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GUO J P, YANG Y G, ZHANG W,et al.Experimental study on dynamic damage and failure characteristics of blue sandstone after high temperature[J].Journal of Henan Polytechnic University(Natural Science) ,2023,42(2):160-165.

高温后砂岩动态损伤与破坏特征试验研究

郭进平1, 杨延光1, 张雯1, 李亚超2

1.西安建筑科技大学 资源工程学院，陕西 西安 710055；2.河南理工大学 土木工程学院，河南 焦作 454000

摘要:为研究高温后砂岩动态损伤与破坏特征，制备常温25 ℃和高温200，400，600，800，1 000 ℃砂岩试样，利用霍普金森压杆（SHPB）试验系统对试样开展冲击试验，得到不同温度下应力‐应变曲线，分析砂岩峰值强度、平均模量与温度的变化关系，研究砂岩破碎程度随冲击气压和加热温度的变化规律，利用扫描电镜（SEM）观测高温破坏后砂岩试样的断口形貌，从微观角度解释高温后砂岩动态损伤与破坏特征改变的成因。结果表明：砂岩试样峰值强度和平均模量随温度升高而减小，600 ℃以下减小速率较慢，600 ℃以上减小速率较快，即600 ℃为砂岩力学强度的拐点；温度升高，砂岩内部微裂隙不断扩展贯通，在冲击作用下微裂隙破碎程度愈发严重，宏观上动态力学性能不断劣化。

关键词:高温;霍普金森压杆试验系统;砂岩动力特性;扫描电镜;破坏特征

doi:10.16186/j.cnki.1673-9787.2021010118

基金项目:国家自然科学基金资助项目（51904220）

收稿日期:2021/01/25

修回日期:2021/03/08

出版日期:2023/03/25

Experimental study on dynamic damage and failure characteristics of blue sandstone after high temperature

GUO Jinping1, YANG Yanguang1, ZHANG Wen1, LI Yachao2

1.School of Resource Engineering，Xi’an University of Architecture and Technology，Xi’an 710055，Shaanxi，China；2.School of Civil Engineering，Henan Polytechnic University，Jiaozuo 454000，Henan，China

Abstract:In order to study the dynamic damage and damage characteristics of blue sandstone after high temperature，the specimens of blue sandstone after 25 ℃ （room temperature）and high temperature of 200 ℃，400 ℃，600 ℃，800 ℃ and 1 000 ℃ were prepared.The split Hopkinson pressure bar （SHPB） test system was used to carry out impact test of blue sandstone specimens under different impact pressure conditions.The stress-strain curves were gotten under different temperatures，and the relationship between the peak strength and average modulus of blue sandstone specimens and the impact pressure was analyzed.The damage degree change laws with the impact pressure and heating temperature were studied.In addition，the scanning electron microscope（SEM） was used to test the fracture of the damaged specimens，and the change causes of dynamic damage and failure characteristics of green sandstone after high temperature were explained from the microscopic point of view.The test results showed that the peak strength and average modulus of green sandstone specimens after high temperature decreased with the increase of temperature，the decreasing rate was slower below 600 ℃ and faster above 600 ℃，that was，600 ℃ was the inflection point of mechanical strength of green sandstone specimens. With the increase of heating temperature， the internal micro-cracks of the blue sandstone continued to expand and penetrate，and the degree of fragmentation under the impact became more serious，which eventually led to the continuous degradation of its macroscopic dynamic mechanical properties.

Key words:high temperature;SHPB test equipment;sandstone dynamic property;SEM;damage characteristic

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