• Title/Summary/Keyword: Time-varying stress

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A Study on the Instrument Panel Design Trend for Automobile Interior (자동차 인테리어의 인스트루먼트 패널 디자인 경향 연구)

  • Cho, Kyung-Sil;Lee, Myung-Ki
    • Archives of design research
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    • v.18 no.4 s.62
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    • pp.129-138
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    • 2005
  • Until the early part of the 1990s, interior design has never been thought important by car makers. Repeated attempts have been made to systemize a technical structure, such as layout, driving method, and size, and the car's interior design has been developed by in simple comparison with the exterior design. In the 1990s, however, this trend began to change because consumers began spending more time in their cars, so the motive of the technology development became that of giving comfort and functional satisfaction to the customers. Observing how a person spends inside his or her car and considering the latest trends in car interiors have made a consumer-oriented sense of value i.e., intensifying the personality of the car's interior design and considering the emotional makeup of the consumer factor in the acquisition of a strategic brand identity. These days, car interiors assume a new concept every year due to the constant change in various factors, and the application of a high-tech design, with a sensing function and a navigation system, to achieve driverless running, is being raised as a key trend element technology for the future. Now, at the present when multilateral concept applications of design are attempted under the direct influences from other fields such as product design, fashion and furniture, I would like to lay stress on investigating and analysing the changes in car interior design varying with the background of the times and formative characteristics from the object point of view. On this study, I would like to compare the background of the times and flow of car interior design with priority given to crash pad and would like to attempt to present the direction of the future car interior design together with diversifying major technical factors.

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Characteristic of Buckling and Ultimate Strength of the Perforated Stiffened Plate (유공보강판의 좌굴 및 극한강도 특성에 관한 연구)

  • Park Joo-Shin;Ko Jae-Yong;Oh Kyoung-Gun
    • Journal of Navigation and Port Research
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    • v.30 no.6 s.112
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    • pp.439-446
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    • 2006
  • In ship structures many of the structural plates have cutouts, for example, at inner bottom structure, girder, upper deck hatch, floor and dia-frame etc. In the case where a plate has a cutout it experiences reduced buckling and ultimate strength and at the same time the in-plane stress under compressive load produced by hull girder bending will be redistributed In general, actual ship structure adopted reinforcement of stiffener around the cutout in order to preventing from buckling so it need to examine a buckling and ultimate strength behaviour considering a cutout because In many ship yards used class rule for calculating buckling strength but it is difficult to evaluate perforate stiffened plate with random size. In the present paper, we investigated several kinds of perforated stiffened model from actual ship and then was performed finite element series analysis varying the cutout ratio, web height, thickness and type of cross-section using commercial FEA program(ANSYS) under compressive load.

Wavelength Interrogation Technique for Bragg Reflecting Strain Sensors Based on Arrayed Waveguide Grating (도파로 어레이 격자를 이용한 광섬유 브래그 스트레인 센서의 반사파장 신호 복원 기술)

  • Seo, Jun-Kyu;Kim, Kyung-Jo;Oh, Min-Cheol;Lee, Sang-Min;Kim, Young-Jae;Kim, Myung-Hyun
    • Korean Journal of Optics and Photonics
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    • v.19 no.1
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    • pp.68-72
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    • 2008
  • Fiber-optic strain sensors based on Bragg reflection gratings produce the change of reflection spectrum when an external stress is applied on the sensor. To measure the Bragg reflection wavelength in high speed, an arrayed waveguide grating device is incorporated in this work. By monitoring the output power from each channel of the AWG, the peak wavelength corresponding to the applied strain could be obtained. To enhance the accuracy of the AWG wavelength interrogation system, a chirped fiber Bragg grating with a 3-dB bandwith of 5.4 nm is utilized. The high-speed response of the proposed system is demonstrated by measuring a fast varying strain produced by the damped oscillation of a cantilever. An oscillation frequency of 17.8 Hz and a damping time constant of 0.96 second are obtained in this measurement.

Optimization of sterilization conditions for the production of retorted steamed egg using response surface methodology (반응표면분석을 이용한 레토르트 계란찜의 살균조건 최적화)

  • Cheigh, Chan-Ick;Mun, Ji-Hye;Chung, Myong-Soo
    • Korean Journal of Food Science and Technology
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    • v.50 no.3
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    • pp.331-338
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    • 2018
  • The purpose of this study was to determine the optimum sterilization conditions for the production of retorted steamed egg using response surface methodology. Sterilization processes for eighteen conditions using varying sterilization temperature ($X_1$), time ($X_2$), and method ($X_3$) as the independent variables were carried out through a $3^2{\times}2$ experimental factorial design. Quality evaluations after sterilization included measurements of $F_0$ value ($Y_1$), peak stress ($Y_2$), pH ($Y_3$), color value ($Y_{4-6}$), and organoleptic test [preference for appearance ($Y_7$), overall acceptability ($Y_8$), and preference for texture ($Y_9$) and egg taste ($Y_{10}$)]. Dependent variables ($Y_{1-10}$) of eighteen conditions were more affected by temperature and time than by the sterilization method. Eight factors were selected among the dependent variables as significant factors related to the quality of the steamed egg. Finally, by establishing an optimum range of each dependent variable and contour analysis, the optimum sterilization conditions for the production of steamed egg were determined to be $120^{\circ}C$ for 25 min using a 2-step sterilization process.

A Feasibility Study on the Use of Liner and Cover Materials Using Sewage Sludge (하수슬러지의 차수재 및 복토재로의 이용타당성에 관한 연구)

  • 유남재;김영길;박병수;정하익
    • Journal of the Korean Geotechnical Society
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    • v.15 no.2
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    • pp.43-71
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    • 1999
  • This research is an experimental work of developing a construction material using municipal wastewater sludge as liner and cover materials for waste disposal landfill. Weathered granite soil and flyash, produced as a by-product in the power plant, were used as the primary additives to improve geotechnical engineering properties of sludge. For secondary additives, bentonite and cement were mixed with sludge to decrease the permeability and to increase the shear strength, respectively. Various laboratory test required to evaluate the design criteria for liner and cover materials, were carried out by changing the mixing ratio of sludge with the additives. Basic soil properties such as specific gravity, grain size distribution, liquid and plastic limits were measured to analyze their effects on permeability, compaction, compressibility and shear strength properties of mixtures. Laboratory compaction tests were conducted to find the maximum dry densities and the optimum moisture contents of mixtures, and their effectiveness of compaction in field was consequently evaluated. Permeability tests of variable heads with compacted samples, and the stress-controlled consolidation tests with measuring permeabilities of samples during consolidation process were performed to obtain permeability, and to find the compressibility as well as consolidational coefficients of mixtures, respectively. To evaluate the long term stability of sludges, creep tests were also conducted in parallel with permeability tests of variable heads. On the other hand, for the compacted sludge decomposed for a month, permeability tests were carried out to investigate the effect of decomposition of organic matters in sludges on its permeability. Direct shear tests were performed to evaluate the shear strength parameters of mixed sludge with weathered granite, flyash and bentonite. For the mixture of sludge with cement, unconfined compression tests were carried out to find their strength with varying mixing ratio and curing time. On the other hand, CBR tests for compacted specimen were also conducted to evaluate the trafficability of mixtures. Various test results with mixtures were assessed to evaluate whether their properties meet the requirements as liner and cover materials in waste disposal landfill.

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