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Strength and stiffness of panel and joint in non-diaphragm CHS-column to H-beam connection were experimentally investigated Herein, the panel means the cylindrical stub circumscribed by outer planes of the beam and the column, and the joint means the butt seam between the column wall and the beam end. Two types of specimen were tested: one is an X-shaped frame whose panel is subjected to shear, and the other is a 3-point bending specimen whose panel is free from shear. In result, the joint strength and stiffness are well predicted by the previously proposed formulae irrespective of the existence of shear in the panel, and the panel strength and stiffness are also well predicted by the well known formulae given for diaphragm connections. This suggests that the interaction between panel and joint of the non-diaphragm connection can be ignored in structural design. Japan Society for the Promotion of Science, JSPS: 15J10631

A moment frame with bracing elements is one of efficient seismic-resistant structural system in elastic design, however, when the seismic input is larger than the buckling strength of braces, these undergo local buckling subsequent to overall buckling, and the concentration of plastic strain at local buckling area easily leads to brace fracture. The authors have previously proposed a brace fracture prediction method. In this paper, time-history response analyses for braced frames are carried out focusing on the brace fracture using the proposed method. A discussion follows fatigue distribution in the frame types, including the effect of the brace fracture itself.

Structural system composed of high-strength steel frame with energy-dissipation elements is one of the suitable solutions for damage tolerant structure. In this concept, the main structure is designed in elastic zone for design earthquake level; however, there are still some risks to step into plastic zone in maximum considered earthquake levels. Because of high strength steel having high yield ratio, it is concerned to fracture early after yielding. In this paper, following the mock-up cyclic-loading tests and analysis of 800Mpa steel beam-column frame with diagonal BRBs, their fracture mechanism of beam-end connections are modeled using simple non-linear rotation springs, and estimation method for their cumulative energy dissipation capacities until their fractures in multistory structures are proposed.

A Buckling Restrained Brace (BRB) with serially connected tubular members is one of the solutions for composing BRB over 10m length economically for the seismic design of truss structures or large-span structures. Their overall buckling condition is considered to be sensitive for imperfections or eccentricities comparing to ordinary BRBs; however, their effects are not confirmed by experiments yet. In this paper, the overall buckling conditions for BRBs with serially connected tubular members are discussed as the functions of imperfections or eccentricities. Their effects on the stability are confirmed by cyclic loading experiments until member fractures, and design criteria are proposed.

The post-buckling hysteresis model for the braces under cyclic axial force proposed by M.Wakabayashi, M.Shibata and others are popularly used for time-history analyses for braced frames. Also the authors have proposed easy evaluation method predicting the fracture point of the braces after local buckling. However, these methods are derived from pin-ends boundary conditions, and performances under rigid or semi-rigid conditions are not made clear yet. In this paper, detailed FEM analyses of H-section braces under various rigidity conditions are carried out, and parameters for post-buckling hysteresis model are identified. Also prediction method of fracture points for braces under various boundary conditions is proposed.

Buckling Restrained Braces (BRBs) are commonly used as ductile bracing elements in seismic design. A key limit of BRB is overall flexural buckling. However, their effective buckling lengths are affected by the stiffness and strength of their connection zones. In this paper, each connection zone is modeled as two rotational elastic springs at gusset plate and two rotational elasto-plastic springs at the end zone of the restrainer. Their stiffness and strength are investigated by mock-up experiments and analyses, and their evaluation methods are proposed.

H-section braces are widely used for seismic-proof elements in various kinds of structures. However, when they receive the cyclic loading beyond the expected seismic loads, they cause not only overall-buckling, but local buckling. It is known that such local buckling cause stress concentration within limited zones, and easily lead to the fracture of the member itself. Various hysteretic loop models for such braces have been proposed and used for timehistory analysis, however, it is not easy to predict the point of the fracture, their cumulative deformation capacity and energy dissipation capacity until the fracture. In this paper, cyclic loading tests on various H-section braces are carried out, and their fracture mechanism, relationship between the slenderness ratios and width-thickness ratios are researched. Their strain concentration mechanism is discussed through various analyses, followed by proposing easy evaluation method of their cumulative deformation capacity.

Buckling Restrained Braces (BRBs) are commonly used as ductile bracing elements in seismic lateral resistance systems. A key limit state governing BRB behavior is overall flexural buckling. However, when the wall thickness of the restrainer is relatively small compared to the core plates section, the restraint conditions against local buckling of the core plate about its strong axis can be critical for the stability and strength of the BRB. In this study, cyclically-loaded experiments and numerical analyses were carried out using various tube restrainer configurations, and the local buckling restraint conditions are discussed and proposed using these results.

The dynamic scheduling management system architecture that is based on the parts and information packets unified technology is developed, and variable lot size production with the parts and packets unified technology is proposed. We assumed that each part or unit has a data career, which handle such as identification number, position of the part, state of the part. Using these data, progress of the project process is compared with the master schedule. If the difference arises between them, scheduling system dynamically re-schedules with dynamic lot size to optimize the processes. A pilot system that realized our proposal is developed.

Fracture of concentric braced frames due to local buckling under cyclic loading often requires computationally intensive 3D shell models. For practical design, the authors have previously proposed a phenomenological stick model that accurately captures local fracture, referred to as the Direct Local Strain Evaluation Method. However, the accuracy of the proposed method has previously only been validated using quasi-static cyclic component tests. This research extends this work, validating the method under dynamic loading conditions using numerical studies and in-frame shake table testing. The method is shown to be in good agreement with the global response and to accurately capture fracture due to local buckling under cyclic dynamic loads.