Junchao Chen, Zhenglu Che, Meiben Gao, Liang Zhang, Zhonghui Shen
{"title":"真三维压缩条件下端面效应对岩石力学行为的实验研究","authors":"Junchao Chen, Zhenglu Che, Meiben Gao, Liang Zhang, Zhonghui Shen","doi":"10.1002/ese3.1856","DOIUrl":null,"url":null,"abstract":"<p>In true triaxial compression tests, all three principal stresses are imposed independently. This allows for a more comprehensive analysis of the material's mechanical properties. The end effect in true triaxial compression tests is a crucial phenomenon that impacts the accuracy and reliability of the test results. In this study, a series of true triaxial compression tests is conducted to examine the influence of the end friction on the mechanical properties. The laboratory results show that the presence of the end friction could bring about an apparent increase in rock strength and also restrict the deformation in each direction showing that the stiffness (the slope of the curves) increased slightly. The rock strength <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <msub>\n <mi>σ</mi>\n \n <mrow>\n <mn>1</mn>\n \n <mo>,</mo>\n \n <mtext>peak</mtext>\n </mrow>\n </msub>\n </mrow>\n </mrow>\n <annotation> ${\\sigma }_{1,\\text{peak}}$</annotation>\n </semantics></math> could be enhanced from 24.7<span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mo>%</mo>\n <mspace></mspace>\n \n <mrow>\n <mo>(</mo>\n \n <mrow>\n <msub>\n <mi>σ</mi>\n \n <mn>2</mn>\n </msub>\n \n <mo>=</mo>\n \n <msub>\n <mi>σ</mi>\n \n <mn>3</mn>\n </msub>\n </mrow>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n </mrow>\n <annotation> $ \\% \\,({\\sigma }_{2}={\\sigma }_{3})$</annotation>\n </semantics></math> to 90.7<span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mo>%</mo>\n </mrow>\n </mrow>\n <annotation> $ \\% $</annotation>\n </semantics></math> (<span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <msub>\n <mi>σ</mi>\n \n <mn>2</mn>\n </msub>\n \n <mo>=</mo>\n \n <msub>\n <mi>σ</mi>\n \n <mn>1</mn>\n </msub>\n </mrow>\n </mrow>\n <annotation> ${\\sigma }_{2}={\\sigma }_{1}$</annotation>\n </semantics></math>) when the end friction is increased, which is mainly caused by the lateral interface friction. The failure mode and fracture angle of the specimen are also influenced by the end effect, showing that under high friction conditions, the failure is more ductile, and a larger fracture angle is observed. At last, in comparison with the published experimental data, the actual specific friction angle <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mn>11</mn>\n \n <mo>°</mo>\n </mrow>\n </mrow>\n <annotation> $11^\\circ $</annotation>\n </semantics></math> (corresponding friction coefficient is about 0.19) for the direct specimen–metal contacts in a true 3D test is numerically identified, which is empirically reasonable and higher than the tested range 0.146–0.157 obtained from double-shear test system.</p>","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":"12 9","pages":"3907-3920"},"PeriodicalIF":3.5000,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ese3.1856","citationCount":"0","resultStr":"{\"title\":\"Experimental study of the end effect on the mechanical behaviors of rocks under true 3D compressions\",\"authors\":\"Junchao Chen, Zhenglu Che, Meiben Gao, Liang Zhang, Zhonghui Shen\",\"doi\":\"10.1002/ese3.1856\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>In true triaxial compression tests, all three principal stresses are imposed independently. This allows for a more comprehensive analysis of the material's mechanical properties. The end effect in true triaxial compression tests is a crucial phenomenon that impacts the accuracy and reliability of the test results. In this study, a series of true triaxial compression tests is conducted to examine the influence of the end friction on the mechanical properties. The laboratory results show that the presence of the end friction could bring about an apparent increase in rock strength and also restrict the deformation in each direction showing that the stiffness (the slope of the curves) increased slightly. The rock strength <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <msub>\\n <mi>σ</mi>\\n \\n <mrow>\\n <mn>1</mn>\\n \\n <mo>,</mo>\\n \\n <mtext>peak</mtext>\\n </mrow>\\n </msub>\\n </mrow>\\n </mrow>\\n <annotation> ${\\\\sigma }_{1,\\\\text{peak}}$</annotation>\\n </semantics></math> could be enhanced from 24.7<span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mo>%</mo>\\n <mspace></mspace>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mrow>\\n <msub>\\n <mi>σ</mi>\\n \\n <mn>2</mn>\\n </msub>\\n \\n <mo>=</mo>\\n \\n <msub>\\n <mi>σ</mi>\\n \\n <mn>3</mn>\\n </msub>\\n </mrow>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n </mrow>\\n <annotation> $ \\\\% \\\\,({\\\\sigma }_{2}={\\\\sigma }_{3})$</annotation>\\n </semantics></math> to 90.7<span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mo>%</mo>\\n </mrow>\\n </mrow>\\n <annotation> $ \\\\% $</annotation>\\n </semantics></math> (<span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <msub>\\n <mi>σ</mi>\\n \\n <mn>2</mn>\\n </msub>\\n \\n <mo>=</mo>\\n \\n <msub>\\n <mi>σ</mi>\\n \\n <mn>1</mn>\\n </msub>\\n </mrow>\\n </mrow>\\n <annotation> ${\\\\sigma }_{2}={\\\\sigma }_{1}$</annotation>\\n </semantics></math>) when the end friction is increased, which is mainly caused by the lateral interface friction. The failure mode and fracture angle of the specimen are also influenced by the end effect, showing that under high friction conditions, the failure is more ductile, and a larger fracture angle is observed. At last, in comparison with the published experimental data, the actual specific friction angle <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mn>11</mn>\\n \\n <mo>°</mo>\\n </mrow>\\n </mrow>\\n <annotation> $11^\\\\circ $</annotation>\\n </semantics></math> (corresponding friction coefficient is about 0.19) for the direct specimen–metal contacts in a true 3D test is numerically identified, which is empirically reasonable and higher than the tested range 0.146–0.157 obtained from double-shear test system.</p>\",\"PeriodicalId\":11673,\"journal\":{\"name\":\"Energy Science & Engineering\",\"volume\":\"12 9\",\"pages\":\"3907-3920\"},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2024-08-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ese3.1856\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Energy Science & Engineering\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/ese3.1856\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ENERGY & FUELS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Energy Science & Engineering","FirstCategoryId":"5","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/ese3.1856","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
Experimental study of the end effect on the mechanical behaviors of rocks under true 3D compressions
In true triaxial compression tests, all three principal stresses are imposed independently. This allows for a more comprehensive analysis of the material's mechanical properties. The end effect in true triaxial compression tests is a crucial phenomenon that impacts the accuracy and reliability of the test results. In this study, a series of true triaxial compression tests is conducted to examine the influence of the end friction on the mechanical properties. The laboratory results show that the presence of the end friction could bring about an apparent increase in rock strength and also restrict the deformation in each direction showing that the stiffness (the slope of the curves) increased slightly. The rock strength could be enhanced from 24.7 to 90.7 () when the end friction is increased, which is mainly caused by the lateral interface friction. The failure mode and fracture angle of the specimen are also influenced by the end effect, showing that under high friction conditions, the failure is more ductile, and a larger fracture angle is observed. At last, in comparison with the published experimental data, the actual specific friction angle (corresponding friction coefficient is about 0.19) for the direct specimen–metal contacts in a true 3D test is numerically identified, which is empirically reasonable and higher than the tested range 0.146–0.157 obtained from double-shear test system.
期刊介绍:
Energy Science & Engineering is a peer reviewed, open access journal dedicated to fundamental and applied research on energy and supply and use. Published as a co-operative venture of Wiley and SCI (Society of Chemical Industry), the journal offers authors a fast route to publication and the ability to share their research with the widest possible audience of scientists, professionals and other interested people across the globe. Securing an affordable and low carbon energy supply is a critical challenge of the 21st century and the solutions will require collaboration between scientists and engineers worldwide. This new journal aims to facilitate collaboration and spark innovation in energy research and development. Due to the importance of this topic to society and economic development the journal will give priority to quality research papers that are accessible to a broad readership and discuss sustainable, state-of-the art approaches to shaping the future of energy. This multidisciplinary journal will appeal to all researchers and professionals working in any area of energy in academia, industry or government, including scientists, engineers, consultants, policy-makers, government officials, economists and corporate organisations.