• Structural Engineering and Mechanics
• /
• v.57 no.4
• /
• pp.681-701
• /
• 2016

This paper presents an experimental study of six steel reinforced high strength concrete T-shaped short-limb shear walls configured with T-shaped steel truss under low cyclic reversed loading. Considering different categories of ratios of wall limb height to thickness, shear/span ratios, axial compression ratios and stirrup reinforcement ratios were selected to investigate the seismic behavior (strength, stiffness, energy dissipation capacity, ductility and deformation characteristics) of all the specimens. Two different failure modes were observed during the tests, including the flexural-shear failure for specimens with large shear/span ratio and the shear-diagonal compressive failure for specimens with small shear/span ratio. On the basis of requirement of Chinese seismic code, the deformation performance for all the specimens could not meet the level of 'three' fortification goals. Recommendations for improving the structural deformation capacity of T-shaped steel reinforced high strength concrete short-limb shear wall were proposed. Based on the experimental observations, the mechanical analysis models for concrete cracking strength and shear strength were derived using the equivalence principle and superposition theory, respectively. As a result, the proposed method in this paper was verified by the test results, and the experimental results agreed well with the proposed model.

• Wind and Structures
• /
• v.18 no.6
• /
• pp.633-650
• /
• 2014

The uncertainty of extreme wind speeds is one key contributor to the uncertainty of wind loads and their effects on structures. The probability distribution of annual extreme wind speeds may be characterized using a classical Gumbel Type distribution. The expression that establishes the relationship between the extreme wind speeds at different recurrence periods and the corresponding coefficients of variation is formulated, and its efficacy is validated. The coefficients of variation are calibrated to be about 0.125 and 0.184 according to defined Chinese and US design specifications, respectively. Based on the wind data of 54 cities in China, 49 meteorological stations in the US, 3 stations in Singapore, the coefficients span intervals of (0.1, 0.35), (0.08, 0.20) and (0.06, 0.14), respectively. For hurricanes in the US, the coefficients range approximately from 0.3 to 0.4. This convenient technique is recommended as one alternative tool for coefficient of variation analyses in the future revisions of related codes. The sensitivities of coefficients of variation for 49 meteorological stations in the US are quantified and demonstrated. Some contradictions and incompatibilities can be clearly detected and illustrated by comparing the coefficients of variation obtained with different combinations of recurrence period wind data.

• Wind and Structures
• /
• v.18 no.1
• /
• pp.83-101
• /
• 2014

Lamps installed on stay cables of cable-stayed bridges may alter the configuration of circular cross section of the cables and therefore result in aerodynamically unstable cable vibrations. The background of this study is a preliminary design of lamp installation on the cable-stayed He-dong Bridge in Guangzhou, China. Force measurements and dynamic response measurements wind tunnel tests were carried out to validate the possibility of cable galloping vibrations. It is observed that galloping will occur and the critical wind velocity is far less than the design wind velocity at Guangzhou City stipulated in Chinese Code. Numerical simulations utilizing software ANSYS CFX were subsequently performed and almost the same results as the wind tunnel tests were obtained. Moreover, the pressure and velocity contours around cable-lamp model obtained from numerical simulations indicated that the upstream steel wire in the preliminary design is the key factor for the onset of the galloping vibrations. A modification for the preliminary design of lamp installation, which suggests to remove the two parallel steel wires, is proposed, and it effectiveness is validated in further wind tunnel tests.

• Journal of the Korean Society for Library and Information Science
• /
• v.8
• /
• pp.3-72
• /
• 1981

The necessity of computerizing the Central National Library of Korea has been widely recognized. The purpose of this research is to develop Korean Machine Readable Cataloging system as a first step toward an integrated library system and suggests the ways of utilizing the MARC file in Korean libraries as well as in the Central National Library. In this paper the following studies are included: 1. An analysis of the functions and current procedures of the Central National Library 2. Development of a standard record format for KOR MARC 3. Production and utilization of KOR MARC files 4. Identification of problems in developing KOR MARC system In conclusion, the following recommendations are made: 1. Standardization of the internal code and input/output equipments should be proceded for hangul and chinese data processing. 2. The libraries planning or having accomplished computerization process should be cooperative in standardizing and distributing bibliographic data bases including KOR MARC tapes. 3. Training of competent librarians and strong support from the government are required for a successful implementation of the Library's computerization project.

• Earthquakes and Structures
• /
• v.17 no.1
• /
• pp.39-48
• /
• 2019

This paper presents an experimental study on a 1/2 scale steel frame with archaized-style under the pseudo-dynamic loading. Four seismic waves, including El Centro wave, Taft wave, Lanzhou wave and Wenchuan wave, were input during the test. The hysteresis characteristic, energy dissipation acceleration response, displacement response, strength, stiffness and strain were analyzed. Based on the experiment, the elastoplastic dynamic time-history analysis was carried out with the software ABAQUS. The stress distribution and failure mode were obtained. The results indicate that the steel frame with archaized-style was in elastic stage when the peak acceleration of input wave was no more than 400 gal. Under Wenchuan wave with peak acceleration of 620 gal, the steel frame enters into the elastoplastic stage, the maximum inter-story drift was 1/203 and the bearing capacity still tended to increase. During the loading process, Dou-Gong yielded first and played the role of the first seismic fortification line, and then beam ends and column bottom ends yielded in turn. The steel frame with archaized-style has good seismic performance and meets the seismic design requirement of Chinese code.

• Structural Engineering and Mechanics
• /
• v.72 no.3
• /
• pp.313-327
• /
• 2019

Damage evolution in the form of void nucleation, propagation and coalescence is the primary cause that is responsible for the ductile failure of microalloyed steels. The Gurson-Tvergaard-Needleman (GTN) damage model has proven to be extremely robust for characterizing the microscopic damage behavior of ductile metals. Nonetheless, successful applications of the model on a given metal type are limited by the correct identification of damage parameters as well as the validation of the calculated void growth rate. The purpose of this study is two-fold. First, we aim to identify the damage parameters of the GTN model for Q345 steel (Chinese code), due to its extensive application in mechanical and civil industries in China. The identification of damage parameters is facilitated by the well-suited response surface methodology, followed by a complete analysis of variance for evaluating the statistical significance of the identified model. Second, taking notched Q345 cylinders as an example, finite element simulations implemented with the identified GTN model are performed in order to analyze their microscopic damage behavior. In particular, the void growth rate predicted from the simulations is successfully correlated with experimentally measured acoustic emissions. The quantitative correlation suggests that during the yielding stage the void growth rate increases linearly with the acoustic emissions, while in the strain-hardening and softening period the dependence becomes an exponential function. The combined experimental and finite element approach provides a means for validating simulated void growth rate against experimental measurements of acoustic emissions in microalloyed steels.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.34 no.6
• /
• pp.77-84
• /
• 2018

China has been pursuing continuous education reforms in order to complement the shortcomings of traditional education and to prepare for a new era in accordance with the development of the economy and society. School facilities were rapidly increased due to rapid population growth in the 60s and 70s, but the quality of the school facilities was low considering the efficiency and economy, and the regional variation was serious. The National Standard for School Design was enacted in 1986. Since then, we have proposed a new national standard in 2011 in accordance with social change and educational needs, and it has reached the present time. The purpose of this study is to analyze the main contents of "Code for design of school(GB50099-2011)" which is a standard study for Chinese school design as a basic study to understand changes in school architecture in China.

• Steel and Composite Structures
• /
• v.38 no.4
• /
• pp.381-397
• /
• 2021

Based on the spatial substructure hybrid simulation test (SHST) method, the seismic performance of a high-strength steel composite K-eccentrically braced frame (K-HSS-EBF) structure system is studied. First, on the basis of the existing pseudostatic experiments, a numerical model corresponding to the experimental model was established using OpenSees, which mainly simulated the shear effect of the shear links. A three-story and five-span spatial K-HSS-EBF was taken as the prototype, and SHST was performed with a half-scale SHST model. According to the test results, the validity of the SHST model was verified, and the main seismic performance indexes of the experimental substructure under different seismic waves were studied. The results show that the hybrid simulation results are basically consistent with the numerical simulation results of the global structure. The deformation of each story is mainly concentrated in the web of the shear link owing to shear deformation. The maximum interstory drifts of the model structure during Strength Level Earthquake (SLE) and Maximum Considered Earthquake (MCE) meet the demands of interstory limitations in the Chinese seismic design code of buildings. In conclusion, the seismic response characteristics of the K-HSS-EBFs are successfully simulated using the spatial SHST, which shows that the K-HSS-EBFs have good seismic performance.

• Steel and Composite Structures
• /
• v.43 no.6
• /
• pp.773-784
• /
• 2022

This paper aims to investigate the axial compressive behavior of reinforced concrete (RC) columns strengthened with self-compacting and micro-expanding (SM) concrete-filled steel tubes (SM-CFSTs). Nine specimens were tested in total under the local axial compression. The test parameters included steel tube thickness, filling concrete strength, filling concrete type and initial axial preloading. The test results demonstrated that the initial stiffness, ultimate bearing capacity and ductility of original RC columns were improved after being strengthened by SM-CFSTs. The ultimate bearing capacity of the SM-CFST strengthened RC columns was significantly enhanced with the increase of steel tube thickness. The initial stiffness and ultimate bearing capacity of the SM-CFST strengthened RC columns were slightly enhanced with the increase of filling concrete strength. However, the effect of filling concrete type and initial axial preloading of the SM-CFST strengthened RC columns were negligible. Three equations for predicting the ultimate bearing capacity of the SM-CFST strengthened RC columns were compared, and the modified equation based on Chinese code (GB 50936-2014) was more precise.

• Nuclear Engineering and Technology
• /
• v.55 no.1
• /
• pp.215-221
• /
• 2023

Proton treatment may deliver a larger dose to a patient's skin than traditional photon therapy, especially when a range shifter (RS) is inserted in the beam path. This study investigated the effects of an RS on skin dose while considering RS with different thicknesses, airgaps and materials. First, the physical model of the scanning nozzle with RS was established in the TOol for PArticle Simulation (TOPAS) code, and the effects of the RS on the skin dose were studied. Second, the variations in the skin dose and isocenter beam size were examined by reducing the air gap. Finally, the effects of different RS materials, such as polymethylmethacrylate (PMMA), Lexan, polyethylene and polystyrene, on the skin dose were analysed. The results demonstrated that the current RS design had a negligible effect on the skin dose, whereas the RS significantly impacted the isocenter beam size. The skin dose was increased considerably when the RS was placed close to the phantom. Moreover, the magnitude of the increase was related to the thickness of the inserted RS. Meanwhile, the results also revealed that the secondary proton primarily contributed to the increased skin dose.