| 種別 | paper |
| 主題 | Cyclic Behavior of Concrete Based on Micromechanics |
| 副題 | |
| 筆頭著者 | Ahmed M. FARAHAT（Graduate School of Nagoya University） |
| 連名者1 | Zhishen WU（Nagoya University） |
| 連名者2 | Tada-aki TANABE（Nagoya University） |
| 連名者3 | |
| 連名者4 | |
| 連名者5 | |
| キーワード | |
| 巻 | 14 |
| 号 | 2 |
| 先頭ページ | 1035 |
| 末尾ページ | 1040 |
| 年度 | 1992 |
| 要旨 | INTRODUCTION In recent years, a large variety of models has been proposed to predict the behavior of concrete. Most of these models are based on the theory of plasticity. However, the classical approach of plasticity, with scalar loading function in order to satisfy the invariance conditions, becomes rather complex. Alternatively, an approach (called microscopic approach) based on the local view of the material properties can be adopted. In the current study, the micromechanical model, originally introduced by the authors for the description of the monotonic behavior of concrete, is extended to predict the cyclic behavior of concrete. The microcracking, which is the most relevant cause of nonlinearity, is assumed to be localized in the thin and thick mortar layers. For this purpose, concrete is idealized to have two kinds of contacts; aggregate-aggregate and aggregate-mortar contacts. The behavior of these contacts is examined and distinguished for both cyclic and virgin loading. Finally an explicit formula which expresses the tangent stiffness matrix of the material as a summation of the contributions of all contacts, inside any representative volume, is derived. The proposed model is in contrast to the Bazant's microplane model, in which the microcracking was assumed to be localized only in the thin mortar layers and the concrete was idealized to have single kind of contact (aggregate-aggregate contact). Moreover, in that model, less attention was focused on the cyclic behavior. The proposed model has shown its capability to verify the test data. CONCLUSIONS In the present study, the cyclic behavior of concrete is investigated through a new microscopic model. A reasonable agreement with the available macroscopic test data is obtained. This shows that the present model is capable of predicting the cyclic behavior of concrete. Also, to have more general understanding of the concrete, a comprehensive experimental work must be conducted not only on the macrolevel but also on the microlevel but with emphasis on the study on the more precise distribution of the contacts and also the strain distribution of the contacts. |
| PDFファイル名 | 014-01-2179.pdf |