| 種別 | paper |
| 主題 | AN ANALYTICAL MODEL OF FATIGUE CRACK GROWTH IN CONCRETE |
| 副題 | |
| 筆頭著者 | Hideyuki HORII（University of Tokyo） |
| 連名者1 | Tirath Manojya Pallewatta（Asia Institute of Technology） |
| 連名者2 | Hak Chul SHIN（Asia Institute of Technology） |
| 連名者3 | |
| 連名者4 | |
| 連名者5 | |
| キーワード | |
| 巻 | 12 |
| 号 | 2 |
| 先頭ページ | 841 |
| 末尾ページ | 846 |
| 年度 | 1990 |
| 要旨 | INTRODUCTION Recently a remarkable progress has been accomplished in the application of fracture mechanics to concrete. The existence of fracture process zone is identified and governing mechanisms are clarified. Although analytical prediction of crack growth phenomena under static loading has been enabled, mechanism of fatigue crack growth under cyclic loading has not been studied. In the present study an analytical model of fatigue crack growth in concrete is proposed in order to identify its governing mechanism. Consideration is based on the tension-softening behavior of concrete under cyclic load. Low-cycle fatigue crack growth tests are carried out where the distribution of crack opening displacement is measured by laser speckle method. Experimental results are compared with analytical predictions by the proposed model to discuss the mechanism of fatigue crack growth. CONCLUDING REMARKS In general, fatigue process consists of initiation phase and propagation phase. In the present study, an existing crack is assumed and only propagation of the crack is considered. Even in this situation, the initiation process may play some roles since stress is cycled ahead of the crack tip. This effect is related to the cyclic behavior in pre-peak nonlinear stage of tensile test. In the present model cyclic effect in the unloading part (the proportional relation with reduced slope) is not taken into account unless the point reaches the tension-softening curve. This effect should be clarified and included in the model. The present model predicts arrest of crack extension after several cycles when the load level is low. Hence the model cannot be applied to high-cycle fatigue. The two points mentioned above seem to be closely related to the behavior in high-cycle fatigue. The study on the mechanism of fatigue crack growth has just started. Extensive studies from both theoretical and experimental point of view must be continued to fully understand fatigue phenomena in concrete. |
| PDFファイル名 | 012-01-2142.pdf |