Received: 25 July 2019 Accepted: 1 October 2019 Conventional concrete is prone to cracking under tensile load, despite its good compressive strength. Recently, biological agents have been applied to heal the cracks in concrete, making concrete structures more serviceable. This paper mainly attempts to evaluate the mechanical properties of bacteria-based self-healing concrete. Two bacteria were selected as the bioagents in concrete, namely, Bacillus subtilis and Bacillus halodurans. The concentration of the bioagents were set to 10~10 cell/mL in water. Then, the two bacteria were applied to cracked concrete to cure the cracks. After curing for several days, the bacteria-based self-healing concrete was subjected to compressive and flexural tests to estimate its mechanical parameters. The results show that the self-healing concretes cured for 14d and 28d had a 7% and 18% higher compressive strength than conventional concrete, respectively; the self-healing concretes cured for 14d and 28d had a 11% and 28% higher flexural strength than the conventional concrete, respectively. Thus, the bioagents could effectively heal the surface cracks on concrete, and make the concrete imperviable.
{"title":"Evaluation of Mechanical Parameters of Bacterial Concrete","authors":"C. Durga, N. Ruben, M. Chand, C. Venkatesh","doi":"10.18280/acsm.430606","DOIUrl":"https://doi.org/10.18280/acsm.430606","url":null,"abstract":"Received: 25 July 2019 Accepted: 1 October 2019 Conventional concrete is prone to cracking under tensile load, despite its good compressive strength. Recently, biological agents have been applied to heal the cracks in concrete, making concrete structures more serviceable. This paper mainly attempts to evaluate the mechanical properties of bacteria-based self-healing concrete. Two bacteria were selected as the bioagents in concrete, namely, Bacillus subtilis and Bacillus halodurans. The concentration of the bioagents were set to 10~10 cell/mL in water. Then, the two bacteria were applied to cracked concrete to cure the cracks. After curing for several days, the bacteria-based self-healing concrete was subjected to compressive and flexural tests to estimate its mechanical parameters. The results show that the self-healing concretes cured for 14d and 28d had a 7% and 18% higher compressive strength than conventional concrete, respectively; the self-healing concretes cured for 14d and 28d had a 11% and 28% higher flexural strength than the conventional concrete, respectively. Thus, the bioagents could effectively heal the surface cracks on concrete, and make the concrete imperviable.","PeriodicalId":7897,"journal":{"name":"Annales De Chimie-science Des Materiaux","volume":"40 1","pages":"395-399"},"PeriodicalIF":0.8,"publicationDate":"2019-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79534421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Received: 15 August 2019 Accepted: 6 November 2019 This paper explores deep into the effects of mineral admixtures, e.g. ultrafine ground granulated blast-furnace slag (UFGGBFS) and copper slag (CPS), on ambient cured geopolymer concrete (GPC). First, a GPC was prepared from mineral admixtures like the UFGGBFS, fly ash and the CPS, and alkali activators like sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Then, 10M, 12M and 14M GPC samples were created, with UFGGBFS content of 0%, 5%, 10% and 15%, respectively. These samples were subjected to compressive strength tests, rapid chloride permeability test (RCPT), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results show that the GPC samples achieved good compressive strength after 56 days of ambient curing; with the increase of the UFGGBFS content, the porosities and RCPT values of the samples decreased after 180 days of ambient curing; the samples with different mix ratios all showed good performance with the growth in molar concentration. The research results shed new light on the development of eco-friendly alternatives to cementitious GPC.
{"title":"Effect of Ultrafine Ground Granulated Blast-Furnace Slag (UFGGBFS) and Copper Slag on Ambient Cured Geopolymer Concrete","authors":"V. Rathanasalam, J. Perumalsami, K. Jayakumar","doi":"10.18280/acsm.430603","DOIUrl":"https://doi.org/10.18280/acsm.430603","url":null,"abstract":"Received: 15 August 2019 Accepted: 6 November 2019 This paper explores deep into the effects of mineral admixtures, e.g. ultrafine ground granulated blast-furnace slag (UFGGBFS) and copper slag (CPS), on ambient cured geopolymer concrete (GPC). First, a GPC was prepared from mineral admixtures like the UFGGBFS, fly ash and the CPS, and alkali activators like sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Then, 10M, 12M and 14M GPC samples were created, with UFGGBFS content of 0%, 5%, 10% and 15%, respectively. These samples were subjected to compressive strength tests, rapid chloride permeability test (RCPT), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results show that the GPC samples achieved good compressive strength after 56 days of ambient curing; with the increase of the UFGGBFS content, the porosities and RCPT values of the samples decreased after 180 days of ambient curing; the samples with different mix ratios all showed good performance with the growth in molar concentration. The research results shed new light on the development of eco-friendly alternatives to cementitious GPC.","PeriodicalId":7897,"journal":{"name":"Annales De Chimie-science Des Materiaux","volume":"14 8 Pt 2 1","pages":"377-382"},"PeriodicalIF":0.8,"publicationDate":"2019-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78463119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raïssa Charlie Poudeu, Cyprien Joel Ekani, C. Djangang, P. Blanchart
Received: 12 July 2019 Accepted: 26 November 2019 This paper aims to develop a low-cost, green construction material for low-income house builders. A series of geopolymer samples were prepared by partially substituting the Cameroonian lateritic soil (LS) with different quantities of heat-treated laterite (20~50 wt. %). The chemical composition of the LS was determined through inductively coupled plasma spectroscopy (ICP). The specimens were subjected to thermogravimetric and differential thermal analyses (TGA/DTA), X-ray diffractometry (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). In addition, the compressive strength of dry and wet specimens was measured with a hydroelectric device. The results show that the geo-polymerization and properties like setting time and mechanical strength of the samples were improved through the combined action of the raw LS and the laterite treated at 500-600°C; the crystallized particles from non-clayed minerals and from aggregates of kaolinite also contribute to strength of the samples; crystalline phases formed a tridimensional skeleton in the microstructure of the geopolymer. The research provides a promising composite that can serve as a low-cost construction material with reduced environmental impact.
{"title":"Role of Heat-Treated Laterite on the Strengthening of Geopolymer Designed with Laterite as Solid Precursor","authors":"Raïssa Charlie Poudeu, Cyprien Joel Ekani, C. Djangang, P. Blanchart","doi":"10.18280/acsm.430601","DOIUrl":"https://doi.org/10.18280/acsm.430601","url":null,"abstract":"Received: 12 July 2019 Accepted: 26 November 2019 This paper aims to develop a low-cost, green construction material for low-income house builders. A series of geopolymer samples were prepared by partially substituting the Cameroonian lateritic soil (LS) with different quantities of heat-treated laterite (20~50 wt. %). The chemical composition of the LS was determined through inductively coupled plasma spectroscopy (ICP). The specimens were subjected to thermogravimetric and differential thermal analyses (TGA/DTA), X-ray diffractometry (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). In addition, the compressive strength of dry and wet specimens was measured with a hydroelectric device. The results show that the geo-polymerization and properties like setting time and mechanical strength of the samples were improved through the combined action of the raw LS and the laterite treated at 500-600°C; the crystallized particles from non-clayed minerals and from aggregates of kaolinite also contribute to strength of the samples; crystalline phases formed a tridimensional skeleton in the microstructure of the geopolymer. The research provides a promising composite that can serve as a low-cost construction material with reduced environmental impact.","PeriodicalId":7897,"journal":{"name":"Annales De Chimie-science Des Materiaux","volume":"50 1","pages":"359-367"},"PeriodicalIF":0.8,"publicationDate":"2019-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78254507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. R. Abdulmunem, A. Abed, H. Hussien, P. M. Samin, H. A. Rahman
1 School of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia 2 Ural Federal University Named after the First Persident of Russia B.N.Yeltsin 19Mira str., Yekaterinburg 620002, Russia 3 Electromechanical Engineering Department, University of Technology, Baghdad 10066, Iraq 4 Center of Electrical Energy System, School of Electrical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia
{"title":"Improving the Performance of Solar Air Heater Using High Thermal Storage Materials","authors":"A. R. Abdulmunem, A. Abed, H. Hussien, P. M. Samin, H. A. Rahman","doi":"10.18280/acsm.430605","DOIUrl":"https://doi.org/10.18280/acsm.430605","url":null,"abstract":"1 School of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia 2 Ural Federal University Named after the First Persident of Russia B.N.Yeltsin 19Mira str., Yekaterinburg 620002, Russia 3 Electromechanical Engineering Department, University of Technology, Baghdad 10066, Iraq 4 Center of Electrical Energy System, School of Electrical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia","PeriodicalId":7897,"journal":{"name":"Annales De Chimie-science Des Materiaux","volume":"5 1","pages":"389-394"},"PeriodicalIF":0.8,"publicationDate":"2019-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90332983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, geogrid materials have been widely adopted for high fill slopes of airports in mountainous regions, as they can cope with the heavy earth/stonework, high filling height, complex filler properties and diverse topography. The properties of the soilreinforcement interface (SRI) between geogrids and fillers directly bear on the safety of the reinforced structure. To improve the design of reinforced soil structure, it is imperative to determine the SRI properties in in-situ states, disclose the load transmission law, and identify the effective length of reinforcement strip. This paper carries out in-situ pull-out tests on the high fill slopes of an airport, explores the in-situ pull-out properties of geogrids under longterm, large-scale earth/stonework construction, and analyses the variation laws of parameters like strain, stress and displacement under different pull-out forces. Assuming that the relationship between strain and position is an S-curve, the theoretical relationships between these parameters and geogrid position were derived. Through the comparison against the test results, it is proved that the S-curve model outputted basically the same laws with those observed in the tests. The research findings provide a valuable reference for the design of reinforced soil structure. RÉSUMÉ. Ces dernières années, les matériaux de géogrille ont été largement adoptés pour les pentes de remblayage des aéroports dans les régions montagneuses, car ils peuvent supporter des sols lourds et le maçonnage, une hauteur de remplissage élevée, des propriétés de remplissage complexes et une topographie variée. Les propriétés de l'interface de renforcement de sol (SRI en anglais) entre les géogrilles et les matériaux de remplissage ont une incidence directe sur la sécurité de la structure renforcée. Pour améliorer la conception de la structure de sol renforcée, il est impératif de déterminer les propriétés de l'interface de consolidation de sol dans les états in situ, de divulguer la loi de transmission de la charge et d'identifier la longueur effective de la bande de renforcement. Cet article effectue des tests en retrait in situ sur les pentes de remplissage d'un aéroport, explore les propriétés de retrait in situ des géogrilles dans le cadre de la construction à long terme de terres et de maçonnage, et 42 ACSM. Volume 42 – n° 1/2018 analyse les lois de variation de des paramètres tels que la déformation, la tension et le déplacement sous différentes forces de retrait. En supposant que la relation entre la déformation et la position soit une courbe en S, les relations théoriques entre ces paramètres et la position de la géogrille ont été dérivées. La comparaison avec les résultats des tests a montré que le modèle à courbe en S produisait essentiellement les mêmes lois que celles observées dans les tests. Les résultats de la recherche fournissent une référence précieuse pour la conception de la structure de sol renforcée.
近年来，土工格栅材料被广泛应用于山区机场的高填方边坡，因为它可以应对土石方重、填方高度高、填方性质复杂和地形多变等问题。土工格栅与填料之间的配筋界面性能直接关系到配筋结构的安全性。为了改进加筋土结构的设计，必须确定原位状态下的SRI特性，揭示荷载传递规律，确定配筋有效长度。本文对某机场高填方边坡进行了原位拉拔试验，探讨了土工格栅在长期、大型土石方施工下的原位拉拔性能，分析了不同拉拔力下土工格栅的应变、应力、位移等参数的变化规律。假设应变与位置之间的关系为s曲线，推导了这些参数与土工格栅位置之间的理论关系。通过与试验结果的比较，证明了s曲线模型输出的规律与试验观察到的规律基本一致。研究结果为加筋土结构的设计提供了有价值的参考。的简历。3 . as dernires annacmes, as matriaux de gastogrile and samtagnees, as large adopts, as danci.com/， as danci.com/， as danci.com/， as danci.com/， as danci.com/， as danci.com/， as danci.com/， as danci.com/。由固有的交换交换和交换交换组成的交换交换，直接由交换交换和交换交换组成，直接由交换交换和交换交换组成。将samsamliv的概念定义为结构定义为强制执行的samsamiv，将samsamiv的概念定义为结构定义为强制执行的samsamiv，将samsamiv的接口定义为固定的samsamiv，将samsamiv的接口定义为固定的samsamiv，将samsamiv的接口定义为固定的samsamiv，将samsamiv的接口定义为传输的samsamiv，将samiv的标识符定义为有效的samsamiv。摘要本文探讨了原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性、原位还原试验的有效性等。第42卷- n°1/2018分析了可变参数的变化规律，可变参数的变化规律，可变参数的变化规律，可变参数的变化规律，可变参数的变化规律，可变参数的变化规律，可变参数的变化规律。因此，我们可以将“关系中心”设为“交换交换”，将“交换交换”设为“交换交换”，将“交换交换”设为“交换交换”，将“交换交换交换”设为“交换交换交换”。比较了不同的数据交换器、不同的数据交换器、不同的数据交换器、不同的数据交换器、不同的数据交换器和不同的数据交换器。从研究角度看，这是一种改进的形式，即从结构角度看，这是一种改进的形式。
{"title":"In-situ pull-out tests on soil-reinforcement interface properties of reinforced soil slopes","authors":"Cunjia Qiu, Shuangfei Wang, Hong Liu, Jin Huang","doi":"10.3166/ACSM.42.41-56","DOIUrl":"https://doi.org/10.3166/ACSM.42.41-56","url":null,"abstract":"In recent years, geogrid materials have been widely adopted for high fill slopes of airports in mountainous regions, as they can cope with the heavy earth/stonework, high filling height, complex filler properties and diverse topography. The properties of the soilreinforcement interface (SRI) between geogrids and fillers directly bear on the safety of the reinforced structure. To improve the design of reinforced soil structure, it is imperative to determine the SRI properties in in-situ states, disclose the load transmission law, and identify the effective length of reinforcement strip. This paper carries out in-situ pull-out tests on the high fill slopes of an airport, explores the in-situ pull-out properties of geogrids under longterm, large-scale earth/stonework construction, and analyses the variation laws of parameters like strain, stress and displacement under different pull-out forces. Assuming that the relationship between strain and position is an S-curve, the theoretical relationships between these parameters and geogrid position were derived. Through the comparison against the test results, it is proved that the S-curve model outputted basically the same laws with those observed in the tests. The research findings provide a valuable reference for the design of reinforced soil structure. RÉSUMÉ. Ces dernières années, les matériaux de géogrille ont été largement adoptés pour les pentes de remblayage des aéroports dans les régions montagneuses, car ils peuvent supporter des sols lourds et le maçonnage, une hauteur de remplissage élevée, des propriétés de remplissage complexes et une topographie variée. Les propriétés de l'interface de renforcement de sol (SRI en anglais) entre les géogrilles et les matériaux de remplissage ont une incidence directe sur la sécurité de la structure renforcée. Pour améliorer la conception de la structure de sol renforcée, il est impératif de déterminer les propriétés de l'interface de consolidation de sol dans les états in situ, de divulguer la loi de transmission de la charge et d'identifier la longueur effective de la bande de renforcement. Cet article effectue des tests en retrait in situ sur les pentes de remplissage d'un aéroport, explore les propriétés de retrait in situ des géogrilles dans le cadre de la construction à long terme de terres et de maçonnage, et 42 ACSM. Volume 42 – n° 1/2018 analyse les lois de variation de des paramètres tels que la déformation, la tension et le déplacement sous différentes forces de retrait. En supposant que la relation entre la déformation et la position soit une courbe en S, les relations théoriques entre ces paramètres et la position de la géogrille ont été dérivées. La comparaison avec les résultats des tests a montré que le modèle à courbe en S produisait essentiellement les mêmes lois que celles observées dans les tests. Les résultats de la recherche fournissent une référence précieuse pour la conception de la structure de sol renforcée.","PeriodicalId":7897,"journal":{"name":"Annales De Chimie-science Des Materiaux","volume":"19 1","pages":"41-56"},"PeriodicalIF":0.8,"publicationDate":"2018-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84272895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seshu Kumar Vandrangi, Sampath Emani, K. Sharma, Gurunadh Velidi
The purpose of the current research is to investigate the computational heat transfer coefficients of SiO2 nanoparticles dispersed in ethylene glycol (EG) and water (W) mixtures in 60:40 (60EGW) and 40:60 (40EGW) by volume and evaluate the influence of base fluid. The thermophysical properties of SiO2, based nanoparticles dispersed in 60EGW and 40EGW base fluid were taken from available literature and regression analysis was performed for formulating equations. The theoretical data was used as input in computational analysis for the investigation of heat transfer coefficients. The results indicate that the heat transfer coefficients for SiO2/60EGW and SiO2/40EGW based nanofluids have shown an enhancement of 25% and 55% respectively when compared with base fluids. Hence, it can be concluded that SiO2/40EGW nanofluids show a better heat transfer rates than SiO2/60EGW nanofluids. RÉSUMÉ. L’objet de la recherche actuelle est d’étudier les coefficients de transfert de chaleur calculés de nanoparticules de SiO2 dispersées dans des mélanges d’éthylène glycol (EG) et d’eau (W) à 60 :40 (60EGW) et 40 :60 (40EGW) en volume, et d'évaluer de fluide de base. Les propriétés thermo physiques de nanoparticules à base de SiO2, dispersées dans un fluide de base 60EGW et 40EGW ont été tirées de la littérature disponible et une analyse de régression a été réalisée pour la formulation d'équations. Les données théoriques ont été utilisées comme entrée dans l'analyse informatique pour l'étude des coefficients de transfert de chaleur. Les résultats indiquent que les coefficients de transfert de chaleur pour les nano fluides à base de SiO2 / 60EGW et de SiO2 / 40EGW ont montré une amélioration de 25% et 55% respectivement par rapport aux fluides de base. On peut donc en conclure que les nano fluides SiO2 / 40EGW présentent un meilleur taux de transfert de chaleur que les nano fluides SiO2 / 60EGW. 104 ACSM. Volume 42 – n° 1/2018
本研究的目的是研究SiO2纳米颗粒在体积为60:40 (60EGW)和40:60 (40EGW)的乙二醇(EG)和水(W)混合物中分散的计算换热系数，并评估基液的影响。从现有文献中获取分散在60EGW和40EGW基液中的SiO2纳米颗粒的热物理性质，并进行回归分析以建立方程。将理论数据作为换热系数计算分析的输入。结果表明，与基液相比，SiO2/60EGW和SiO2/40EGW纳米流体的换热系数分别提高了25%和55%。综上所述，SiO2/40EGW纳米流体的传热速率优于SiO2/60EGW纳米流体。的简历。L ' object de la recherche actuelle est d' sameter de transferer coefficients de chaleur calcules de sametes de nanopparticles de SiO2分散的sametes de sametes de sametes de sametes de sametes de sametes de sametes de sametlo (W) 60:40 (60EGW) and 40:60 (40EGW)体积，et d' sameter de fluidde碱。将固有的热物理性质的纳米粒子，如基基SiO2，分散的基基SiO2，分散的基基SiO2，分散的基基SiO2，分散的基基基SiO2，分散的基基基SiO2，分散的基基基SiO2，分散的基基基SiO2，分散的基基基SiO2，分散的基基基SiO2，分散的基基基SiO2，分散的基基基SiO2，分散的基基基SiO2，分散的基基基SiO2，分散的基基基SiO2，一次性的基基基SiO2，分别分析基基基SiO2和基基基SiO2的基基基SiO2。“不，不，不，不，不，不，不，不，不，不，不，不，不，不，不，不，不，不。”对纳米流体(SiO2 / 60EGW)和纳米流体(SiO2 / 40EGW)分别进行25%和55%的分离，对纳米流体(SiO2 / 40EGW)进行分离。在此基础上，研究了纳米流体SiO2 / 40EGW和纳米流体SiO2 / 60EGW的传输特性。104 ACSM。卷42 - n°1/2018
{"title":"Computational analysis to determine the heat transfer coefficients for SiO2/60EGW and SiO2/40EGW based nano-fluids","authors":"Seshu Kumar Vandrangi, Sampath Emani, K. Sharma, Gurunadh Velidi","doi":"10.3166/ACSM.42.103-114","DOIUrl":"https://doi.org/10.3166/ACSM.42.103-114","url":null,"abstract":"The purpose of the current research is to investigate the computational heat transfer coefficients of SiO2 nanoparticles dispersed in ethylene glycol (EG) and water (W) mixtures in 60:40 (60EGW) and 40:60 (40EGW) by volume and evaluate the influence of base fluid. The thermophysical properties of SiO2, based nanoparticles dispersed in 60EGW and 40EGW base fluid were taken from available literature and regression analysis was performed for formulating equations. The theoretical data was used as input in computational analysis for the investigation of heat transfer coefficients. The results indicate that the heat transfer coefficients for SiO2/60EGW and SiO2/40EGW based nanofluids have shown an enhancement of 25% and 55% respectively when compared with base fluids. Hence, it can be concluded that SiO2/40EGW nanofluids show a better heat transfer rates than SiO2/60EGW nanofluids. RÉSUMÉ. L’objet de la recherche actuelle est d’étudier les coefficients de transfert de chaleur calculés de nanoparticules de SiO2 dispersées dans des mélanges d’éthylène glycol (EG) et d’eau (W) à 60 :40 (60EGW) et 40 :60 (40EGW) en volume, et d'évaluer de fluide de base. Les propriétés thermo physiques de nanoparticules à base de SiO2, dispersées dans un fluide de base 60EGW et 40EGW ont été tirées de la littérature disponible et une analyse de régression a été réalisée pour la formulation d'équations. Les données théoriques ont été utilisées comme entrée dans l'analyse informatique pour l'étude des coefficients de transfert de chaleur. Les résultats indiquent que les coefficients de transfert de chaleur pour les nano fluides à base de SiO2 / 60EGW et de SiO2 / 40EGW ont montré une amélioration de 25% et 55% respectivement par rapport aux fluides de base. On peut donc en conclure que les nano fluides SiO2 / 40EGW présentent un meilleur taux de transfert de chaleur que les nano fluides SiO2 / 60EGW. 104 ACSM. Volume 42 – n° 1/2018","PeriodicalId":7897,"journal":{"name":"Annales De Chimie-science Des Materiaux","volume":"15 1","pages":"103-114"},"PeriodicalIF":0.8,"publicationDate":"2018-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89006362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Since times immemorial it is known that the application of a material classified as lubricant to two relatively moving surfaces causes motion. The real mechanism of lubrication was explained by Reynolds of the role of lubricants is to support the load between two moving curved surfaces and thus minimizing wear and energy losses reducing friction between them. Thus the proper knowledge and understanding of the process of lubrication becomes a prime necessity to improve standard of design and efficiency of the mechanical system. A study of the behavior of any lubricated system can be best made by developing a mathematical model based on the above factors which depends upon a given a physical situation. The bearing characteristics such as load, flow flux, friction force etc. depends upon the pressure generated in the film and the lubrication process. An attempt has been made to obtain the governing equation for pressure in the lubricant film that are surveyed and summarized in this paper. RÉSUMÉ. Depuis des temps immémoriaux, il est connu que l'application d'un matériau classé comme lubrifiant sur deux surfaces relativement mobiles provoque un mouvement.Le mécanisme réel de lubrification a été expliqué par Reynolds que le rôle de lubrifiants est de supporter la charge entre deux surfaces courbes en mouvement, minimisant ainsi l'usure et les pertes d'énergie, réduisant ainsi les frictions entre elles.Ainsi, la connaissance et la compréhension appropriées du processus de lubrification deviennent une nécessité primordiale pour améliorer les normes de conception et l'efficacité du système mécanique.Une étude du comportement de tout système lubrifié peut être mieux réalisée en développant un modèle mathématique basé sur les facteurs ci-dessus, qui dépend d'une situation physique donnée. Les caractéristiques des roulements, telles que la charge, le flux, la force de friction, etc., dépendent de la pression générée dans le film et du processus de lubrification.Une tentative a été faite pour obtenir l'équation régissant la pression dans le film de lubrifiant qui sont enquêtés et résumées dans le présent document.
自古以来，人们就知道，将一种被归类为润滑剂的材料应用于两个相对运动的表面会引起运动。雷诺兹解释了润滑的真正机制，润滑剂的作用是支持两个运动曲面之间的载荷，从而最大限度地减少磨损和能量损失，减少它们之间的摩擦。因此，正确认识和理解润滑过程是提高机械系统设计水平和效率的必要条件。要研究任何润滑系统的行为，最好的方法是根据上述因素建立数学模型，而这些因素取决于给定的物理情况。负载、流量、摩擦力等轴承特性取决于膜内产生的压力和润滑过程。本文对所调查和总结的润滑油膜压力的控制方程进行了尝试。的简历。“Depuis des temps imsammoriaux, il est connu que l'application d'un matsamriau classscomme”润滑油表面关系移动激起运动。在运动过程中，有最小的摩擦，最小的摩擦，最小的摩擦，最小的摩擦，最小的摩擦，最小的摩擦，最小的摩擦。例如，从概念上说，从概念上说，从系统上说，从效率上说，从概念上说，从效率上说，从系统上说，从本质上说，从本质上说，从本质上说，从本质上说，从本质上说，从本质上说，从本质上说，从本质上说，从本质上说，这是不可能的。一个系统的性能和润滑系统的性能都是相同的，例如:将所有的系统的性能和润滑系统的性能结合在一起，将所有的系统的性能和润滑系统的性能结合在一起。caracacimristiques des roulements, telles que la charge, le flux, la force de friction，等等，acacimpendent de la pression, acacimacentresandle film et du process de润滑。一个初步的疾病结果倒obtenir等式regissant拉压力在电影de lubrifiant是这个外星人的简历在当前文档。
{"title":"Effects of viscosity variation and thermal effects in squeeze films","authors":"E. Mamatha, C. Reddy, Rohit Sharma","doi":"10.3166/ACSM.42.57-74","DOIUrl":"https://doi.org/10.3166/ACSM.42.57-74","url":null,"abstract":"Since times immemorial it is known that the application of a material classified as lubricant to two relatively moving surfaces causes motion. The real mechanism of lubrication was explained by Reynolds of the role of lubricants is to support the load between two moving curved surfaces and thus minimizing wear and energy losses reducing friction between them. Thus the proper knowledge and understanding of the process of lubrication becomes a prime necessity to improve standard of design and efficiency of the mechanical system. A study of the behavior of any lubricated system can be best made by developing a mathematical model based on the above factors which depends upon a given a physical situation. The bearing characteristics such as load, flow flux, friction force etc. depends upon the pressure generated in the film and the lubrication process. An attempt has been made to obtain the governing equation for pressure in the lubricant film that are surveyed and summarized in this paper. RÉSUMÉ. Depuis des temps immémoriaux, il est connu que l'application d'un matériau classé comme lubrifiant sur deux surfaces relativement mobiles provoque un mouvement.Le mécanisme réel de lubrification a été expliqué par Reynolds que le rôle de lubrifiants est de supporter la charge entre deux surfaces courbes en mouvement, minimisant ainsi l'usure et les pertes d'énergie, réduisant ainsi les frictions entre elles.Ainsi, la connaissance et la compréhension appropriées du processus de lubrification deviennent une nécessité primordiale pour améliorer les normes de conception et l'efficacité du système mécanique.Une étude du comportement de tout système lubrifié peut être mieux réalisée en développant un modèle mathématique basé sur les facteurs ci-dessus, qui dépend d'une situation physique donnée. Les caractéristiques des roulements, telles que la charge, le flux, la force de friction, etc., dépendent de la pression générée dans le film et du processus de lubrification.Une tentative a été faite pour obtenir l'équation régissant la pression dans le film de lubrifiant qui sont enquêtés et résumées dans le présent document.","PeriodicalId":7897,"journal":{"name":"Annales De Chimie-science Des Materiaux","volume":"56 1","pages":"57-74"},"PeriodicalIF":0.8,"publicationDate":"2018-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73381682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The purpose of this study was to designed and fabricated a 10 kg capacity forced convection solar dryer integrated with thermal energy storage materials, TSMA and TSMB, using locally sourced and low-cost materials for drying agricultural products. The dryer consists mainly of a well-insulated solar collector, drying chamber and photovoltaic components. The maximum collector and drying chamber temperatures obtained from three experiments at no-load conditions with two different thermal and without thermal energy storage materials were 86.2, 91.3 and 80.3 C; and 67.8, 70.8 and 54 C respectively, at the corresponding maximum solar radiations of 716.5, 810 and 724.7 W/m. The recorded minimum drying chamber relative humidity of the solar dryer with TSMA, TSMB and without was 27, 24 and 23% respectively, and the corresponding ambient humidity was 70.8, 56.8 and 56.2%. A full load drying process using cocoa beans with TSMA took two full days, 10 hrs (58 hrs) to reduce initial moisture content of cocoa beans from 0.6 to 0.034 g water/g w.b. The maximum drying temperature and thermal efficiency obtained were 54 oC and 48.8% respectively. The dryer was thus viable for drying products within short time with little temperature control mechanism. RÉSUMÉ. Le but de cette étude était de concevoir et de fabriquer un séchoir solaire à convection forcée d’une capacité de 10 kg qui intègre aux matériaux de stockage thermique, TSMA et TSMB, en utilisant des matériaux locaux et à faible coût pour le séchage des produits agricoles. Le séchoir comprend principalement un capteur solaire bien isolé, une chambre de séchage et des composants photovoltaïques. Les températures maximales des capteurs et de la chambre de séchage sont obtenues de trois tests en conditions sans charge avec deux matériaux de stockage thermique différents et sans stockage thermique étaient de 86,2, 91,3 et 80,3 °C; et qui sont respectivement à 67,8, 70,8 et 54 °C aux radiations solaires maximales correspondantes de 716,5, 810 et 724,7 W / m. L'humidité relative minimale enregistrée de la chambre de séchage du séchoir solaire avec TSMA, TSMB et celle sans eux était respectivement de 27, 24 et 23%, et l'humidité ambiante correspondante était de 70,8, 56,8 et 56,2%. Un processus de séchage à pleine charge des grains de cacao avec du TSMA a pris deux jours complets, 10 heures (58 heures) pour réduire la teneur en humidité initiale des grains de cacao 24 ACSM. Volume 42 – n° 1/2018 de 0,6 à 0,034 g d’eau par gramme de poids corporel. La température maximale de séchage et l'efficacité thermique obtenues étaient respectivement de 54 °C et 48,8%. Le séchoir était viable pour sécher les produits en peu de temps avec peu de mécanisme de contrôle de la température.
本研究的目的是设计和制造一个10公斤容量的强制对流太阳能干燥器，集成了热能储存材料，TSMA和TSMB，使用本地采购和低成本的材料干燥农产品。该干燥器主要由绝缘良好的太阳能集热器、干燥室和光伏组件组成。采用两种不同蓄热材料和不采用蓄热材料的空载条件下，3个试验得到的集热器和干燥室最高温度分别为86.2、91.3和80.3℃;分别为67.8、70.8和54℃，对应的最大太阳辐射为716.5、810和724.7 W/m。有TSMA、TSMB和无TSMB的太阳能干燥机的最小干燥室相对湿度分别为27,24,23%，对应的环境湿度分别为70.8%，56.8%和56.2%。用TSMA对可可豆进行全负荷干燥，耗时2天10小时(58小时)，可将可可豆初始含水量从0.6 g水/g w.b降低至0.034 g水/g w.b，获得的最高干燥温度为54℃，热效率为48.8%。因此，在温度控制机制较少的情况下，该干燥机可以在短时间内对产品进行干燥。的简历。“但是，我们的数据显示，在过去的10年里，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示，我们的数据显示。”sassicchoir概述了“捕获太阳的原则”，即“sassicage和合成者”photovoltaïques。在没有电荷的条件下，在没有电荷的条件下，在没有储存热量的条件下，在没有储存热量的条件下，在86、2、91、3和80、3°C的条件下，在没有储存热量的条件下，在没有储存热量的条件下，在没有储存热量的条件下进行了三次试验;等温度分别为67、8、70、8和54°C，最大辐射量分别为716、5、810和724、7 W / m，相对最小辐射量分别为27,24和23%，等湿度分别为27,24和23%，等湿度分别为70,8、56、8和56,7 W / m。1个过程的ssamicacacsm - 2小时完成，10小时(58小时)的ssamicacacsm - 2小时的ssamicacacsm - 1小时的ssamicacacsm - 1小时内完成。第42卷- n°1/2018 de 0,6 00,034 g d 'eau par gramme de poids corporel。在54°C和48°C的温度下，温度与温度的比值分别达到了最大值和最大值。从目前的情况来看，从目前的情况来看，从目前的情况来看，从目前的情况来看，从目前的情况来看，从目前的情况来看，这是可行的。
{"title":"Design and fabrication of a forced convection solar dryer integrated with heat storage materials","authors":"Clement Adekunle Komolafe, M. A. Waheed","doi":"10.3166/ACSM.42.22-39","DOIUrl":"https://doi.org/10.3166/ACSM.42.22-39","url":null,"abstract":"The purpose of this study was to designed and fabricated a 10 kg capacity forced convection solar dryer integrated with thermal energy storage materials, TSMA and TSMB, using locally sourced and low-cost materials for drying agricultural products. The dryer consists mainly of a well-insulated solar collector, drying chamber and photovoltaic components. The maximum collector and drying chamber temperatures obtained from three experiments at no-load conditions with two different thermal and without thermal energy storage materials were 86.2, 91.3 and 80.3 C; and 67.8, 70.8 and 54 C respectively, at the corresponding maximum solar radiations of 716.5, 810 and 724.7 W/m. The recorded minimum drying chamber relative humidity of the solar dryer with TSMA, TSMB and without was 27, 24 and 23% respectively, and the corresponding ambient humidity was 70.8, 56.8 and 56.2%. A full load drying process using cocoa beans with TSMA took two full days, 10 hrs (58 hrs) to reduce initial moisture content of cocoa beans from 0.6 to 0.034 g water/g w.b. The maximum drying temperature and thermal efficiency obtained were 54 oC and 48.8% respectively. The dryer was thus viable for drying products within short time with little temperature control mechanism. RÉSUMÉ. Le but de cette étude était de concevoir et de fabriquer un séchoir solaire à convection forcée d’une capacité de 10 kg qui intègre aux matériaux de stockage thermique, TSMA et TSMB, en utilisant des matériaux locaux et à faible coût pour le séchage des produits agricoles. Le séchoir comprend principalement un capteur solaire bien isolé, une chambre de séchage et des composants photovoltaïques. Les températures maximales des capteurs et de la chambre de séchage sont obtenues de trois tests en conditions sans charge avec deux matériaux de stockage thermique différents et sans stockage thermique étaient de 86,2, 91,3 et 80,3 °C; et qui sont respectivement à 67,8, 70,8 et 54 °C aux radiations solaires maximales correspondantes de 716,5, 810 et 724,7 W / m. L'humidité relative minimale enregistrée de la chambre de séchage du séchoir solaire avec TSMA, TSMB et celle sans eux était respectivement de 27, 24 et 23%, et l'humidité ambiante correspondante était de 70,8, 56,8 et 56,2%. Un processus de séchage à pleine charge des grains de cacao avec du TSMA a pris deux jours complets, 10 heures (58 heures) pour réduire la teneur en humidité initiale des grains de cacao 24 ACSM. Volume 42 – n° 1/2018 de 0,6 à 0,034 g d’eau par gramme de poids corporel. La température maximale de séchage et l'efficacité thermique obtenues étaient respectivement de 54 °C et 48,8%. Le séchoir était viable pour sécher les produits en peu de temps avec peu de mécanisme de contrôle de la température.","PeriodicalId":7897,"journal":{"name":"Annales De Chimie-science Des Materiaux","volume":"49 1","pages":"22-39"},"PeriodicalIF":0.8,"publicationDate":"2018-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75149063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Maati, E. Ouakdi, L. Tabourot, P. Balland, M. Demouche
The main objective of this study is to propose a physics-based modelling adapted to describing the thermomechanical behaviour of metal alloys (specifically FCC metals). This approach takes into account the prominent phenomena generated by plastic deformation. Because of its specific mechanical and physical properties (ductility, lightness, etc.), this study is conducted on 1050 aluminium sheets widely used in sheet metal forming sector. The effect of two opposite and simultaneous physical phenomena on plastic deformation has been highlighted: the strain hardening rules that occurs because of dislocation movements and dislocation multiplication within the crystal structure of the metal and the dynamic recovery governed by thermal activation at intermediate temperatures (T≥0,4Tm). The evolution of two internal state variables (dislocation density and subgrain size) under different loading conditions was investigated. A Fortran program was used to identify the constitutive model parameters. To validate the present model, the curves obtained by numerical method were compared with those obtained by experimental traction data derived from literature. In a wide range of strain rates and temperatures, the obtained results show that the proposed model is effective in predicting the thermomechanical behaviour in traction for FCC metals due to the good agreement between calculated and experimental data. The results show that the strain hardening decrease significantly with increase in temperature and/or decrease in strain rate which explains dominance of dynamic recovery at elevated temperatures. Based on research conducted in the field, some proposals were introduced in the study to contribute to the improvement of numerical results and attempt to expand the use of the model for other types of loading (creep for example whose study is underway). RÉSUMÉ. L'objectif principal de cette étude est de proposer une modélisation phénoménologique à base physique adaptée à la description du comportement 116 ACSM. Volume 42 – n° 1/2018 thermomécanique des alliages métalliques (en particulier les métaux CFC). Cette approche prend en compte les phénomènes dominants générés au cours de la déformation plastique. En raison de ses propriétés mécaniques et physiques spécifiques (ductilité, légèreté, etc.), le métal retenu pour cette étude est l'aluminium 1050 utilisé souvent dans le secteur de mise en forme des tôles métalliques. L'effet de deux phénomènes physiques antagonistes et simultanés sur la déformation plastique a été mis en évidence : l'écrouissage qui est dû aux mouvements et multiplication des dislocations au sein de la structure cristalline du métal et la restauration dynamique gouvernée par l’activation thermique à des températures intermédiaires (T≥0,4Tf). L'évolution de deux variables internes (densité de dislocations et la taille de sous-grain) sous différentes conditions de sollicitation a été étudiée. Un programme Fortran a été utilisé pour identifier les
本研究的主要目的是提出一种基于物理的模型，适用于描述金属合金(特别是FCC金属)的热力学行为。这种方法考虑到塑性变形产生的突出现象。由于1050铝板具有特殊的机械和物理性能(延展性、轻质等)，本研究以广泛应用于钣金成型领域的1050铝板为研究对象。强调了两种相反且同时发生的物理现象对塑性变形的影响:由于金属晶体结构内的位错运动和位错增殖而发生的应变硬化规律以及在中间温度(T≥0,4 tm)下由热激活控制的动态恢复。研究了不同加载条件下两种内部状态变量(位错密度和亚晶粒尺寸)的演化规律。采用Fortran程序进行本构模型参数辨识。为了验证该模型的有效性，将数值方法得到的曲线与文献中导出的实验牵引数据得到的曲线进行了比较。在较宽的应变速率和温度范围内，计算结果与实验结果吻合较好，表明该模型能有效地预测FCC金属在牵引过程中的热力学行为。结果表明，随着温度的升高和应变速率的降低，应变硬化显著降低，说明高温下动态恢复占主导地位。在已有研究的基础上，本研究提出了一些建议，以改进数值结果，并尝试将该模型扩展到其他类型的荷载(例如正在进行研究的蠕变)。的简历。1 .设定目标原则，即设定目标，即设定目标，即设定目标，即设定目标，即设定目标。第42卷- n°1/2018 thermosamicanique des alliages msamtalliques(特别是les msamataux CFC)。这一方法旨在完成所有的物理上的、占主导地位的、由可变的和可变的过程构成的物理上的和可变的。En雷森de ses proprietes机械等体型specifiques (ductilite, legerete等等),勒金属克制倒在练习曲l 'aluminium 1050利用可是在secteur de协定身材的话des托霜花。L'effet de deux phacomomnes physiques antagonistes et simultaneous samas sur la samacimous plastique a samacess en samuence: 1 ' samacomisage qui est dû aux运动和增殖des dislocations au sein de la structure crystaldu samactal et la resresdynamicment government ' activation thermique ones des temtemsamatres intermsamdiaires (T≥0,4 tf)。两个变量间的交换(密度、错位和小颗粒的交换)、不同的交换条件、不同的交换条件和不同的交换条件。联合国程序Fortran的一个实用程序，为标识符的参数和模块构成。为了验证模型的有效性，我们可以使用下列方法来获得相同的数据:1 .使用相同的数据;2 .使用相同的数据;3 .使用相同的数据;3 .使用相同的数据;在一个大的游戏中，从时间和性质的角度出发，从时间和性质的角度出发，从时间和性质的角度出发，从时间和性质的角度出发，从时间和性质的角度出发，从时间和性质的角度出发，从时间和性质的角度出发，从时间和性质的角度出发，从时间和性质的角度出发，从时间和性质的角度出发。由于“暂时的”和“暂时的”的增加，“暂时的”和“暂时的”的减少，“暂时的”和“动态的”的减少，“暂时的”和“动态的”都是“暂时的”和“动态的”。根据关于交换交换和交换交换条件的基本原则，关于交换交换和交换交换条件的建议介绍了交换交换和交换交换条件下的交换交换和交换交换条件下的交换交换(例如，交换交换条件下的交换交换)。
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This paper attempts to make an accurate assessment of the safety and stability of tunnels in blasting excavation, considering the effect of rock mass intactness. For this purpose, numerical simulations and field tests of tunnel blasting excavations were carried out in rocks with different intactness indexes. For simplicity, the multi-hole blasting load was replaced with the equivalent blasting load according to the Chapman-Jouguet (C-J) detonation mechanism and the theory of stress wave propagation in elastic medium. Then, the existing blasting damage model of rock mass was improved into a continuum damage model of rock blasting considering the intactness of rock mass, and imported to FLAC3D for numerical simulations of tunnel blasting excavation. The simulation results were then verified through field tests on blasting vibration velocity and acoustic wave velocity. The attenuation law of blasting vibration was obtained from the tests on blasting vibration velocity, while the blasting-induced fracture zone was determined through the tests on acoustic wave velocity in the borehole before and after blasting. The blasting-induced fracture zone near the explosion sources and the attenuation law of blasting vibration velocity far from the sources were both identified in the numerical simulations and the field tests. After that, the results of the numerical simulations were compared with those of the field tests. The comparison shows that: after the blasting excavation of pressure diversion tunnels, the maximum and the minimum depths of blasting-induced fracture in the surrounding rock respectively appeared at the haunch and the vault of tunnels; when the drilling and blasting parameters remained constant, the maximum depth of blastinginduced fracture and several other factors decreased significantly with the growth of the intactness index; meanwhile, the vibration-influenced distance of blasting increased first and then decreased. The results of numerical simulations agree well with those of the field tests. The research findings provide valuable guidance to blasting excavation of pressure diversion tunnels. RÉSUMÉ. Dans le contexte de l’excavation par dynamitage de tunnels de dérivation de pression dans la centrale hydroélectrique Xi Luodu en Chine, le but de cette étude, c’est de fournir des références à l’évaluation de la sécurité et de la stabilité du tunnel pendant les excavations, à laquelle l’influence de la masse rocheuse devrait être considérée. Pour atteindre ce but, des simulations numériques et des essais sur le terrain d'excavations par soufflage dans des tunnels 76 ACSM. Volume 42 – n° 1/2018 ont été effectués dans les roches avec des indices d'intégrité différents. Visant à simplifier la simulation numérique du dynamitage à trous multiples, une méthode d'utilisation de charges de dynamitage équivalentes pour remplacer la charge de dynamitage à trous multiples a été présentée, selon le mécanisme de donation C-J et la théorie de la propag
本文试图在考虑岩体完整性影响的情况下，对爆破开挖隧道的安全性和稳定性进行准确的评价。为此，在不同完整性指标的岩石中进行了隧道爆破开挖的数值模拟和现场试验。为简便起见，根据Chapman-Jouguet (C-J)爆轰机理和弹性介质中应力波传播理论，将多孔爆破荷载替换为等效爆破荷载。然后，将现有岩体爆破损伤模型改进为考虑岩体完整性的岩体爆破连续损伤模型，导入FLAC3D中进行隧道爆破开挖数值模拟。通过爆破振动速度和声波速度的现场试验验证了模拟结果。通过爆破振动速度试验得到了爆破振动的衰减规律，通过爆破前后孔内声波速度试验确定了爆破致裂区。通过数值模拟和现场试验，确定了爆炸震源附近的爆致破裂带和远离震源的爆破振动速度衰减规律。并将数值模拟结果与现场试验结果进行了比较。对比结果表明:压力导流隧洞爆破开挖后，围岩爆致裂隙的最大深度和最小深度分别出现在隧洞后腰和拱顶处;在钻爆参数一定的情况下，随着完整性指数的增大，最大爆破致裂深度和其他几个因素显著减小;同时，爆破振动影响距离先增大后减小。数值模拟结果与现场试验结果吻合较好。研究结果对压力导流隧洞爆破开挖具有一定的指导意义。的简历。[cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn] [cn]] [cn] [cn] [cn] [cn]]在此基础上，模拟了隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖等。卷42 - n°1/2018安大略省的高频effectues在罗氏用des指数d 'integrite不同。Visant简化器为模拟虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机，使用虚拟机。如果一个模数没有改变，那么这个模数就没有改变。如果一个模数没有改变，那么这个模数就没有改变，那么这个模数就没有改变。模数转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器转换器。地形的性质决定了振动的性质决定了动力的性质决定了声学的性质决定了模拟的性质决定了效果的性质决定了模拟的性质决定了模拟的性质。Les essais de vitesse des ondes acousticques ont samest - effective - samest - dans - free - avant - apres - free - dynamicage - free - free - free - free - free - free - free。没有测试，没有动力，没有振动，没有动力，没有动力，没有动力，没有动力，没有动力，没有动力。模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟，模拟模拟在模拟的过程中，在模拟的过程中，在模拟的过程中，在模拟的过程中，在模拟的过程中，在模拟的过程中，在模拟的过程中，在模拟的过程中，在模拟的过程中，在模拟的过程中。隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖、隧道开挖。Dans les conditions où les parametric treres de牧草和动力常数，la profondeur maximale de fracture indute动力常数，ainsi que le coefficient d 'influence du site et l ' attacimatement de la formula de Sadaovsk qui perme de pracimadela vitesse maximale impact same par vibration，减小了牧草和显著平均值，增加了牧草和动力指数。 受振动影响的爆破距离先增大，然后随着完整性指数的增加而减小。数值模拟结果与现场试验结果吻合较好。研究结果为西罗度水电站旁路隧道爆破开挖提供了指导。
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