气候变化领域集成服务门户(CCPortal): Microstructural Controls on Thermal Crack Damage and the Presence of a Temperature-Memory Effect During Cyclic Thermal Stressing of Rocks

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DOI	10.1029/2020GL088693
	Microstructural Controls on Thermal Crack Damage and the Presence of a Temperature-Memory Effect During Cyclic Thermal Stressing of Rocks
	Daoud A.; Browning J.; Meredith P.G.; Mitchell T.M.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:19
英文摘要	We present results from a series of thermal stressing experiments that used three igneous rocks of different composition, grain size, and origin and contemporaneously recorded acoustic emissions (AEs) with changing temperature. Samples were subjected to both a single heating and cooling cycle and multiple heating/cooling cycles to different peak temperatures. The vast majority of thermal crack damage is generated during heating in the coarser-grained (quartz rich) rock but during cooling in the two finer-grained (quartz poor) rocks. Our AE results also demonstrate the presence of a temperature-memory effect, analogous to the Kaiser stress-memory effect observed during cyclic mechanical loading, but only in the coarser-grained rock. We suggest that the total amount of crack damage induced during either heating or cooling is dependent on the mineral composition and, most importantly, the grain size and arrangement, as well as the maximum temperature to which the rock was exposed. We use our laboratory-scale results to suggest ways in which crustal-scale geophysical data may need to be reinterpreted to provide more accurate estimates of total, accumulated damage and the approach to macroscopic failure in crustal segments hosting magma chambers and geothermal reservoirs. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Cooling; Cracks; Geothermal fields; Grain size and shape; Heating; Igneous rocks; Quartz; Stress analysis; Thermal stress; Changing temperature; Cyclic mechanical loading; Geothermal reservoir; Heating and cooling cycles; Maximum temperature; Microstructural control; Mineral composition; Temperature memory effects; Acoustic emission testing; acoustic method; chemical composition; cooling; crack; grain size; heating; igneous rock; microstructure; temperature
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/169681
作者单位	Department of Earth Sciences, University College London, London, United Kingdom; Department of Mining Engineering and Department of Structural and Geotechnical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile; Andean Geothermal Centre of Excellence (CEGA), Santiago, Chile
推荐引用方式 GB/T 7714	Daoud A.,Browning J.,Meredith P.G.,et al. Microstructural Controls on Thermal Crack Damage and the Presence of a Temperature-Memory Effect During Cyclic Thermal Stressing of Rocks[J],2020,47(19).
APA	Daoud A.,Browning J.,Meredith P.G.,&Mitchell T.M..(2020).Microstructural Controls on Thermal Crack Damage and the Presence of a Temperature-Memory Effect During Cyclic Thermal Stressing of Rocks.Geophysical Research Letters,47(19).
MLA	Daoud A.,et al."Microstructural Controls on Thermal Crack Damage and the Presence of a Temperature-Memory Effect During Cyclic Thermal Stressing of Rocks".Geophysical Research Letters 47.19(2020).