Papers by Keyword: Strength Reduction Factor

Abstract: Torsional test of aluminum foam-filled galvanized steel tube before and after high temperature is performed. The influence of temperature, porosity of aluminum foam and steel ratio on torsional behavior of aluminum foam galvanized steel tubes were analyzed. Experimental results showed that torsional curves of aluminum foam-filled galvanized steel tube before and after high temperature is similar, and can be divided into four stages: the elastic torsional stage, yield platform stage, descent stage and hardening stage; Its torsional load capacity decreases with increasing porosity of aluminum foam and increases at a higher steel content and slenderness ratio; after high temperature, torsional load capacity of galvanized steel tube decreased significantly. It was found that the strength reduction factor ratio under the elevated test temperature is higher than that recommended by British ECCS, Australian AS4100 and Chinese CECS 200-2006.

Abstract: The current local stability criteria (KBC2009, AISC2010) are enacted through theoretical and experimental studies of ordinary steels, but the mechanical properties of high strength steels are different from ordinary steels. The high strength steel in the applicability of design criteria should be needed to review because of increasing market demanding for high strength steel in the high-rise and long span buildings. In this study, stub columns of H-shaped and box section with various steel grades subjected to concentric loading were investigated, and these steels were checked to the applicability of current local stability criteria. The difference between the ordinary steel and high strength steel was compared. As a result of comparison with various steel grades, most specimens were satisfied with the design criteria, but some specimens with lower tensile strength were not reached the required strength. It is considered that the uncertainty of material was the higher when the tensile strength of material was the lower.

Abstract: Generally rupture of steam generator tubes occurs accompanying significant plastic deformation. In this study, the burst pressure of a damaged steam generator tube is calculated from the plastic instability analysis using the finite element method. Two wear types, flat and circumferential types are considered. An equation for the burst pressure is proposed by using the concept of strength reduction factor and the Svensson equation. The analysis results are also compared with the experiment data from published references and they show a good agreement with the experiment data.