Constitutive Equations and Empirical Creep Law of Structural Steel S460 at High Temperatures

Although the constitutive equations at elevated temperatures given in Eurocode 3 Part 1-2 are valid for steel grades up to S460, the experimental data base concerning the mechanical behaviour of this particular high strength fine-grained structural steel is very small. Especially its short time creep behaviour at high temperatures has not yet been analysed. A current research project, predominantly consisting of transient testing of numerous commercial S460 steels, targets a more precise determination of the stresss-train relationships at high temperatures. Additionally, the time-dependent strain components are extracted from test results gained at varying heating rates, and an empirical creep law, based on the concept of temperature-compensated time, is derived. As a result, the constitutive equations can be formulated taking the heating rate into account. The differences in the high temperature load-carrying capacity of steel structures made of S460 according to the research results and under the terms of Eurocode 3 Part 1-2 are assessed.