Hideki Uesugi

Thermal Stress And Deformation Of Steel Structures Of High Rise Buildings In Fire

In analyzing thermal stresses and deformation of a high rise steel structure, exposed to a compartment fire, it is convenient to divide the structure into (a) the local substructure, directly fire exposed, (b) the adjacent substructure, the nearest floors and spans around the fire compartment, and (c the remalnlng part of the structure. For sUbstructure (a), the deformation behavior is normally elasto-plastic, for sUbstructure (b) purely elastic. For the remaining part (c),the fire induced stresses and deformations are generally negligible. This paper presents a method for the calculation of the stress and deformation behaviour of a high rise steel structure, exposed to a compartment fire, based on a subdivision of the structure as above. In order to illustrate the structural fire behaviour, 48 bUildings have been analysed according to the method presented.

Analyses Of Composite Beams And Frames At Elevated Temperature

This paper presents analyses of composite beam which is composed of H-section steel and reinforced concrete slab. Analyzed models were simply supported beams and H-shaped structural frames which were composed of 2-story columns and l-span beam. In analyzing simply supported beams, some other factors (for example, thickness of fire protection, width of slab etc...) were considered. In analyzing H-shaped structural frames, two models were considered. One model has composite beam, and the other model has H-section steel beam only. From the results of these analyses, it is concluded that the fire resistance of the structural frame with H-section steel beam and the structural frame with composite beam is almost the same.

Load-bearing Capacity of H-shaped Steel Columns under Local Buckling at Elevated Temperature

When a compartment fire occurs in a building of steel structure, large bending deformations are produced at the ends of columns and beams, inducing local buckling at these points. In this study, the load-bearing capacity of H-shaped steel columns under local buckling is clarified from pure compression tests and bending compression tests at constant temperatures ranging from room temperature to 600°C. On the basis of the tests, we propose, in relation to the fire resistance of H-shape steel stub columns, a relation between safety usable steel temperature and constant axial load ratio.

Study on Bending Strength of Web-Bolted Moment Joints of Aluminum Alloy Beam Exposed to Fire

This study narrows the application temperature field of aluminum alloy to 350 °C or less, and examines the strength of web-bolted moment joints within that temperature range. Bending strength of web-bolted moment joints of aluminum alloy exposed to fire is investigated experimentally and analytically. It is observed that if splice plate length and the beam section are designed appropriately, it is possible that maximum bending strength is fully realized with the web-bolted moment joints. The transmission mechanism of the bending moments is thought to be based on prying action between the flanges and splice plate side edge. The effect of prying action contributes to the maximum bending strength. Maximum bending strength ratio is 90–60 %.