• Structural Engineering and Mechanics
• /
• v.39 no.2
• /
• pp.267-285
• /
• 2011

There can be a significant amount of moment redistribution in composite frames consisting of steel columns and composite beams, due to cracking, creep and shrinkage of concrete. Considerable amount of computational effort is required for taking into account these effects for large composite frames. A methodology has been presented in this paper for taking into account these effects. In the methodology that has been demonstrated for moderately high frames, neural network models are developed for rapid prediction of the inelastic moments (typically for 20 years, considering instantaneous cracking, and time effects, i.e., creep and shrinkage, in concrete) at a joint in a frame from the elastic moments (neglecting instantaneous cracking and time effects). The proposed models predict the inelastic moment ratios (ratio of elastic moment to inelastic moment) using eleven input parameters for interior joints and seven input parameters for exterior joints. The training and testing data sets are generated using a hybrid procedure developed by the authors. The neural network models have been validated for frames of different number of spans and storeys. The models drastically reduce the computational effort and predict the inelastic moments, with reasonable accuracy for practical purposes, from the elastic moments, that can be obtained from any of the readily available software.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.6 no.3
• /
• pp.723-736
• /
• 2014

Glass Fiber Reinforced Plastic (GFRP) structures are primarily manufactured using hand lay-up or vacuum infusion techniques, which are cost-effective for the construction of marine vessels. This paper aims to investigate the mechanical properties and failure mechanisms of the hybrid GFRP composites, formed by applying the hand lay-up processed exterior and the vacuum infusion processed interior layups, providing benefits for structural performance and ease of manufacturing. The hybrid GFRP composites contain one, two, and three vacuum infusion processed layer sets with consistent sets of hand lay-up processed layers. Mechanical properties assessed in this study include tensile, compressive and in-plane shear properties. Hybrid composites with three sets of vacuum infusion layers showed the highest tensile mechanical properties while those with two sets had the highest mechanical properties in compression. The batch homogeneity, for the GFRP fabrication processes, is evaluated using the experimentally obtained mechanical properties.

• Structural Engineering and Mechanics
• /
• v.84 no.6
• /
• pp.767-782
• /
• 2022

In this paper, the nonlinear vibration behavior of the spiral stiffened multilayer functionally graded (SSMFG) cylindrical shells exposed to the thermal environment and a uniformly distributed harmonic loading using a semi-analytical method is investigated. The cylindrical shell is surrounded by a nonlinear viscoelastic foundation consisting of a two-parameter Winkler-Pasternak foundation augmented by a Kelvin-Voigt viscoelastic model with a nonlinear cubic stiffness. The distribution of temperature and material constitutive of the stiffeners are continuously changed through the thickness direction. The cylindrical shell has three layers consisting of metal, FGM, and ceramic. The interior layer of the cylindrical shell is rich in metal, while the exterior layer is rich in ceramic, and the FG material is located between two layers. The nonlinear vibration problem utilizing the smeared stiffeners technique, the von Kármán equations, and the Galerkin method has been solved. The multiple scales method is utilized to examine the nonlinear vibration behavior of SSMFG cylindrical shells. The considered resonant case is 1:3:9 internal resonance and subharmonic resonance of order 1/3. The influences of different material and geometrical parameters on the vibration behavior of SSMFG cylindrical shells are examined. The results show that the angles of stiffeners, temperature, and elastic foundation parameters have a strong effect on the vibration behaviors of the SSMFG cylindrical shells.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.1
• /
• pp.17-25
• /
• 2020

In this study, non-flammable mineral foam board using waste glass that can be produced to standardized specifications were developed and evaluated for the performance. In addition to the physical and mechanical performance, the environmental properties such as insulation, non-combustibility, gas hazard, sound absorption, etc. were tested to verify the use as interior and exterior building materials. Through the structural review, the validity was verified for the application of the office and restaurant building.

• KIEAE Journal
• /
• v.15 no.1
• /
• pp.111-116
• /
• 2015

Heat loss from windows and condensation occuring on its surface due to its lower insulation value causes much discomfort to occupants. In this study, Heated glass was used to make a basic study on prevention of condensation on glass surface for its heating functionality through experimental measurement and simulation analysis of total heat flux on the interior and exterior surface of glass. Error between experimental results and three dimensional steady-state heat transfer analysis were caused firstly, beacuse in the experimental chambers, cold chamber and steady temperature and humidity chamber, air temperature setting was not constant but rather ON/OFF control, and secondly, due to error rate in heat flux meter due to heat flux direction even in stable conditions.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.2 no.3
• /
• pp.146-154
• /
• 2010

In the present study, the wave excitation forces acting on an array of porous circular cylinders are examined based on diffraction problems. To calculate the wave forces, the fluid domain is divided into three regions i.e. a single exterior region, N interior regions and N beneath regions, and the diffraction in each fluid region is expressed by an eigenfunction expansion method with using 3-dimension liner potential theory (Williams and Li, 2000). Especially, the present method is extended to the case of an array of truncated porous circular cylinders to calculate the heave forces as well as surge and sway forces. To verify this method, the numerical results obtained by eigenfunction are compared with these results obtained by higher order boundary element method (Choi et al., 2000). The numerical results obtained by this study are in good agreement with those results. By changing the numbers of porous circular cylinders, the angle of incident wave and the porosity rate of circular cylinders, the wave excitation forces such as surge, sway and heave on an array of truncated porous circular cylinders are investigated.

• Journal of the Korean Society for Railway
• /
• v.8 no.4
• /
• pp.354-360
• /
• 2005

The railway track and the substructures constructed in the field test section of Kyongbu High Speed Line are the structures for HSL, for the first time designed and constructed by domestic technical group. It is very important to verify the local design criteria and specifications for these structures and also to assure the recordings for vibration or deflection produced on the essential parts of the structures. The study to verify the high-speed railway track performance and to ensure the run in safety on the track in curved section during the KTX run. Finally, the conclusion are drawn as follows. The measuring values of the deflection effort of the rail and displacement for verifying the track performance in the field test section of Kyoungbu HSL satisfy the criteria of the foreign countries (Japan and Germany). The measured value for the wheel load and the presumed value show the consistent tendency. The wheel loads of the exterior and interior of the rails at the speed superior to 300km/h are measured same. Finally, the comparison between the theoretical value presented during the verification of the derailment to evaluate the safety of the train run at the time of the detailed design of the track and the measured value in the field shows that the correct design of track structure was applied.

• Journal of Korean Medical classics
• /
• v.30 no.2
• /
• pp.99-112
• /
• 2017

Objectives : 28 prescriptions with the name 'Dossi' can be found in Yixuerumen, and all these prescriptions are highly useful due to their clinical effectiveness. Among them, Dossisosihotang has an important role as the essential prescription utilizing harmonizing and releasing formula. Therefore, this paper aims to ponder upon this prescription. Methods : Dossisosihotang's origin and effectiveness were studied, and the findings served as the basis for analyzing the varied forms of this prescription which came about in the later generations in order to consider more detailed usage of this prescription. Results & Conclusions : Dossisosihotang directs its patient to consume sosihotang added with chenpi, shaoyao, chuanxiong, then simmered, and added with three spoons worth of raw wormwood juice. Its origin can be traced back to shachechuifa's 'Sihossanghaeeum,' and it is mainly effective for treating the blood aspect syndrome of lesser yang disease such as women's cold damage and heat entering the blood chamber. In treating the symptom of half-exterior and half-interior, taohua developed prescriptions depending on the syndrome, such as Sihijigyungtang, Sihohamhyoungtang, Samhosambacktang, Siryungtang, Sihosamultang, Sigalhaegitang, and Samhoseoggotang. These prescriptions became widely known for their clinical efficacy, leading to many later generations of clinical doctors to use them.

• Journal of architectural history
• /
• v.23 no.3
• /
• pp.43-54
• /
• 2014

Naejeon area at Chandeokgung Palace means the areas of Huijeongdang and Daejojeon area. Huijeongdang or Hall of Brilliant Rule is made for the king, and Daejojeon or Hall of Great Creation is made for the queen. These areas were located nearly and repeatedly burned down and rebuilt several times together, but their forms were largely unchanged. However in 1920, they rebuilt in a very different way. The purpose of this study was to estimate construction plans, progress and completion of Naejeon area's rebuilding. They were reconstructed into eclectic structures as the exteriors were built using basic materials from Gyeongbokgung Palace. So they have traditional-looking appearances, but the interiors consisted of modern equipments and were built by applying foreign style construction techniques. The main floored room of Daejojeon and the area of Huijeongdang were built in standing style by installing radiators and French furnitures. Also, the porch, corridor, storage space and veranda were constructed under the influence of Japanese construction. After the reconstruction, there were changes in the usage of some spaces. Huijeongdang functioned only for Alhyeonso or audience chamber rather than Pyeonjeon or state hall. New organizations created by the Japanese such as Chansi or secretaries office and the Chief secretary's office were included in Naejeon area.

• International Journal of Human Ecology
• /
• v.13 no.1
• /
• pp.147-157
• /
• 2012

The construction of government-sponsored housing in Korea began in the early 1950s. Beyond fulfilling the housing shortage after the Korean War, it also impacted the development of housing in Korea. The aim of this study is to explore the construction and supply of government-sponsored housing and to discuss the positive and negative influences on the modern housing in Korea. In order to achieve the objectives, the pictures and floor plans, newspaper articles and the KNHC publications, which led the public housing supply from 1950 to 1960, were examined. Results indicate as follows: First, government-sponsored housing industrialized the housing production, which satisfied the volume need. The simplified floor plan and exterior, along with the western characteristics, created a new urban landscape. Second, the distinct characteristics of Korean housing were established. By emphasizing development and financial practicality, large scale housing complexes were built with simplified, characterless, and mechanical exteriors in a disconnected territory with neighbor district. Third, government-sponsored housing became the major accelerator to westernize the Korean housing culture. In conclusion, the principles of functionalism of government-sponsored housing have become the fundamental root of Korean housing since the war.