Study on Dynamic Characteristics of Stainless Steel Structures

本文对不锈钢结构在地震作用下的动力性能进行了试验研究。本研究分为两部分。首先，对应变速率对不锈钢结构接头力学性能的影响进行了实验研究。制备了SUS304和SUS304N2两种不锈钢的原金属和高强度螺栓连接试样，分别进行了单调拉伸加载和循环反加载试验。从试验结果可以得出以下结论：(1)与低碳钢一样，原始金属的0.1、0.2级应力和抗拉强度受应变速率的影响；(2)摩擦型螺栓连接的摩擦极限和滑移载荷受加载速率的影响增大，而低碳钢的摩擦极限和滑移载荷减小。其次，采用振动台试验对SUS304不锈钢结构的动力性能进行了研究。在试验中，梁只使用不锈钢RHS截面来构建所谓的弱梁型一湾一层框架结构，并且设置在振动台上的结构采用已知的过去地震加速度记录进行振动。测试框架的初始刚度可以通过使用等效模量来估算，该等效模量基于从短柱测试结果中获得的0.1%证明应力下的初始杨氏模量和割线模量的平均值。采用0.1%的防应力和等效模量，不锈钢框架的恢复力与水平位移的无因次关系可与低碳钢框架的关系相比较。

In this reseach dynamic properties of stainless steel structures are experimentally investigated, when the structures would be subjected to earthquake shocks. The research consists of two parts.Initially, the effect of strain rate on the mechanical properties of stainless steel structural joint is experimentally investigated. Raw metals and high-strength bolted joint specimens, made of SUS304 and SUS304N2 stainless steels, were prepared for monotonic tensile loading test and cyclic reversed loading test. From the test results, the following conclusions have been drawn.(1) 0.1,0.2proof stresses and tensile strengths of raw metals are affected by strain rate in common with mild steel,(2) The friction limits and the slip loads of friction type bolted joints are increased affected by loading rates, though those of mild steels were decreased.Secondly, dynamic properties of SUS304 stainless steel structures are investigated by employing shaking table experiment. In the experiment, stainless RHS section was only used for the beam to construct so-called weak beam type one bay-one story framed structure, and the structure set on the shaking table was vibrated by using well known past earthquake acceleration records. The initial stiffness of the test frame can be estimated by using an equivalent modulus based on the average of the initial Young's modulus and the secant modulus at the 0.1% proof stress obtained from the stub column test result. The nondimensional relation between the restoring force and horizontal displacement of the stainless steel frame may be comparable with the relation of mild steel frame, by adopting 0.1%proof stress and the equivalent modulus.