| Project/Area Number |
09650516
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
土木材料・力学一般
|
|---|
| Research Institution | Fukushima National College of Technology |
|---|
Principal Investigator |
MASAJI Yamanouchi Fukushima National College of Technology, Civil Engineering, Associate Professor, 建設環境工業科, 助教授 (80132570)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Project Status |
Completed (Fiscal Year 1998)
|
| Budget Amount *help |
¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1998: ¥400,000 (Direct Cost: ¥400,000)
|
|---|
| Keywords | Concrete / Fracture Process Zone / Tension Softening Process / Time Dependence / 3-D AE Source Location / AE Energy / Fractal Dimension / energy of crack formation / 引張軟化則 / アコースティックエミッション / アコースティック・エミッション |
|---|
| Research Abstract |
The fracture parameters such as fracture energy and brittleness are deeply concerned with the cumulative process of micro cracking in the fracture process zone. The purpose of this research is to obtain the time dependent behavior of micro cracking in the fracture process zone of notched concrete beam under constant loadings, using three dimensional AE source location method.
The velocity of the crack mouth opening displacement changes from steady to accelerative state beyond a certain critical point. AE source locations distribute widely in the steady state, and in a line at the front of the fracture process zone after the critical point. This means that the process of accelerative micro craking is connected with the initial state of tension softening.
To research on the critical point, the tension softening diagram is evaluated by means of poly-linear inverse analysis method. On the basis of comparison between AE source locations and the crack type distributions in the fractured cross section, meso-scopic fracture mechanism in tension softening process is considered. It makes clear that the cumulative AE energy is increasing with the same manner of the energy of crack formation. This result suggests that the proposed AE energy represents quantitatively micro cracking in fracture process zone.
In the future, it is necessary to determine the amount of AE energy correspond to the critical point and to investigate the relation between brittleness.
|
