检索结果-内蒙古大学图书馆

Investigation on the reinforcement effect of a bedding slope affected by a landsliding block

Arabian Journal of Geosciences 2022年第6期15卷 1-20页

作者： Zhang, Fei Yang, Tianhong Li, Lianchong Zhu, Xinping Key Laboratory of Roads and Railway Engineering Safety Control Shijiazhuang Tiedao University Ministry of Education Shijiazhuang China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang China Center of Rock Instability and Seismicity Research School of Resources and Civil Engineering Northeastern University Shenyang Liaoning China China Coal Technology and Engineering Group Shenyang Research Institute Fushun China

The south slope of Fushun west open-pit mine located in Northeast china is a high-deep rock slope. In the last few years, a landsliding block has gradually formed in the south slope. Owing to the effect of sliding force caused by the sliding block, some damage has occurred on the foundation of Kengkou refinery which constructed in the west of the south slope. To improve the stability of the refinery foundation, three group micro-pile structures were employed to cut off the drag of the sliding block and reinforce the refinery on the southwest slope. In this study, a comprehensive method combining the microseismic monitoring technique and numerical simulation method was used, the stability of the southwest slope was evaluated, and reinforcement mechanism was deeply analyzed. A microseismic monitoring system is established on-site to obtain useful information about the damage energy, location, and magnitude of the rocks in the southwest slope. Thus, the west boundary of the landslide in the south slope of the open-pit is determined. By analyzing the numerical results, the stress concentration is discovered mainly around the micro-pile structures and near the west boundary. After reinforcement, the displacement decrease in the south-north direction is apparent. To investigate the interaction mechanism between the micro-pile and the surrounding rock mass, a local 3D numerical model is employed to help understand auxiliary information about the stress state and stress redistribution induced by failure in the surrounding rock mass. It is shown that the reinforcement effect becomes more and more evident with the increase in the number of employed micro-piles. The numerical results and in situ GPS displacement monitoring data illustrate that the micro-pile structures have an excellent strengthening result in controlling the deformation of the slope. The comprehensive methodology provides an effective way to estimate the stability and the reinforcement effect of the slope und

关键词：

来源：评论

学校读者我要写书评

暂无评论

Invariant cubature kalman filter for monocular visual inertial odometry with line features

arXiv

引用

arXiv 2019年

作者： Deli, Y.A.N. chunhui, W.U. Wang, Weiming Song, Yu Li, Shaohua State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China School of Electrical and Electronic Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China School of Electronic and Information Engineering Beijing Jiaotong University Beijing100044 China

To achieve robust and accurate state estimation for robot navigation, we propose a novel Visual Inertial Odometry(VIO) algorithm with line features upon the theory of invariant Kalman filtering and cubature Kalman Filter (cKF). In contrast with conventional cKF, the state of the filter is constructed by a high dimensional Matrix Lie group and the uncertainty is represented using Lie algebra. To improve the robustness of system in challenging scenes, e.g. low-texture or illumination changing environments, line features are brought into the state variable. In the proposed algorithm, exponential mapping of Lie algebra is used to construct the cubature points and the re-projection errors of lines are built as observation function for updating the state. This method accurately describes the system uncertainty in rotation and reduces the linearization error of system, which extends traditional cKF from Euclidean space to manifold. It not only inherits the advantages of invariant filtering in consistency, but also avoids the complex Jacobian calculation of high-dimensional matrix. To demonstrate the effectiveness of the proposed algorithm, we compare it with the state-of-the-art filtering-based VIO algorithms on Euroc datasets. And the results show that the proposed algorithm is effective in improving accuracy and robustness of estimation. copyright © 2019, The Authors. All rights reserved.

关键词： Kalman filters

来源：评论

学校读者我要写书评

暂无评论

Indentation Responses of Piezoelectric Semiconductors

SSRN

引用

SSRN 2023年

作者： Liu, Jinxi Gao, Shijing Zhang, Zeran Nie, Guoquan chen, Weiqiu State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China Department of Engineering Mechanics Hebei Key Laboratory for Mechanics of Intelligent Materials and Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Key Lab of CAD & CG Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Department of Engineering Mechanics Zhejiang University Hangzhou310027 China

In this paper, the indentation responses of a piezoelectric semiconductor (PSc) half-space by an insulating and rigid spherical indenter are investigated. It is assumed that the contact area between the indenter and the PSc is frictionless. Based on the Hankel integral transformation, the considered indentation problem is reduced to a pair of dual integral equations. Due to the complexity of the coupled governing differential equations, the explicit closed-form expressions for the PSc indentation responses cannot be derived like the piezoelectric counterparts. Therefore, the dual integral equations are converted into the Fredholm integral equation of the second kind, which is numerically solved to determine the concerned responses. These responses include the relationships of the indentation force, the electric potential and the change of carrier concentration with the indentation depth. The numerical results show that the semiconducting property has a significant influence on the indentation characteristics. In addition, the three-dimensional finite element simulations are carried out to validate the theoretical results computed by the singular integral equation method. It turns out that the two results are well consistent. The distributions of the stress and electric potential near the contact area are simulated by finite element method to reveal the effect of the steady carrier concentration. The obtained findings are useful for understanding the interaction between piezoelectricity and semiconducting property. © 2023, The Authors. All rights reserved.

关键词： Indentation

来源：评论

学校读者我要写书评

暂无评论

Design and Analysis of the cooling Effect of the Temperature-controlled Pile (Tcp) in Permafrost Regions

SSRN

引用

SSRN 2022年

作者： Sun, Zhaohui Liu, Jiankun Hu, Tianfei You, Tian Fang, Jianhong School of Civil Engineering Sun Yat-sen University Southern Marine Science and Engineering Guangdong Laboratory Zhuhai519082 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Qinghai Research Institute of Transportation Xining810001 China

To accelerate the refreezing time of cast-in-place piles in permafrost regions and improve their long-term stability, this paper proposes a novel TcP based on solar refrigeration. The TcP consists of a solar power system (SPS), a vapor compression refrigeration system (VcRS), and a pile. Then, the cooling effect of TcP was carried out by the model test and the numerical simulation. The model test results show that both the evaporating temperature and the condensing temperature are positively correlated with the ambient temperature, but the coefficient of performance (cOP) is negatively correlated with the ambient temperature. The numerical simulation results show the TcP can significantly shorten the refreezing time. The higher the mean annual ground temperature (MGAT), the more significant the acceleration effect. With the increase in the TcP working time, the pile wall permafrost temperature tends to be stable, and the cooling radius increases continuously. The TcP can restrain the degradation rate of the permafrost table, which can be further reduced by increasing the refrigeration power and the refrigeration tube space. The tangential freezing force between the frozen soil and the pile foundation is enhanced by the cooling effect of TcP and is stronger when it is close to the middle of the pile. The TcP bearing capacity is more than 1.5 times that of a traditional pile (TP). The effect of improving the bearing capacity of the pile foundation can be achieved by increasing the refrigeration power and refrigeration tube space. Therefore, TcP can be applied to pile engineering of high-speed railways and highways in permafrost regions. © 2022, The Authors. All rights reserved.

关键词： Piles

来源：评论

学校读者我要写书评

暂无评论

Influence of External Structure and Internal Stacking on Wind Load characteristics of Large Span Spherical Shell Structure

SSRN

引用

SSRN 2023年

作者： Liu, Xiaobing chen, Anjie Yang, Qun Feng, Bin Tian, Xuedong State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Innovation Center for Wind Engineering and Wind Energy Technology of Hebei Province Shijiazhuang050043 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China

In order to study the wind load characteristics of the large span spherical shell structure, a rigid model pressure test was conducted in a wind tunnel laboratory to study the effects of different external structures and internal stacking forms on wind loads of a spherical shell structure in an actual project. The variation laws of the shape factor and the integral force coefficient of the spherical shell structure under different test cases are compared and analyzed. The results show that the shape factor of the spherical shell structure is only affected near the interference when the transfer station and trestle are arranged. When the two spherical shell structures are arranged in series and the adjacent spherical shell structure is located upstream, the shape factor of the spherical shell structure is most affected, and there is a significant reduction effect at the bottom of the windward surface. compared with the external structure, the influence of different internal stacking forms on the shape factor of the spherical shell structure is relatively weak. The interference effect of the adjacent spherical shell structure makes the stress situation of the spherical shell structure better than that of the spherical shell structure without the adjacent spherical shell structure in most wind directions. The integral force coefficient of the spherical shell structure is the highest when the internal stacking is full, and the lowest when there is no internal stacking. Therefore, the integral force coefficient of the spherical shell structure when the internal stacking is full can be used as a reference for the design of the frame of the spherical shell structure. © 2023, The Authors. All rights reserved.

关键词： Shells (structures)

来源：评论

学校读者我要写书评

暂无评论

Experimental Study on Fluctuating Aerodynamic Force and Wind Pressure Distribution characteristics of Three circular cylinders Arranged Inline

SSRN

引用

SSRN 2023年

作者： Liu, Xiaobing Jiang, Huimin Wang, Shibo Liu, Xiqiang Yang, Qun State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Innovation Center for Wind Engineering and Wind Energy Technology of Hebei Province Shijiazhuang050043 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China

The fluctuating aerodynamic force and wind pressure distribution characteristics of three circular cylinders arranged inline at different incidence angles and spacing ratios were studied via rigid model pressure measurement wind tunnel tests. The results were compared with those of a single cylinder. The Reynolds number is 6.4×104. The range of incidence angle α and spacing ratio L/D (the ratio of the center distance between adjacent cylinders to the diameter of the cylinder) are 0°~90° and 1.2~4.0, respectively. The spacing ratio and incidence angle greatly influence the fluctuating aerodynamic force coefficients and wind pressure coefficients. According to the spacing ratio, the fluctuating aerodynamic characteristics can be roughly divided into three states: small spacing ratios (1.2≤L/D≤2.0), medium spacing ratios (2.0 © 2023, The Authors. All rights reserved.

关键词： circular cylinders

来源：评论

学校读者我要写书评

暂无评论

Experimental Study on Shear Strength characteristics of Frozen Soil - cast-in-Situ concrete Interface

SSRN

引用

SSRN 2022年

作者： Sun, Tiecheng Dong, chuangqi Zhang, Jiao Zong, Zihang Wu, Kai State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Key Laboratory of Roads and Railway Engineering Safety Control Ministry of Education Shijiazhuang050043 China Hebei Province Technology and Innovation Center on Intelligent Construction of Infrastructure Shijiazhuang050043 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China

The roughness of contact surface is closely related to the friction coefficient and shear strength characteristics of pile-soil interface. At present, there is no recognized and unified quantitative characterization method of contact surface roughness. In this paper, the roughness formula is corrected in combination with the proposed form factor, and the low temperature direct shear test of the frozen soil-cast-in-situ concrete interface is carried out. The influence of several test factors, such as contact surface roughness, normal pressure and moisture content of soil sample, on frozen shear strength of frozen soil-cast-in-situ concrete contact surface is analyzed. The test results show that: (a) The frozen shear strength at the contact surface is mainly determined by the cementation of ice cementation force, cohesion and the bite force between frozen soil and concrete. The roughness corrected by the form coefficient can accurately characterize the contribution of bite force to the frozen shear strength of the contact surface. (b) The primary and secondary order of the influence of test control factors on the frozen shear strength of contact surface is normal pressure > moisture content of soil sample > test temperature > roughness > dry density. The normal pressure and moisture content have a strong and significant influence on the test results, the influence of dry density is not significant, and the influence of test temperature and roughness is in the middle. (c) The frozen shear strength of the contact surface increases with the increase of roughness, but the increase of normal pressure can weaken the effect of roughness on the enhancement of shear strength. © 2022, The Authors. All rights reserved.

关键词： Temperature

来源：评论

学校读者我要写书评

暂无评论

Solar Energy-Based Active Heating Method for Frost-Resistant Embankments: A case Study in china

SSRN

引用

SSRN 2022年

作者： Hu, Tianfei Sun, Tiecheng Wang, Tengfei Zhang, Zongkai Wang, Li State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University 17 Northeast Second Inner Ring Hebei Province Shijiazhuang050043 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China MOE Key Laboratory of High-Speed Railway Engineering Southwest Jiaotong University Chengdu610031 China

The primary objective of this study is to address embankment frost heave issues in cold regions with an active heating method. A real-time and efficient method of solar heating is developed based on the concept of actively controlling the balance between heat absorption and heat loss. The applicability of various heat sources was compared with the heating demands of embankment. The case study demonstrates that the seasonally frozen areas of china are rich in solar energy resources. A dedicated embankment heating device was designed, including a solar collector section and an embankment heater section. The device integrates energy conversion, storage, and transfer without any moving part, and thus can be used in an "isolated island" scenario for self-driven operations. Performance tests showed that the maximum heating temperature exceeds 60 °c, with an average range of 20–40 °c, which increases with solar radiation. The effective heat utilization rate of soil is approximately 26%. A predictive model that considers latitude and daily ordinal number was proposed for heating temperature. A numerical simulation of the actual embankment long-term heating performance was performed. The results revealed that the heating mode in all seasons could effectively enhance the potential of frost-resistant embankments in winter. © 2022, The Authors. All rights reserved.

关键词： Solar energy

来源：评论

学校读者我要写书评

暂无评论

Wheelset Bearing Fault Diagnosis Method Based on a Novel Parameter-Adaptive Vmd

SSRN

引用

SSRN 2022年

作者： Li, cuixing Liu, Yongqiang Liao, Yingying State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China School of Traffic and Transportation Shijiazhuang Tiedao University Shijiazhuang050043 China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China

The traditional parameter-adaptive VMD method uses an advanced meta-heuristic algorithm to determine the two key parameters of mode number and penalty factor adaptively, but this method has the deficiency of a long time-consuming. To solve this problem, a novel parameter-adaptive VMD method is proposed in this paper, which uses the PSO to optimize the initial center frequency and the penalty factor. The single-mode VMD has a strong convergence and can converge to the optimal center frequency as long as the initial center frequency is in the U-shaped range. With this characteristic of VMD, we propose an improved PSO. The correctness of the proposed method is verified by analyzing the fault signals of two sets of wheelset bearings. compared with the traditional parameter-adaptive VMD method and the EEMD method, the results show that the proposed method has outstanding advantages in fault feature extraction and operation efficiency. © 2022, The Authors. All rights reserved.

关键词： Failure analysis

来源：评论

学校读者我要写书评

暂无评论

Effects of the cuo Additive Nanoparticles on the Internal Strain Homogenization and Microstructure Evolution in Ag-Sno2 composites

SSRN

引用

SSRN 2022年

作者： Li, Guijing Ma, Yuanyuan Feng, Wenjie Zhang, chuanzeng Yan, Zhen Fang, Xueqian Tian, Ruilan Shijiazhuang Tiedao University Shijiazhuang050043 China Provincial Collaborative Innovation Center of Mechanics of Intelligent Materials Hebei China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures China Department of Civil Engineering University of Siegen SiegenD-57068 Germany Department of Engineering Mechanics Germany

Stress concentration caused by reinforcements has very unfavorable effects on the metal matrix composites, which will inevitably induce localized strains and crack initiation. In this paper, an effective approach is presented to relieve stress concentrations near the reinforcements in metallic composites. The Ag-SnO2 contact materials with cuO additive are prepared by electroless plating combined with powder metallurgy method. The cuO nanoparticles in-situ formed on the SnO2 reinforcements are adopted to relieve local stress concentrations near the Ag/SnO2 interfaces and promote strain homogenization. The mechanical properties, deformation characteristics and microstructure evolution of the Ag-SnO2 composites without and with cuO additive are systematically studied by experiments and numerical simulations. The results show that the cuO nanoparticles formed on the surfaces of the SnO2 reinforcements dramatically improve the mechanical properties of the Ag-SnO2 composites, particularly the plasticity at a higher loading rate. It is demonstrated that the dislocation tangle around the cuO nanoparticles effectively relieves the adverse effect of the stress concentration near the SnO2 and results in the strain homogenization in the Ag matrix. Furthermore, the damage evolution of the Ag-SnO2 composites without and with cuO nanoparticles is investigated by the Gurson-Tvergaard-Needleman (GTN) models under uniaxial tension. The nucleation and growth of voids at the interfaces of the Ag-SnO2 composites are numerically simulated and discussed. This study provides a fundamental basis for developing novel high-performance metal matrix composites. © 2022, The Authors. All rights reserved.

关键词： Stress concentration

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：