http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Keiji Tajima (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Keiji Tajima,Hirokazu. Ishiguro,Toshihiko Aso 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.4
This paper describes a study on improving redundancy in a 240 m span steel Pratt truss bridge. Redundancy was evaluated from two perspectives. The fi rst perspective was how many members would induce bridge collapse owing to their own damage, and the second perspective was how many members would be damaged owing to another member’s damage. Members corresponding to these two perspectives were widely present throughout the subject truss bridge. As a measure to improve redundancy of the subject truss bridge, the method of installing alternative load paths by retrofi tting additional braces was studied. Three proposals with diff erent geometry of the additional braces were compared, and "X bracing", which equipped X-shaped braces by adding braces in the opposite direction to the existing diagonal member, demonstrated excellent performance. In addition, the eff ect of the method retrofi tting the cable along the member was also studied. Next, the placement patterns of "X bracing" on 18 truss panels of the subject truss bridge were examined using an optimization technique. It was clarifi ed that examination of the placement for the additional braces was important for the effi cient improvement of redundancy, and that the optimum placement of X bracing was in the alternating areas. Finally, the buckling gusset plate of the I-35 W bridge was also in the alternating area, suggesting that reinforcement of the alternating area might be important for redundancy of truss bridges.
-
Cao Vu Dung,Eiichi Sasaki,Keiji Tajima,Toshimitsu Suzuki 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.2
A common practice for the manufacture of orthotropic steel decks in Japan is to use 75% partial joint penetration welds between closed ribs and deck plates. To evaluate the effectiveness of the proposed 100% penetration on improving the fatigue strength of rib-to-deck welded joints in orthotropic steel bridge decks, four full-scale orthotropic deck specimens were subjected to laboratory testing. Specimens, consisting of a 12-mm-thick deck plate and 6-mm-thick rib, with one closed rib, were fabricated with 75% and 100% penetration. Fatigue test results showed that fatigue cracks initiated from the weld toe inside the rib in the 100% penetration specimens, but from weld root inside the rib in the 75% penetration specimens. To investigate this fatigue behavior, strain measurements were taken at 5 mm from the rib-to-deck weld line. Results of finite element analysis using the effective notch stress method indicate that a deeper partial penetration results in a slightly higher effective notch stress at the weld root of the partial penetration weld. The effective notch stress at the crack initiation location with 100% penetration is lower than that obtained with partial penetration. The open angle appears to have a significant effect on the effective notch stress at the upper weld toe when using 100% penetration. Therefore, the proposed 100% penetration appeared to have a positive effect on enhancing the fatigue resistance of rib-to-deck welded joints.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
