Microstructure variation and empirical fatigue model of salt rock under cyclic loading
To study the fatigue properties and microstructure variation of salt rock under cyclic loading, uniaxial fatigue tests under different maximum cycling stresses were carried out on salt rock specimens. Meanwhile, scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) instruments were...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SCIENCE PRESS , 16 DONGHUANGCHENGGEN NORTH ST, BEIJING, PEOPLES R CHINA, 100717
2022-04-01
|
| Series: | Rock and Soil Mechanics |
| Subjects: | |
| Online Access: | http://rocksoilmech.whrsm.ac.cn/EN/10.16285/j.rsm.2021.6356 |
| _version_ | 1811248147952828416 |
|---|---|
| author | ZHANG Qiang WANG Jun-bao SONG Zhan-ping FENG Shi-jin ZHANG Yu-wei ZENG Tao |
| author_facet | ZHANG Qiang WANG Jun-bao SONG Zhan-ping FENG Shi-jin ZHANG Yu-wei ZENG Tao |
| author_sort | ZHANG Qiang |
| collection | DOAJ |
| description | To study the fatigue properties and microstructure variation of salt rock under cyclic loading, uniaxial fatigue tests under different maximum cycling stresses were carried out on salt rock specimens. Meanwhile, scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) instruments were utilized to analyze the microstructure variation in salt rock before and after the test. The results indicated that the cracks growth mode in salt rock under cyclic loading is mainly the development of intergranular cracks, and the number of cracks increases with the maximum stress ratio (the ratio of the maximum cycling stress to the uniaxial compressive strength). After cyclic loading (12 000 cycles), the number of large pores and total pores in salt rock both increase, whereas the number of small pores decreases; and with the increase of maximum stress ratio, the increasing number of large pores and total pores and the decreasing number of small pores both increase. When the maximum stress ratio is 0.40 and the cycle number N≤2 000, the numbers of small pores, large pores and total pores all increase with cycle number; but the increase rate of small pores is faster than that of large pores, showing that the pore structure variation in salt rock is dominated by the initiation of small pores. When the maximum stress ratio is 0.40 and the cycle number N > 2 000, the number of large pores and total pores still increase with cycle number, whereas the number of small pores decreases, demonstrating that the formation of large pores accounts for the main change of pore structure. By solving the inverse function of S-shaped function, an empirical fatigue model with simpler form and fewer parameters was established, which can describe the whole process of irreversible deformation development of salt rock with a unified function, and the rationality of the model was verified by the fatigue test results of salt rock. |
| first_indexed | 2024-04-12T15:22:03Z |
| format | Article |
| id | doaj.art-b536e7a15ee24767a668617bda468ec7 |
| institution | Directory Open Access Journal |
| issn | 1000-7598 |
| language | English |
| last_indexed | 2024-04-12T15:22:03Z |
| publishDate | 2022-04-01 |
| publisher | SCIENCE PRESS , 16 DONGHUANGCHENGGEN NORTH ST, BEIJING, PEOPLES R CHINA, 100717 |
| record_format | Article |
| series | Rock and Soil Mechanics |
| spelling | doaj.art-b536e7a15ee24767a668617bda468ec72022-12-22T03:27:24ZengSCIENCE PRESS , 16 DONGHUANGCHENGGEN NORTH ST, BEIJING, PEOPLES R CHINA, 100717Rock and Soil Mechanics1000-75982022-04-01434995100810.16285/j.rsm.2021.6356Microstructure variation and empirical fatigue model of salt rock under cyclic loadingZHANG Qiang0WANG Jun-bao1SONG Zhan-ping2 FENG Shi-jin3ZHANG Yu-wei4ZENG Tao51. School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, China 2. Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, China1. School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, China 2. Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, China1. School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, China 2. Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, China Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China1. School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, China 2. Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, China1. School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, China 2. Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, ChinaTo study the fatigue properties and microstructure variation of salt rock under cyclic loading, uniaxial fatigue tests under different maximum cycling stresses were carried out on salt rock specimens. Meanwhile, scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) instruments were utilized to analyze the microstructure variation in salt rock before and after the test. The results indicated that the cracks growth mode in salt rock under cyclic loading is mainly the development of intergranular cracks, and the number of cracks increases with the maximum stress ratio (the ratio of the maximum cycling stress to the uniaxial compressive strength). After cyclic loading (12 000 cycles), the number of large pores and total pores in salt rock both increase, whereas the number of small pores decreases; and with the increase of maximum stress ratio, the increasing number of large pores and total pores and the decreasing number of small pores both increase. When the maximum stress ratio is 0.40 and the cycle number N≤2 000, the numbers of small pores, large pores and total pores all increase with cycle number; but the increase rate of small pores is faster than that of large pores, showing that the pore structure variation in salt rock is dominated by the initiation of small pores. When the maximum stress ratio is 0.40 and the cycle number N > 2 000, the number of large pores and total pores still increase with cycle number, whereas the number of small pores decreases, demonstrating that the formation of large pores accounts for the main change of pore structure. By solving the inverse function of S-shaped function, an empirical fatigue model with simpler form and fewer parameters was established, which can describe the whole process of irreversible deformation development of salt rock with a unified function, and the rationality of the model was verified by the fatigue test results of salt rock.http://rocksoilmech.whrsm.ac.cn/EN/10.16285/j.rsm.2021.6356salt rockcyclic loadingmicrostructuresemnmrempirical fatigue model |
| spellingShingle | ZHANG Qiang WANG Jun-bao SONG Zhan-ping FENG Shi-jin ZHANG Yu-wei ZENG Tao Microstructure variation and empirical fatigue model of salt rock under cyclic loading Rock and Soil Mechanics salt rock cyclic loading microstructure sem nmr empirical fatigue model |
| title | Microstructure variation and empirical fatigue model of salt rock under cyclic loading |
| title_full | Microstructure variation and empirical fatigue model of salt rock under cyclic loading |
| title_fullStr | Microstructure variation and empirical fatigue model of salt rock under cyclic loading |
| title_full_unstemmed | Microstructure variation and empirical fatigue model of salt rock under cyclic loading |
| title_short | Microstructure variation and empirical fatigue model of salt rock under cyclic loading |
| title_sort | microstructure variation and empirical fatigue model of salt rock under cyclic loading |
| topic | salt rock cyclic loading microstructure sem nmr empirical fatigue model |
| url | http://rocksoilmech.whrsm.ac.cn/EN/10.16285/j.rsm.2021.6356 |
| work_keys_str_mv | AT zhangqiang microstructurevariationandempiricalfatiguemodelofsaltrockundercyclicloading AT wangjunbao microstructurevariationandempiricalfatiguemodelofsaltrockundercyclicloading AT songzhanping microstructurevariationandempiricalfatiguemodelofsaltrockundercyclicloading AT fengshijin microstructurevariationandempiricalfatiguemodelofsaltrockundercyclicloading AT zhangyuwei microstructurevariationandempiricalfatiguemodelofsaltrockundercyclicloading AT zengtao microstructurevariationandempiricalfatiguemodelofsaltrockundercyclicloading |