鉄筋コンクリート耐震要素の復元力特性 (その 5) : 崩壊に至る復元力特性とそのモデル化の方法

Abstract

The main purpose of this paper is to establish a hysteresis model that can predict the force-deformation characteristics for wide deformation region as realistically as possible. To begin with, restoring force characteristics is examined based on the results of several experiments of reinforced concrete aseismatic elements, such as one bay portal frames, frames with diagonal bracings and frames with shear wall. As a result of this examination, we can find some interesting remarks as follows that Normalized Characteristic Loops can be established even in large deformation region. And also, in case of non-symmetric hysteresis loops as well as in case of symmetric loops, we can derive Normalized Characteristics Loops that are inherent in each aseismatic element individually. In large deformation region, deterioration phenomina due to alternately reversible loadings are observed quite remarkably on various aspects. Two of these aspects, i. e. stiffness degradation and strength degradation, are investigated. However, the other aspects cannot be investigated due to insufficient data. Subsequently, a mathematical model which represents force-deformation relationship for wide deformation region extending from beginning up to the state of ultimate collapseis decribed. This model is developed by improving so called NCL model that should represent hysteretic behaviour at any stage by connecting the Skeleton Curve with the Normalized Characteristic Loop. And this improved model can represent the phenomenon of degradation in rather simple manner. Lastly, brief comparisons of the experimental results with calculated results are made. And a satisfactory result is obtained.