检索结果-内蒙古大学图书馆

GREEN QUASIFUNCTION METHOD FOR FREE VIBRATION OF SIMPLY-SUPPORTED TRAPEZOIDAL SHALLOW SPHERICAL SHELL ON WINKLER FOUNDATION

引用

Acta Mechanica Solida Sinica 2010年第4期23卷 370-376页

作者： Shanqing Li Hong Yuan (MOE key laboratory of disaster forecast and control in engineering, Institute of Applied Mechanics, Jinan University, Guangzhou 510632, China) [a] MOE Key Laboratory of Disaster Forecast Control in Engineering Institute of Applied Mechanics Jinan University Guangzhou 510632 China

The idea of Green quasifunction method is clarified in detail by considering a free vibration problem of simply-supported trapezoidal shallow spherical shell on Winkler foundation.A Green quasifunction is established by using the fundamental solution and boundary equation of the *** function satisfies the homogeneous boundary condition of the *** mode shape differential equation of the free vibration problem of simply-supported trapezoidal shallow spherical shell on Winkler foundation is reduced to two simultaneous Fredholm integral equations of the second kind by Green *** are multiple choices for the normalized boundary *** on a chosen normalized boundary equation, the irregularity of the kernel of integral equations is ***, natural frequency is obtained by the condition that there exists a nontrivial solution in the numerically discrete algebraic equations derived from the integral *** results show high accuracy of the Green quasifunction method.

关键词： Green function integral equation shallow spherical shell free vibration Winkler foundation

来源：评论

学校读者我要写书评

暂无评论

Analysis of Characteristics of Compound Vibration and Effects to Surrounding Gas Pipeline Caused by Impact and Explosion

引用

Procedia engineering 2011年 26卷 1835-1843页

作者： Su Hua-you Huang Jin Xiao Ding-jun She Yan-hua College of Environment and Resource Southwest University of Science and Technology Mianyang 621010 China Key Lab. for the Exploitation of Southwestern Resources & the Environmental Disaster Control Engineering Ministry of Education in China Chongqing 40044 China

The vibration load caused by the impact and explosion in construction exerts great influence on the surrounding earth. Therefore, the safe operating condition of gas pipeline is seriously influenced. For the first time, by use of smart microseismic monitoring system, such vibration caused by the impact and explosion is monitored and analyzed. First, it reveals the transmission law of vibrating wave forms. Second, the coupling calculating models of pipeline earth under the influence of vibration is built. Finally, the characteristics of exerted force and transformation of earth-pipeline system are analyzed. According to these microseismic data obtained from the spot and numerical simulation method, the dynamic response of underground pipeline under compound vibration is studied; nonlinear mathematical model theory and method for coupling effects of earth and pipeline are built; the effects of vibration to pipeline are assessed; the feasible assessing method of safe operating condition of gas pipeline under vibration is explored and developed.

关键词： vibration load microseismic monitoring blasting gas pipeline

来源：评论

学校读者我要写书评

暂无评论

Analytical Solution of the Thermoelasticity Problem in a Coke Drum With Cladding

引用

JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME 2011年第3期133卷 31201-31201页

作者： Ning, Z. H. Liu, R. H. Huang, S. Q. Lu, X. S. Jinan Univ Minist Educ Peoples Republ China Key Lab Disaster Forecast & Control Engn Guangzhou 510632 Guangdong Peoples R China Jinan Univ Inst Appl Mech Guangzhou 510632 Guangdong Peoples R China Jinan Univ Dept Mech & Civil Engn Guangzhou 510632 Guangdong Peoples R China

Craze cracking and clad disbonding typically occur in cladding due to thermomechanical cycling and high property mismatch between dissimilar materials in a coke drum. The thermoelasticity problem in a coke drum with cladding is assumed quasi-static and solved analytically in this paper. The transient temperature distribution in both radial and axial directions is derived analytically based on the two-dimensional heat conduction theory. The iteration technique is applied to simulate the dynamic thermal boundary conditions caused by a fluid surface level rising continuously during both heated feed filling and water quench steps. Additionally, the classical laminated thin shell theory is applied to solve the quasi-static structural problem. The analytical results of the quasi-static thermoelasticity problem are compared with the finite element analysis. It is shown that during the water quench step, the maximum axial thermal gradient occurs at the inner surface of the clad, close to the water surface. The tension stresses occur in the clad due to its coefficient of thermal expansion smaller than that of the base metal material. Both the maximal axial stress and hoop stress occur at the cladding surface. These results may be helpful in explaining the formation mechanism of the clad disbonding and the shallow surface cracks at the inner surface of cladding. [DOI: 10.1115/1.4002625]

关键词： thermoelasticity coke drum analytical solution cylindrical shell thermal transient cladding

来源：评论

学校读者我要写书评

暂无评论

Numerical simulation and model test study of mechanismof bolt in deep tunnel

引用

Yantu Lixue/Rock and Soil Mechanics 2011年第SUPPL. 1期32卷 719-724+786页

作者： Chen, Hao Ren, Wei-Zhong Li, Dan Xia, Bin-Wei State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China College of Urban Construction Wuhan University of Science and Technology Wuhan 430065 China Key Lab. for Exploitation of Southwestern Resources and Environmental Disaster Control Engineering Chongqing University Chongqing 400030 China

According to rock character of a certain soft rock tunnel of Chongqing, the model material is made from epoxy resin, polyamide, silicom rubber, firming agent of silicon rubber, quartz grit, powdery barite and gasoline. The physical model test of the unreinforced tunnel and bolt-reinforced tunnel are made in the true triaxial model test machine. By using strain measure technology, the strains of key parts of the surrounding rock and the bolt are measured;according to these data, the variability of the stress of surrounding rock and the variability of the axial force of the bolt are analyzed. The numerical simulation are made with the same boundary condition as the model test;according to these data, the plastic zone, stress field and the deformation of the surrounding rock are studied;the variation of the axial force of the bolt is studied. We compare the variation of stress of the surrounding rock and the variation of the axial force of the bolt of the model test with the numerical simulation and draw the conclusion that the two processes coincide with each other.

关键词： Numerical models

来源：评论

学校读者我要写书评

暂无评论

Experimental Study of Different Gases on Permeability of Tectonic Coal

引用

Procedia engineering 2011年 26卷 1176-1183页

作者： Lei Meng Yaodong Jiang Jie Zhu Ang Li Weizhong Wang China University of Mining & Technology Beijing 100083 China State Key Lab of Coal Resources and Safe Mining Beijing 100083 China Key Laboratory for the Exploitation of Southwest Resources and Environmental Disaster Control Engineering Ministry of Education Chongqing University Chongqing 400044 China

In order to investigate the change law of different gas permeability of tectonic coal under circumstances of different gas pressure and different stress condition, take the tectonic coal with low permeability and outburst hazard as research object and study on the different gas permeability change law of tectonic coal in complete stress-strain process by using the triaxial servo-controlled seepage equipment for thermo-fluid-solid coupling of coal containing gas. The experimental results show that the complete stress-strain curve of coal containing methane is similar to that of coal containing carbon dioxide, which can be divided into five stages with unique characteristics respectively, and there are the minimum value of permeability corresponding to the neighboring juncture between stage II and phase III in complete stress-strain process. In addition, there are existing Klinkenberg effects not only for absorbing gas, such as methane and carbon dioxide but also for non-absorbing gas such as helium gas in the gas-bearing coal seam. Moreover, the Klinkenberg effect on the methane permeability of coal exists in all the stress condition of coal in complete stress-strain process and that on carbon dioxide permeability of coal only appears in the coal compaction named by phase I. Therefore, occurrence of Klinkenberg effect have something to do with structure of coal mass, but also are related to gas type and stress condition of coal mass.

关键词： Permeability Tectonic Coal methane Carbon dioxide Klinkenberg effect

来源：评论

学校读者我要写书评

暂无评论

Study on Pre-splitting Blasting to Improve Permeability Drainage Rate in Heading Excavation

Study on Pre-splitting Blasting to Improve Permeability Drai...

引用

2011全国特殊气藏开发技术研讨会

作者： Wang Hong-tu Fan Xiao-gang Yuan Zhi-gang Xu Hou-xue State and local joint engineering laboratory of methane drainage in complex coal gas seam Chongqing Key Lab for Exploitation of China Southwestern Resources & Environmental Disaster Control Engineerin

Aim at the problem of low excavation speed and high risk of coal and gas outburst because of low gas draining rate in heading excavation, taking an excavation heading of a mine for example, the test of deep-hole pre-splitting blasting was *** amount of gas draining after pre-splitting was compared to the amount of direct draining, and the effective radius of draining was *** test result showed that the draining rate of K1 coal seam reached 37.13%, which reduced the draining time by 60%, 10 days after pre-splitting, and the gas desorption index exceed the standards until the fifth *** draining rate of K4 needed 12 days to reach 34.28%, which reduced the draining time by 60%, and the gas desorption index exceed the standards when the third blasting ***, the effect of gas draining was improved by pre-splitting *** effective draining radius of K1 and K4 were 4.5 m and 5.2 m respectively after pre-splitting blasting.

关键词： coal mine,heading excavation pre-splitting blasting draining radius

来源：评论

学校读者我要写书评

暂无评论

Evaluation indexes of sand liquefaction analysed by rough set

引用

1st International Conference on Civil engineering, Architecture and Building Materials, CEABM 2011

作者： Liu, Nianping Wang, Hongtu Yuan, Zhigang Key Lab. for Exploitation of China Southwestern Resources and Environmental Disaster Control Eng. Chongqing University Ministry of Education Chongqing 400030 China State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam Chongqing University Chongqing 400030 China College of Environment and Resources Southwest University of Science and Technology Mianyang 621010 China

ISBN: (纸本)9783037851258

Sand liquefaction is a problem of complex evolution of the disaster, there is no accurate way to judge at present, this study put forward an analytical method to improve and optimize the evaluation system of sand liquefaction based on rough set. The significance of indexes are confirmed by calculating rough dependability between indexes and result for appraisement, the result show that SPT blow count has the greatest impact on the evaluation system, the groundwater level has greater impact, followed by the sand depth, epicenteral distance and duration. The proposed approach overcame the subjectivity of traditional weight determination method, so it is more objective and accurate, and it is reasonable and effective to optimize the evaluation index of sand liquefaction. © (2011) Trans Tech Publications.

关键词： Groundwater

来源：评论

学校读者我要写书评

暂无评论

Analysis of transient temperature field in coke drums

引用

Applied Mathematics and Mechanics(English Edition) 2010年第3期31卷 291-304页

作者：宁志华刘人怀 Key Laboratory of Disaster Forecast and Control in Engineering Ministry of Education of ChinaJinan University Institute of Applied Mechanics and Department of Mechanics and Civil Engineering Jinan University

One of the primary reasons leading to bulging and cracking in a coke drum is the severe temperature gradient due to cyclic temperature variation. Based on the twodimensional heat conduction theory, an analytical solution of the transient temperature field in the coke drum is obtained, which is different from the known FEM results. The length of the coke drum is considered finite. The dynamic boundary conditions caused by fluid uninterrupted rising in oiling and watering stages are simulated with the iteration method. Numerical results show that the present theoretical model can accurately describe basic features of the transient temperature field in the coke drum. Effects of the geometry of the coke drum and the rising velocity of quench water on the axial temperature gradient are also discussed.

关键词： coke drum cylindrical shell transient temperature field temperature gradient

来源：评论

学校读者我要写书评

暂无评论

引用

2011 2nd International Conference on Mechanic Automation and control engineering, MACE 2011

作者： Li, Xiaoshuang Li, Yaoji Yin, Guangzhi He, Lin National Engineering Research Center of Phosphate Resources Development and Utilization Chongqing University Chongqing 400030 China State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam Chongqing University Chongqing 400030 China Key Lab. for the Rsrc. Exploitation and the Environ. Disaster Control Engineering in Southwest China State Ministry of Education Chongqing University Chongqing 400030 China Yunnan Phosphate Chemical Group Co. LTD. Jinning 650600 China

ISBN: (纸本)9781424494392

Based on the gently inclined medium thick phosphate rock of the deep part of the east mining section of +2150 level of Jinning-Six mine of Yunnan phosphate Co., Ltd, the similar material physical model simulation experiment of the stability of stope pillars under room and pillar mining was carried out by the mine pressure plane stress modeling experimental frame of college of resource and environmental sciences. Based on the experimental results,the deformation and failure changing law of the above roof, surrounding rock mass and stope pillar during the mining along the strike direction of phosphate were investigated. The experimental results showed: (1) With the increasing of the scope of mined-out area, the fwassure zone and separation layer zone of the roof in the original mined-out area of the stope were pressed compact step by step. And when the space range of the mined-out area reached some scale, the deformation of the fwassure zone and separation layer zone of the roof in the original mined-out drived to stabilwasation, and the sustain action of it to the gravity fore of the overlying strata was reexternalization. (2)After the mining, the subsidence region of the overlying strata of the stope mainly concentrated the roof and surrounding rock mass which beside the mined-out area, the position of the maximum subsidence point was in the center zone of the excavation space, with the increasing of the dwastance from the center of the stope along the trend and normal of the ore body, the subsidence value of the overlying strata of the stope was monotone decreasing. With the increasing of the region of the excavation space, the mining influence region and the mining inflence degree of the overlaying strata of the stope gradually increased. And the corresponding position of the maximum subsidence zone dynamically forward leaded, the final subsidence curve of the overlying strata was a bowl shaped curve. (3)The defoemation and failure characterwastics of the overlyin

关键词： Room and pillar mining

来源：评论

学校读者我要写书评

暂无评论

Contribution of safety to economic growth: A case study of China mining industry

Contribution of safety to economic growth: A case study of C...

引用

Chinese control and Decision Conference

作者： Haixia, Tan Hongtu, Wang Zaiqing, Wang Lin, Chen Huanlin, Ren Key Lab for Exploitation of China Southwestern Rsrc. and Environmental Disaster Control Engineering Ministry of Education Chongqing University Chongqing 400030 China Institute of Chongqing Geology and Mineral Resources Chongqing 400030 China Exploration Institute of Geology and Mineral Resources Yunnan Bureau of Geology and Mineral Resources Kunming 650051 China College of History and Sociology Huaibei Normal University Huaibei 235000 China

ISBN: (纸本)9781424487363

Safety input is a way of safeguarding mining, as well as one of main reasons for the increased growth rates of Total Factor Productivity (TFP). To figure out the contribution of the safety input to mining economic growth, a new production safety index system with six principal items describing China mining safety was constructed. The study found that China mining production safety level was improved continuously, a more than 17-fold increase from 1991 to 2008. Using co-integration theory and dynamic construction model, a mining economic growth model was established based on the new production safety index system. The empirical results prove that labor input and capital input are still major factors of promoting mining economic growth, and the production safety not only contributed the short-term GDP growth of mining industry but also helped present 8.8% of contribution rate to the long-term elasticity coefficient. © 2011 IEEE.

关键词： Accident prevention

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：