Most structural health monitoring systems estimate the overall behavior by measuring the acceleration response, which cannot directly measure the stress or damage state of individual structural members. An alternative approach is to use strain measurements; however, methods for analyzing and utilizing strain data for actual steel buildings have not been established. In this study, highly precise semiconductor strain gauges were applied to an actual building. The accelerations and strains measured during earthquake loading were used to calculate the ratio of the bending moment at the beam or column sections to the displacement at the top of the building, which was defined as the “local stiffness.” This physical index represents the stiffness of structural elements near the measurement location and can be easily predicted through simple static frame analysis. The measured local stiffness was comparable to the analytical local stiffness values for the beams but was larger than that for the columns. This indicates that nonstructural members may exhibit a certain degree of restoring force and that the measured local stiffness may be strongly affected by nonstructural elements that are not considered during the structural design stage. Conversely, the measured local stiffness can be used to estimate the behavior of nonstructural components. The measured dominant frequency and local stiffness of the beams and columns showed a dependency on amplitude, but opposite trends were observed for the beams and columns. This indicates that the amplitude dependency of the dominant frequency is not due to the behavior of the beams and columns but to other reasons such as nonstructural components or changes in mass.

大多数结构健康监测系统通过测量加速度响应来估计总体行为，而加速度响应不能直接测量单个结构构件的应力或损坏状态。另一种方法是使用应变测量。但是，尚未建立用于实际钢结构的分析和利用应变数据的方法。在这项研究中，将高精度半导体应变仪应用于实际建筑物。在地震荷载作用下测得的加速度和应变用于计算梁或柱截面处的弯矩与建筑物顶部位移的比值，即“局部刚度”。该物理指标表示测量位置附近结构元件的刚度，可以通过简单的静态框架分析轻松预测。测得的局部刚度与梁的分析局部刚度值相当，但大于柱的分析局部刚度值。这表明非结构构件可能会表现出一定程度的恢复力，并且所测量的局部刚度可能会受到在结构设计阶段未考虑的非结构元件的强烈影响。相反，测得的局部刚度可用于估计非结构部件的行为。测得的梁和柱的主频和局部刚度显示出对振幅的依赖性，但观察到相反的趋势。