http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Remaining Strength Estimation Methods of Plate Girders with Corrosion and the Practical Evaluations
Naoyuki Asao,Katashi Fujii 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.1
In steel plate girder railway bridges with open deck system, damage caused by local corrosion of the upper flanges under sleepers is well-known. This damage reduces ultimate strength of the main girders significantly (e.g., in the case of 50%-corroded upper flanges, approximately 30 percent reduction in bending strength). This paper presented a simple evaluation method for estimating the remaining strength of the plate girders that have local corrosion damage under sleepers. Remaining strength of the damaged plate girders can be calculated by taking into account both the remaining strength for local load (hereinafter referred to as “patch load”) that acts directly on the upper flanges under the sleepers, and the remaining strength for bending load that acts on the main beam itself. This new evaluation method using the equations proposed in this paper, is based on the idea that the remaining strength under pure bending load can be obtained as the minimum value of strengths calculated in light of the various buckling modes of the compression flange, while taking the thickness reduction due to corrosion into account. Thereafter, the remaining strength under patch load only can be calculated by using an equation which is further simplified based on Takimoto’s original equation. Finally, the remaining strength of the plate girder as a whole is obtained from the strength interaction curve between patch and bending loads. In addition, by comparing the estimated remaining strengths obtained through this method with those obtained from nonlinear Finite Element Method (FEM) analyses using full-scale beam models, it could be concluded that the simple evaluation method by using both new and original equations can estimate the remaining strength of plate girders with corroded flanges under sleepers with around 95 percent accuracy.
Naoyuki Asao,Katashi Fujii 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.10
In Japan, many steel railway bridges were constructed during the period of rapid economic growth in the 1960s. Now, as over 50 years have passed, the condition of these aging structures has become conspicuous, and a major social problem. In particular, the deterioration and damage due to corrosion in steel plate girder railway bridges with open deck system is becoming pronounced. Nevertheless, the remaining strength evaluation and the methods of reinforcing corroded structures are not always sufficient. Therefore, the purpose of this study is to propose an analytically-based evaluation method, and a reliable measure of reinforcement in the field of steel railway bridge maintenance. The following is noted: 1) Regarding the shear capacity of plate girders with corrosion near supports, the remaining strength depends on the condition of the corroded surface of each component of the member, such as a web or a vertical stiffener. Also, according to the form and degree of corrosion, the fracture mode also changes from the buckling of web to the buckling of cross-shape columns which consisting of the web and vertical stiffener. The result shows that the corroded web has more effect on the shear capacity than the vertical stiffener. 2) Regarding situation of separation between the web and bottom flange due to corrosion near supports, the remaining strength is found to deteriorate more rapidly than in the Case 1 above when the separation area lengthens to more than that of the sole plate area. 3) To enhance the remaining shear capacity in the Cases 1 and 2 above, the load bearing capacity can be improved dramatically by unsophisticated attachments applied as reinforced members.
Preparation and Electric Double Layer Capacitance of Mesoporous Carbon
Soshi Shiraishi,Hideyuki Kurihara,Asao Oya 한국탄소학회 2001 Carbon Letters Vol.1 No.3
Mesoporous activated carbon fiber (ACF) was prepared from phenolic resin containing a small amount (0.1 wt %) of organic nickel complex through carbonization and steam activation. Microporous ACF as reference sample was also prepared from phenolic resin without agent. In both cases of the mesoporous ACFs and the microporous ACFs, the electric double layer capacitance of the nonaqueous electrolyte (0.5 M TEABF4/PC or 1.0 M LiClO4/PC) was not proportional to the BET specific surface area. This is owing to the low permeability of nonaqueous electrolyte or the low mobility of ion in narrow micropores. However, the mesoporous ACF showed higher double layer capacitance than the microporous (normal) ACF. This result suggests that the presence of many mesopores promotes the formation of effective double layer or the transfer of ion in the micropore.
( Kentaro Kotani ),( Hiroki Sato ),( Satoshi Suzuki ),( Takafumi Asao ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-
This study introduces a potential technique for Japanese kana characters on tactile information display device (tactile display) that allows the user effectively perceived. Currently tactile display has not been developed for the purpose of character information transmission due to poor performance of recognition rates in terms of characters. The purpose of this study is to evaluate a novel technique, flick motion based display, for presenting Japanese kana characters on the tactile display (FMR tactile display). Flick motion is normally used as an input scheme for mobile devices, as one of touch screen gestures. In Japan, a set of flick motions on 10 isolated areason the touch screen is especially assigned as Japanese kana character entry. Many Japanese mobile phone users have its mental model, which was applied to present character information as an output scheme into tactile display. Experiments were conducted to evaluate how the implemented presentation system can perform well to let the user perceive kana characters. A total of 10 subjects, including users unfamiliar to FMR, participated in the study. The subjects located their right hand on the tactile display and a kana character by using FMR was given on the display. They responded the characters as soon as they perceived.