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Yuki Y.,Yokogawa Bridge Holdings Corporation | Ikezue K.,Yokogawa Bridge Holdings Corporation | Kasugai T.,Yokogawa Bridge Holdings Corporation | Oshita S.,YCE Corporation
Proceedings of the 9th International Conference on Shock and Impact Loads on Structures | Year: 2011

This paper presents a new device to prevent bridges from collapsing and an impact load experimental methodology for such devices. A feature of the newly developed device is that the anchorage area of both ends of the cable has two-hinged connections. Therefore, the cable can rotate in the biaxial direction. This system simplifies the process of setting a new device for bridges. In addition, the device has a shock-absorbing rubber material surrounding the hinge pins. On the other hand, there is no unified experimental methodology that can measure the impact load of the device to prevent bridge falling-down. Therefore, the authors designed a suitable experimental methodology. Additionally, the impact performance, mainly related to absorbing performance, of the newly developed device is investigated using the experimental methods. As a result, it is first established that the performance of the developed falling-down preventing device is sufficient when compared to conventional devices. Secondly, it is confirmed that the developed impact experimental methodology can be applied to such a device. Source


Konda N.,Nippon Steel & Sumitomo Metal Corporation | Aromochi K.,Nippon Steel & Sumitomo Metal Corporation | Nishio M.,Nippon Steel & Sumitomo Metal Corporation | Ichimiya M.,Yokogawa Bridge Holdings Corporation | And 2 more authors.
Bridge Maintenance, Safety, Management, Resilience and Sustainability - Proceedings of the Sixth International Conference on Bridge Maintenance, Safety and Management | Year: 2012

Under heavy traffic conditions, some fatigue cracks have been found at welding joints between U-shaped ribs "trough ribs" and deck plates. Fatigue cracks along thickness direction of deck plate from root tip are important because visual crack detection from outside is limited. In this paper, new functional steel plates with initiation resistance of fatigue crack at weldment and propagation resistance at base material are applied to deck plate to evaluate improvement of fatigue life. We conducted fixed-point fatigue tests with real scale partial models consisted with one trough rib and a transverse girder, and the elastic FEM analysis corresponding to the fatigue test specimen. Based on these results, we studied the fatigue properties which focused on the difference between conventional steel plates and newly developed steel plates, FCA. Fatigue cracks were initiated from root tip of welded joints between a trough rib and a deck plate. It is clarified that FCA steel plates instead of conventional steel plates can improve the fatigue life under the same welding conditions. This improvement effect becomes much clearer in the high cycle region, which is noticeable at the operation and management stage of bridges. © 2012 Taylor & Francis Group. Source


Konda N.,Nippon Steel & Sumitomo Metal Corporation | Nishio M.,Nippon Steel & Sumitomo Metal Corporation | Ichimiya M.,Yokogawa Bridge Holdings Corporation | Kasugai T.,Yokogawa Bridge Holdings Corporation | Kiyokawa S.,Yokogawa Bridge Holdings Corporation
International Journal of Steel Structures | Year: 2013

Under heavy traffic conditions, some fatigue cracks have been found at welding joints between U-shaped ribs "trough ribs" and deck plates. Fatigue cracks along thickness direction of deck plate from root tip are important because visual crack detection from outside is limited. In this paper, new functional steel plates with initiation resistance of fatigue crack at weldment and propagation resistance at base material are applied to deck plate to evaluate improvement of fatigue life. We conducted fixed-point fatigue tests with real scale partial models consisted with one trough rib and a transverse girder, and the elastic FEM (Finite Element Method) analysis corresponding to the fatigue test specimen. Based on these results, we studied the fatigue properties which focused on the difference between conventional steel plates and newly developed steel plates, FCA (Fatigue Crack Arrester). Fatigue cracks were initiated from root tip of welded joints between a trough rib and a deck plate. It is clarified that FCA steel plates instead of conventional steel plates can improve the fatigue life under the same welding conditions. This improvement effect becomes much clearer in the high cycle region, which is noticeable at the operation and management stage of bridges. © 2013 Korean Society of Steel Construction and Springer-Verlag Berlin Heidelberg. Source


Uno M.,Kyushu University | Tamai H.,Kyushu University | Yuki Y.,Yokogawa Bridge Holdings Corporation | Sonoda Y.,Kyushu University | Kasugai T.,Yokogawa Bridge Holdings Corporation
10th International Conference on Shock and Impact Loads on Structures 2013 | Year: 2013

The Japanese Specification for Highway Bridges requires the installation of unseating prevention device on bridges identified as necessary. Recently, a new type of cable restrainer was developed, whose assembly allows the cable to rotate and creates no restriction to their brackets' mounting angle. Cylindrical rubbers are inserted around pins to absorb impact forces. However, no standard design method of the shock absorber has been established yet. This paper presents the study of the impact resisting characteristics of the pin-fixed cable device with a goal of developing the appropriate design method of the shock absorbing rubbers by conducting impact load tests on bracket models of the actual restrainers. As a result, it was observed that pin fixed restrainer has sufficient impact resistance and that there are some trends with maximum impact load. We have also conducted FE analyses on the device assuming the hyperelastic behaviour of three-parameter Mooney-Rivlin model. The analyses could nearly demonstrate the impact response trend obtained from the conducted experiments. Source


Kainuma S.,Kyushu University | Jeong Y.-S.,Kyushu University | Yang M.,Kyushu University | Inokuchi S.,Yokogawa Bridge Holdings Corporation
Measurement: Journal of the International Measurement Confederation | Year: 2016

Fatigue cracks have recently been observed at weld roots between the deck plate and U-rib in orthotropic steel decks. Some cracks initiated from the weld roots and then propagated through the deck plate. The welding residual stress at the root appears to have a considerable influence on crack initiation and propagation. However, the stress has not yet been efficiently clarified in previous studies. In this study, the residual stress of model specimens with or without weld penetration and root gap were measured using the cutting method and magnetostriction method. In addition, thermo-elastic-plastic finite element analyses were carried out on parametric models of actual welded joints. © 2016 Elsevier Ltd Source

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