• Title/Summary/Keyword: fiber analysis

Search Result 3,987, Processing Time 0.033 seconds

Partial Confinement Utilization for Rectangular Concrete Columns Subjected to Biaxial Bending and Axial Compression

  • Abd El Fattah, Ahmed M.;Rasheed, Hayder A.;Al-Rahmani, Ahmed H.
    • International Journal of Concrete Structures and Materials
    • /
    • v.11 no.1
    • /
    • pp.135-149
    • /
    • 2017
  • The prediction of the actual ultimate capacity of confined concrete columns requires partial confinement utilization under eccentric loading. This is attributed to the reduction in compression zone compared to columns under pure axial compression. Modern codes and standards are introducing the need to perform extreme event analysis under static loads. There has been a number of studies that focused on the analysis and testing of concentric columns. On the other hand, the augmentation of compressive strength due to partial confinement has not been treated before. The higher eccentricity causes smaller confined concrete region in compression yielding smaller increase in strength of concrete. Accordingly, the ultimate eccentric confined strength is gradually reduced from the fully confined value $f_{cc}$ (at zero eccentricity) to the unconfined value $f^{\prime}_c$ (at infinite eccentricity) as a function of the ratio of compression area to total area of each eccentricity. This approach is used to implement an adaptive Mander model for analyzing eccentrically loaded columns. Generalization of the 3D moment of area approach is implemented based on proportional loading, fiber model and the secant stiffness approach, in an incremental-iterative numerical procedure to achieve the equilibrium path of $P-{\varepsilon}$ and $M-{\varphi}$ response up to failure. This numerical analysis is adapted to assess the confining effect in rectangular columns confined with conventional lateral steel. This analysis is validated against experimental data found in the literature showing good correlation to the partial confinement model while rendering the full confinement treatment unsafe.

A Study on Optimum Design Analysis of Bolt Locations for Metal Joint Parts of Railway Composite Bogie Frames using Sub-modeling Method (서브모델링 기법을 이용한 철도차량 복합재 대차프레임의 금속재 체결부 볼트 위치 최적화 해석 연구)

  • Kim, Jun-Hwan;Shin, Kwang-Bok;Ko, Hee-Young;Kim, Jung-Seok
    • Composites Research
    • /
    • v.23 no.6
    • /
    • pp.19-25
    • /
    • 2010
  • This paper describes the optimum design of bolt locations for metal joint parts of railway bogie frame made of glass fiber/epoxy 4-harness satin woven laminate composite and PVC foam core. The optimum design analysis was done by sub-problem approximation method using Ansys Parameter Design Language(APDL). The sub-modeling method was introduced to conduct the detailed recalculation for the only target parts and reduce calculating time. The structural analysis for composite bogie frame was performed according to JIS E 4207. The results showed that the optimum design analysis using sub-modeling method was able to obtain faster and more precise results than that of the entire model by the control of mesh size for the target parts, and the maximum Von-Mises stress has been reduced in comparison with its original dimensions due to the optimum design of bolt locations.

Development of Main Wing Structure of Long Endurance Electric Powered UAV (24시간 장기체공 전기 동력 무인항공기 주익 구조 개발)

  • Park, Sang Wook;Shin, Jeong Woo;Park, Ill Kyung;Lee, Mu-Hyoung;Woo, Dae Hyun;Kim, Sung Joon;Ahn, Seok Min
    • Aerospace Engineering and Technology
    • /
    • v.12 no.1
    • /
    • pp.1-9
    • /
    • 2013
  • In order to increase endurance flight efficiency of long endurance electric powered UAV with solar cell, the light weight airframe design techniques are important. In this paper, the design of the main wing of electric powered UAV manufactured using Mylar film and fiber reinforced composite was conducted in order to achieve weight reduction and structural integrity of the structure. The shape of spar and size were determined using beam theory analysis. The finite element analysis of the wing was performed under various load condition derived from flight environment of EAV-2H. Finally, the static strength test of the main wing was conducted to verify structural integrity. It was found that the developed main wing weigh less than 42% than the previous EAV-2 and the main wing passed static strength test under ultimate load.

Comparision of Chemical Components of Ligusticum chuanzxiong HORT and Cnidium officinale MAKINO (토천궁과 일천궁의 화확성분 비교)

  • Hwang, Jinbong;Yang, Miok
    • Analytical Science and Technology
    • /
    • v.11 no.1
    • /
    • pp.54-61
    • /
    • 1998
  • Chemical components of domestic Ligusticum chuanxiong HORT and Cnidium officinale MAKINO were analyzed. Proximate analysis of each species showed crude protein 18.5% and 11.1%, crude lipid 5.9% and 6.2%, crude fiber 6.4% and 6.5%, crude ash 5.4% and 6.0%, and carbohydrate 63.7% and 70.2%, respectively. Contents of potassium which was found to be the most abundant mineral in both species were 1.8% and 3.0%, and those of sucrose were 0.4% and 0.3% respectively while neither fructose nor glucose were detected in each species. Major fatty acids in Ligusticum chuanxiong HORT and Cnidium officinale MAKINO were linoleic acid (60.7% and 61.2%), oleic acid (19.9% and 21.3%), palmitic acid (11.4% and 11.3%)(respectively) but there was no significant difference between two species. Glutamic acid was revealed as the most abandant amino acid in both species with 2.5% in Ligusticum chuanxiong HORT and 1.6% in Cnidium officinale MAKINO. Ligusticum chuanxiong HORT and Cnidium officinale MAKINO also were shown to be contained 0.0009% and 0.0005% vitamin $B_1$, and 0.6% and 0.7% tannin, respectively.

  • PDF

Products of Organic Cotton Brand and Color Analysis for Baby Wear-Comparative Analysis of Domestic and Japanese Brands (영아복을 위한 오가닉 코튼 브랜드의 제품디자인과 컬러 분석 -국내 브랜드와 일본 브랜드의 비교분석)

  • Park, Hea-Ryung;Jung, Jin-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.2
    • /
    • pp.678-687
    • /
    • 2014
  • Since the infants' skin is very weak and has poor adaptability to environment, they are vulnerable to dermatitis by chemicals. Organic cotton for baby wear with the same functions in inner and outer wears can be considered the most suitable fiber. Therefore, this study was to analyze products and colors of domestic and Japanese baby wear brands which use organic cotton. Of total six organic brands for baby wear, there are three domestic baby wear brands and three Japanese brands, and design colors of total 213 items were examined on the web. The results of comparative analysis showed that there were more Japanese brands than domestic brand in designs by uses. Color analysis showed that natural cotton color was preferred and YR colors are commonly used, but the colors of Japanese brands were widely distributed and those of domestic brands were relatively narrow.

Association between fish and shellfish, and omega-3 PUFAs intake and CVD risk factors in middle-aged female patients with type 2 diabetes

  • Kim, Hyesook;Park, Seokyung;Yang, Hyesu;Choi, Young Ju;Huh, Kap Bum;Chang, Namsoo
    • Nutrition Research and Practice
    • /
    • v.9 no.5
    • /
    • pp.496-502
    • /
    • 2015
  • BACKGROUND/OBJECTIVES: This study was performed to investigate the association between the dietary intake of fish and shellfish, and omega-3 polyunsaturated fatty acids (PUFAs) and cardiovascular disease (CVD) risk factors in the middle-aged Korean female patients with Type 2 diabetes (T2D). SUBJECTS/METHODS: A cross-sectional analysis was performed with 356 female patients (means age: 55.5 years), who were recruited from the Huh's Diabetes Clinic in Seoul, Korea between 2005 and 2011. The dietary intake was assessed by a validated semi-quantitative food frequency questionnaire and analyzed using the Computer Aided Nutritional Analysis program (CAN-Pro) version 4.0 software. RESULTS: In a multiple regression analysis after the adjustment for confounding factors such as age, BMI, duration of diagnosed T2D, alcohol consumption, fiber intake, sodium intake, and total energy intake, fish and shellfish intake of the subjects was negatively associated with triglyceride and pulse wave velocity (PWV). Omega-3 PUFAs intake was negatively associated with triglyceride, systolic blood pressures, diastolic blood pressures, and PWV. The multiple logistic regression analysis with the covariates showed a significant inverse relationship between the omega-3 PUFAs consumption and prevalence of hypertriglyceridemia [OR (95% CI) for greater than the median compared to less than the median: 0.395 (0.207-0.753)]. CONCLUSIONS: These results suggest that the consumption of fish and shellfish, good sources of omega-3 PUFAs, may reduce the risk factors for CVD in the middle-aged female patients with T2D.

Structural Safety Analysis of a Spherical Flight Simulator Designed with a GFRP-Foam Sandwich Composite (GFRP-폼 샌드위치 복합재료로 설계된 구체 비행 시뮬레이터의 구조 안정성 평가)

  • Hong, Chae-Young;Ji, Wooseok
    • Composites Research
    • /
    • v.32 no.5
    • /
    • pp.279-283
    • /
    • 2019
  • A flight training simulator of a fully spherical configuration is being developed to precisely and quickly control six degrees of freedom (Dof) motions especially with unlimited rotations. The full-scale simulator should be designed with a lightweight material to reduce inertial effects for fast and stable feedback controls while no structural failure is ensured during operations. In this study, a sandwich composite consisting of glass fiber reinforced plastics and a foam core is used to obtain high specific strengths and specific stiffnesses. T-type stainless steel frames are inserted to minimize the deformation of the sphere curvature. Finite element analysis is carried out to evaluate structural safety of the simulator composed of the sandwich sphere and steel frames. The analysis considers the weights of the equipment and trainee and it is assumed to be 200 kg. Gravity acceleration is also considered. The stresses and displacement acting on the simulator are calculated and the safety is assessed under two different situations.

Direct Numerical Simulation of Composite laminates Under low velocity Impact (저속충격을 받는 적층복합재료 평판의 직접 수치모사)

  • Ji, Kuk-Hyun;Kim, Seung-Jo
    • Composites Research
    • /
    • v.19 no.1
    • /
    • pp.1-8
    • /
    • 2006
  • Prediction of damage caused by low-velocity impact in laminated composite plate is an important problem faced by designers using composites. Not only the inplane stresses but also the interlaminar normal and shear stresses playa role in estimating the damage caused. But it is well known that the conventional approach based on the homogenization has the limit in description of damage. The work reported here is an effort in getting better predictions of dynamic behavior and damage in composite plate using DNS approach. In the DNS model, we discretize the composite plates through separate modeling of fiber and matrix for the local microscopic analysis. In the view of microscopic mechanics with DNS model, interlaminar stress behaviors in the inside of composite materials are investigated and compared with the results of the homogenized model which has been used in the conventional approach to impact analysis. Also the multiscale model based on DNS concept is developed in order to enhance the effectiveness of impact analysis, and we present the results of multiscale analysis considering micro and macro structures simultaneously.

Prediction of tenderness in bovine longissimus thoracis et lumborum muscles using Raman spectroscopy

  • Maria Sumampa Coria;Maria Sofia Castano Ledesma;Jorge Raul Gomez Rojas;Gabriela Grigioni;Gustavo Adolfo Palma;Claudio Dario Borsarelli
    • Animal Bioscience
    • /
    • v.36 no.9
    • /
    • pp.1435-1444
    • /
    • 2023
  • Objective: This study was conducted to evaluate Raman spectroscopy technique as a noninvasive tool to predict meat quality traits on Braford longissimus thoracis et lumborum muscle. Methods: Thirty samples of muscle from Braford steers were analyzed by classical meat quality techniques and by Raman spectroscopy with 785 nm laser excitation. Water holding capacity (WHC), intramuscular fat content (IMF), cooking loss (CL), and texture profile analysis recording hardness, cohesiveness, and chewiness were determined, along with fiber diameter and sarcomere length by scanning electron microscopy. Warner-Bratzler shear force (WBSF) analysis was used to differentiate tender and tough meat groups. Results: Higher values of cohesiveness and CL, together with lower values of WHC, IMF, and shorter sarcomere were obtained for tender meat samples than for the tougher ones. Raman spectra analysis allows tender and tough sample differentiation. The correlation between the quality attributes predicted by Raman and the physical measurements resulted in values of R2 = 0.69 for hardness and 0,58 for WBSF. Pearson's correlation coefficient of hardness (r = 0.84) and WBSF (r = 0.79) parameters with the phenylalanine Raman signal at 1,003 cm-1, suggests that the content of this amino acid could explain the differences between samples. Conclusion: Raman spectroscopy with 785 nm laser excitation is a suitable and accurate technique to identify beef with different quality attributes.

Comparative nutritional analysis for protopanaxadiol-enhanced genetically modified rice and its non-transgenic counterpart

  • Na Yeon Kim;Sung Dug Oh;Soo Yun Park;An Cheol Chang;Seong Kon Lee;Ye Jin Jang;So-Hyeon Baek;Yong Eui Choi;Jong-Chan Park;Doh Won Yun
    • Korean Journal of Agricultural Science
    • /
    • v.51 no.2
    • /
    • pp.239-249
    • /
    • 2024
  • In the assessment of the biosafety of genetically modified (GM) crops, a comparative approach to identifying similarities and differences between transgenic and non-transgenic crops is helpful in identifying potential safety and nutritional issues. In this study, we aimed to compare the nutritional composition of a protopanaxadiol-enhanced genetically modified rice (PPD GM rice) with its non-transgenic counterpart. The nutritional profile of PPD GM rice was assessed against that of the parental rice cultivar 'Dongjin' to ascertain nutritional equivalence. No differences were observed between PPD GM and Non-GM rice cultivar in proximate analysis, mineral content, and amino acid composition. Although significant differences were observed in crude fat, crude protein, total dietary fiber, and some minerals between PPD GM rice and Dongjin, these variances fell within the range suggested by common cultivars (Anmi and Nipponbare) and Organization for Economic Cooperation and Development (OECD) data. Similarly, while some amino acids showed significant differences, these metabolites did not deviate from the OECD range. Principal component analysis (PCA) was conducted using the nutritional analysis data of PPD GM rice and Dongjin. The results revealed that PPD GM rice and Dongjin were grouped according to their respective cultivation years. This suggests that the variability in the nutritional composition of PPD GM rice tends to resemble that of the parental rice cultivar 'Dongjin' rather than being solely attributed to genetic modification. Overall, our findings indicate that the nutritional composition of PPD GM rice is substantially equivalent to that of its non-transgenic counterpart.