Experimental investigation of static damage of concrete beam underbendingshear based on acoustic emission technology(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2019年02期
- Page:
- 73-81
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Experimental investigation of static damage of concrete beam underbendingshear based on acoustic emission technology
- Author(s):
- YUAN Ming1; HUANG Lian1; PENG Zhuo1; YAN Donghuang1; LIU Yun2
- (1. School of Civil Engineering, Changsha University of Science and Technology, Changsha 410114, Hunan,China； 2. School of Road and Bridge Engineering, Hunan Communication Engineering Polytechnic,Changsha 410132, Hunan, China)
- Keywords:
- bridge engineering; acoustic emission technology; shear test; crack propagation; damage assessment; cumulative acoustic emission events
- PACS:
- -
- DOI:
- -
- Abstract:
- An experimental of a shear test of concrete beams at the specimen and component level was applied, to quantitative evaluate the damage based on the acoustic emission (AE) parameters. The damage process of a concrete beam was dynamically monitored using the AE technique. Concrete damage assessment techniques based on the characteristics of the AE theory were summarized, and an improved damage model was proposed. The quantitative relationship between the AE parameters and the stress level was established using a cubic polynomial model, and a damage evolution equation of concrete beam was developed. Then the validity and accuracy quantitative evaluation of concrete beam damage by damage evolution equation were verified, compared with the existing damage model. The results show that the AE cumulative number changes in three stages，the AE signal is active during the linear development stage, with a relative stress level of 0% to 40%, and that relate to the material contains many microcracks. The cumulative number of AE events and the impact number steadily increase during the stable growth phase. Further, the development of microcracks inside the concrete is stable and slow, with a relative stress level of 40% to 80%. The AE cumulative number drastically increases during the instability phase, where the relative stress level is over 80%, and the internal crack specimen reaches an unstable extended state. The AE cumulative event curve can better describes the entire damage process of a concrete beam, the amount of calculated damage quickly increases through the improved damage evolution model, tends to smooth at the midterm stage, and increases rapidly when the stress level is over 0.8 until the specimen fails. The damage evolution model properly reflects the three stages of concrete damage development. The specimen or component is also damaged when the relative stress level is low, according to damage degree calculating through the damage model.
Last Update: 2019-04-01