The purpose of this paper is to clarify a bending moment share of beam web in the flange welded - web bolted beam-to-column joint. Static cyclic loading tests (for two type specimens of full scale beam-to-column joint) were carried out. One is the flange welded-web bolted joint (specimen F) and the other is the web bolted joint only (specimen NF). The flange fracture occurred in case of specimen F and the shear fracture of bolt occurred in case of specimen NF. The bending moment share of bolted joint web was make clear by comparing the load-deflection relationships of the two specimens.

View full abstract

Penetration depth of single-sided fillet weld between a trapezoidal rib and a deck plate in a steel plate deck is specified over 75% of the trapezoidal rib thickness in the Japanese Specifications for Design of Steel Highway Bridges in order to avoid fatigue problem. However, an effect of the weld penetration on the fatigue strength of single-sided fillet welded joint has not been made clear. In this study, the influence of the weld penetration depth on the fatigue strength is examined through fatigue tests, FEM stress analyses and fatigue crack propagation analyses.

View full abstract

For a more economical design, for the controlling of stiffness and for esthetic considerations, the haunched beams are frequently used. This paper is described and evaluated the flame cutting and the bending of the bottom flange in the actual shop fabrication. The bending tests were conducted on the flange plate cutting off the rolled-H section member. The bending properties of the flange plate under room temperature are examined. The occurrence of cracking on the plate bending and the level of plastic bending are found at the intersection of the haunch and the rolled-H section member.

View full abstract

Seismic behavior of steel members will be strongly influenced by the difference of material properties. To investigate the effects of material property and the shape of the H-section on the rotation capacity of beam-to-column connections, a detailed finite element analysis are used in this study. In case of considering a ductile crack at the beam-to-column connections, it is important to take into account both width thickness ratio and the ratio of plastic section modulus of web on H-beam (Zwp/Zp). The regions of width thickness ratios whose rotation capacity of beam-to-column connections is not defined by the strength degradation but by the initiation of ductile crack are indicated in this paper.

View full abstract

This paper deals with an experimental study on the interactive buckling behavior of steel compression members with thin-walled stiffened box cross section. In this study, attention is paid to the interactive behavior of local plate buckling and global column buckling, the ultimate strength, and the ductility of the steel compression members. The local plate buckling consists of the buckling of component stiffened plate panels, local plate panels between longitudinal stiffeners, and longitudinal stiffeners. Axial loading tests are carried out for the scaled down column specimens with variouswide-thickness ratio of the plate panels and the slenderness ratio as columns to investigate the interactive behavior. Indices for deciding the occurrence of the bucklings are proposed by using various strain data at the middle cross sections of the specimens and the buckling phenomena of the specimens are investigated regarding the global buckling, the local plate buckling and their interactive buckling by using the indices. Effectiveness of these indices is discussed here in.

View full abstract

This investigation is carried out to clear the difference of lateral stiffness of rahmen frame due to various methods for elastic rotation stiffness of steel exposed-type column base . At first, a new formula for elastic rotation stiffness of steel exposed-type column base considered column axial force and concrere stiffness under base-plate is suggested. It is compared and discussed that lateral stiffness of rahmen frame by nonlinear elastic analysis using the suggested formula compared with the result by conventional elastic analysis using the formula by Architectural Institute of Japan.

View full abstract

The effectiveness of energy absorbing connecters is investigated for steel continuous girder supported by rubber bearings. Steel bellows as energy absorbing devices are connected between girders in a row. The influence of boundary conditions is examined using two models of five and seven segments in which a continuous steel girder is treated as one segment. The periods of each segment are changed in various kinds by combining several rubber bearings and each case is examined. Yield strengths of steel bellows are so decided as to avoid the collision between girders. The effectiveness of steel bellows as energy absorbing connectors is confirmed by non-linear time-history analyses.

View full abstract

This paper discusses three subjects for long span gable trussed structures based on the results of elasto-plastic earthquake response analyses. First, the strength and deformation capacity of the gable trussed structures designed by the static earthquake loads proposed in the previous paper is examined. Then, a set of hysteresis dampers installed at the feet of the columns are proven to be much effective for increasing earthquake resistant capacity. Finally, a method for designing the dampers is investigated by the energy concept.

View full abstract

Recently, a composite girder with steel girder and concrete slab is reconsidered. However, cracks of concrete slab in the negative moment region over the internal support of the continuous composite girder are a serious subject. This paper dealswith the comparison between an inelastic behavior of the two-span continuous composite girder specimens and the one obtained from the rigid-body-spring model analysis. The comparison describes that the rigid-body-spring model analysis employed can relatively well simulate the inelastic behavior of the continuous composite girder and crack width of the concrete slab up to its ultimate state.

View full abstract