The stability of cemented backfill mass is important to keep miners and equipment safe in underground backfill miming.The stress-strain behavior, resistivity and thermal infrared(TIR) characteristics of backfill mass ...The stability of cemented backfill mass is important to keep miners and equipment safe in underground backfill miming.The stress-strain behavior, resistivity and thermal infrared(TIR) characteristics of backfill mass under uniaxial compression were investigated. The monitoring system consisted of a TIR observation system, a stress-strain monitoring system and a resistivity measurement system. Precursory information for impending failure of cemented backfill mass was collected, including TIR, strain and resistivity precursors. The sensitivity and difference of different monitoring information to the same failure event were compared.The results show that the time-space evolution process of the resistivity and TIR is basically the same as the whole process from compression deformation to failure of backfill mass, and the time variation of resistivity and TIR is obviously characterized by stage.The resistivity precursor turns out earlier than the TIR and the strain. The resistivity relation with loading compression is anti-symmetry, decreasing as the compression stress increases before the peak strength of backfill mass. However, when the backfill mass enters into the phase of failure, the resistivity starts to increase as the stress increases. The change of the resistivity growth direction can be regarded as the resistivity-caution-point for the failure of backfill mass under uniaxial compression. It is also indicated that the TIR information mainly represents the surface temperature evolution in the process of compression before the backfill enters into the plastic-yield state. It can be a valuable tool to obtain the precursors for failure of cemented backfill mass for backfill mines.展开更多
Based on the architectural survey project of "the Chi Lin Nunnery Redevelopment "in Hong Kong,this paper attempts to investigate the techniques of building 3D digital document of large_scale timber structure...Based on the architectural survey project of "the Chi Lin Nunnery Redevelopment "in Hong Kong,this paper attempts to investigate the techniques of building 3D digital document of large_scale timber structure and quality control during construction by computer_based 3D simulation for the whole project.There were several key issues including primary data acquisition,3D modeling and display,pre_assembling the total building and quality examination,etc.In this paper,some useful experiments,such as the new applications of CCD digital cameras,image and graph processing software packages (CAD,Photoshop,Photomodeler,Vexcel,etc.) to the architectures are also presented.These methods introduced in this paper are suitable for image and graph integrated database building of complicated architectures,and useful for conveniently maintaining and reconstructing the ancient architectures.展开更多
Traditional variation analysis methods are not applicable to non-rigid assemblies due to possible part deformation during the assembly process. This paper presents the use of finite element methods to simulate assembl...Traditional variation analysis methods are not applicable to non-rigid assemblies due to possible part deformation during the assembly process. This paper presents the use of finite element methods to simulate assembly deformation. The relationship between the parts’ variation and the variation of the key points in final assembly for quality control is set up by calculating the spring back deformation after assembly. Moreover, the optimization method for non-rigid assembly variations based on finite element analysis is presented. The optimal objective is to reduce the manufacturing cost. The approach is implemented by using ANSYS and MATLAB. The test example shows that the proposed method is effective and applicable.展开更多
The objective of this research is to reduce waste in the production ceramics of Ceramics Factory in Thailand. The 7 Quality Control Tools (7 QC Tools) were implemented including Check sheet, Graph, Pareto diagram an...The objective of this research is to reduce waste in the production ceramics of Ceramics Factory in Thailand. The 7 Quality Control Tools (7 QC Tools) were implemented including Check sheet, Graph, Pareto diagram and Fishbone diagram, which were used to analyze and solve the problems. It was found that most of the wastes come from burning ceramics process. The kilns and trolleys has been used for a long time. Furthermore, the equipment and parts were damaged from lack of maintenance. The non-standard of product arrangement method into the kilns were the cause of waste. Thus, the researcher improved trolleys into the kilns and designed a fixture to help worker to product arrangement. The results of the research gathered data from quality inspection department. Then comparing data before the improvement (between September 2013 to December 2013) and after the improvement (between November 2014 to February 2015), the wastes are reduced from 8.97% to 0.29%. The result of improving is very efficiency because it can reduce the wastes by 8.68%.展开更多
基金Projects(51504256,51004109)supported by the National Natural Science Foundation of ChinaProject(zdsys006)supported by State Key Laboratory of Safety and Health for Metal Mines,ChinaProject(2013BAB02B04)supported by the National Science and Technology Support Plan,China
文摘The stability of cemented backfill mass is important to keep miners and equipment safe in underground backfill miming.The stress-strain behavior, resistivity and thermal infrared(TIR) characteristics of backfill mass under uniaxial compression were investigated. The monitoring system consisted of a TIR observation system, a stress-strain monitoring system and a resistivity measurement system. Precursory information for impending failure of cemented backfill mass was collected, including TIR, strain and resistivity precursors. The sensitivity and difference of different monitoring information to the same failure event were compared.The results show that the time-space evolution process of the resistivity and TIR is basically the same as the whole process from compression deformation to failure of backfill mass, and the time variation of resistivity and TIR is obviously characterized by stage.The resistivity precursor turns out earlier than the TIR and the strain. The resistivity relation with loading compression is anti-symmetry, decreasing as the compression stress increases before the peak strength of backfill mass. However, when the backfill mass enters into the phase of failure, the resistivity starts to increase as the stress increases. The change of the resistivity growth direction can be regarded as the resistivity-caution-point for the failure of backfill mass under uniaxial compression. It is also indicated that the TIR information mainly represents the surface temperature evolution in the process of compression before the backfill enters into the plastic-yield state. It can be a valuable tool to obtain the precursors for failure of cemented backfill mass for backfill mines.
文摘Based on the architectural survey project of "the Chi Lin Nunnery Redevelopment "in Hong Kong,this paper attempts to investigate the techniques of building 3D digital document of large_scale timber structure and quality control during construction by computer_based 3D simulation for the whole project.There were several key issues including primary data acquisition,3D modeling and display,pre_assembling the total building and quality examination,etc.In this paper,some useful experiments,such as the new applications of CCD digital cameras,image and graph processing software packages (CAD,Photoshop,Photomodeler,Vexcel,etc.) to the architectures are also presented.These methods introduced in this paper are suitable for image and graph integrated database building of complicated architectures,and useful for conveniently maintaining and reconstructing the ancient architectures.
基金Supported by the Natural Science Foundation of China (No. 50205028) and the Natural Science Foundation of Chongqing City (No. 2005BB2022 ).
文摘Traditional variation analysis methods are not applicable to non-rigid assemblies due to possible part deformation during the assembly process. This paper presents the use of finite element methods to simulate assembly deformation. The relationship between the parts’ variation and the variation of the key points in final assembly for quality control is set up by calculating the spring back deformation after assembly. Moreover, the optimization method for non-rigid assembly variations based on finite element analysis is presented. The optimal objective is to reduce the manufacturing cost. The approach is implemented by using ANSYS and MATLAB. The test example shows that the proposed method is effective and applicable.
文摘The objective of this research is to reduce waste in the production ceramics of Ceramics Factory in Thailand. The 7 Quality Control Tools (7 QC Tools) were implemented including Check sheet, Graph, Pareto diagram and Fishbone diagram, which were used to analyze and solve the problems. It was found that most of the wastes come from burning ceramics process. The kilns and trolleys has been used for a long time. Furthermore, the equipment and parts were damaged from lack of maintenance. The non-standard of product arrangement method into the kilns were the cause of waste. Thus, the researcher improved trolleys into the kilns and designed a fixture to help worker to product arrangement. The results of the research gathered data from quality inspection department. Then comparing data before the improvement (between September 2013 to December 2013) and after the improvement (between November 2014 to February 2015), the wastes are reduced from 8.97% to 0.29%. The result of improving is very efficiency because it can reduce the wastes by 8.68%.