small Pressured Chamber)

  • 최용규
    • 한국지반공학회지:지반
    • /
    • 제11권2호
    • /
    • pp.19-28
    • /
    • 1995
  • 소형 압력 토조(small pressure chamber)를 이용하여 포화된 사질토에 타입된 폐단 강관 말뚝의 인발거동 특성을 연구하였다. 소형 압력 토조 시험에서는 인발 하중이 인발변위와 함께 증가하다가 급작스러운 미끄러짐 변위가 발생되는 현상이 2-3회 반복되다가 완전 인발파괴에 이르게 되는데, 이때 첫번째 미끄러짐 변위가 발생하는 하중의 크기를 극한 인발 지지력으로 정의할 수 있다. 또한, 소형 압력 토조 시험에서는 미세한 시험 조건에 의해서도 극한 인발 지지력의 크기가 50% 이상의 오차를 나타낼 수도 있으므로 모형 지반을 형성할 때마다 인발 재하 시험에 의하여 극한 인발 지지력을 결정하여 사용하는 것이 좋을 것으로 판단되며, 이때 1차 인발 시험에 의해 교란된 지반의 상태는 모형 말뚝의 크기에 적합한 타격에너지를 가해주어 회복시킬 수 있다.

  • PDF