Bolted connections for non-intersecting H-section beam and column in steel moment frames

This research proposes connection configurations of two types for non-intersecting H-section steel beam and column. To elucidate the mechanical behavior of the proposed connections, full-scale moment connection tests and finite element analyses were conducted using T-shaped partial frame models. Comparisons between the proposed connections and regular intersecting connections demonstrate that the proposed connection is able to provide sufficient stiffness and energy-dissipation capacity if the beam and column flanges are designed to provide sufficient shear resistance. Then to understand the global behavior of frames using the proposed connections, pushover analyses of a two-story two-span frame were conducted. Because the bending moment of the beam acts on the column by a torque through the proposed connections, torsion spring models were incorporated for representing the proposed connections in 3D frame analysis. Analysis results showed that the girders and columns exhibited lower stiffness and strength than those of frames with intersecting connections because of torsion. To overcome this issue, torsion restraint by secondary beams with different configurations was discussed and optimal configuration was suggested. By utilizing the optimal configuration, torsion of girders and columns can be efficiently reduced into a similar level as that of regular intersecting connections

テンネン センイ デ キョウカ シタ キノウセイ グリーン コンポジット ノ カイハツ

Various types of unidirectional and random bamboo fiber reinforced “green” composites were fabricated, and examined their damping properties as a function of fiber content. The loss factors decreased with increasing fiber content. However they decreased gently higher than 40mass percent fiber content, the tensile modulus increased proportionally to the fiber content of about 80mass percent. The definite relationship between loss factor and Young’s modulus was not found. In addition, loss factors of random fiber (10mm fiber) reinforced “green” composites are larger than loss those unidirectional (continuous fiber) ones

Risk for Tuberculosis among Children

Risk among children is underestimated in countries with a high incidence of this disease

Open Access

Cost-effective length and timing of school closure during an influenza pandemic depend on the severit

Impact and recovery of an intertidal ecosystem from the Nakhodka heavy- oil spill

鹿児島大学神戸大学東京大学千葉大学Editor : Tazaki, Kazue |田崎, 和

Orthodontic Management of the Edentulous Space Caused by Surgical Removal of a Large Dentigerous Cyst

Herein, we report the orthodontic management of a patient with excessive bone and permanent tooth loss after surgical cyst removal. The patient was a 13-year-old Japanese boy who was referred to our department by an oral surgeon. He had an edentulous space with alveolar bone loss and loss of 2 permanent molars in the left mandibular region, following surgical removal of a large dentigerous cyst. We decided to close this space orthodontically. First, we moved the left mandibular second premolar into the edentulous region and autotransplanted the left maxillary lateral incisor in the adjacent distal space. We then performed comprehensive orthodontic treatment to establish stable occlusion. Following treatment, functional and stable occlusion of all permanent teeth was achieved without any spaces. The findings from this case suggest that orthodontic treatment is effective in growing patients with edentulous spaces and alveolar bone loss