抄録
In order to improve durability of building structure at a disastrous earthquake, Rolled Steels for Building Structure (JIS G 3136-1994) were established. In general, such a violent earthquake is followed by several aftershocks of the same level of the earthquake. Remaining mechanical properties of building components and materials under dynamic tension are essential to evaluate the durability at aftershocks and next disastrous earthquake. In this paper, material damage at a disastrous earthquake is simulated by tensile pre-straining at a quasi-static strain rate, 1×10-3s-1. The pre-strained SN490B steel and SM490A steel (one of the conventional steel for building structure) are characterized in tension with a universal material testing machine at the strain rates of 1×10-3s-1 and 1×10-1s-1 and with a high velocity loading machine of a horizontal slingshot type, adopting the one bar method, at 1×103s-1. The difference between the steels is only the level of lower yield stress, that is, yield ratio. No irregular pre-strain and strain rate dependence of any remaining characteristics is found. The feasibility of interchangeability between Charpy absorbed energy and absorbed energy per unit volume in tension is discussed, three problems (the differences of loading mode, deformed volume and impact velocity between them) are specified.
