A new intelligent tester system for measuring multiple mechanical properties of foundry molding sand is introduced and has been patented for the invention in China. The testing process can be simultaneously controlled...A new intelligent tester system for measuring multiple mechanical properties of foundry molding sand is introduced and has been patented for the invention in China. The testing process can be simultaneously controlled with a build-in chip microcomputer communicating with a PC through a serial port. The testing system applies dynamic testing technology. During the measurement for compression, relaxation, shearing and tensile processes of sand specimens, the corresponding characteristic curves and eight mechanical property parameters can be obtained in a short time, simply by consecutively testing on four sand specimens. The properties and parameters to be measurable by the tester include compressive strength, elastic modulus, plastic deformation threshold, springback potential, shear strength, shear deformation limit, toughness and tensile strength. These properties and parameters for sand specimens can be defined as the corresponding characteristic curves with precise physical meanings, carried out by the tester, Two of them, namely plastic deformation threshold and springback potential, as well as their testing methods, have been invented for the first time. The testing system applying advanced data measurement technology as well as performing excellent functions is an important breakthrough and creativity in foundry molding sand property testing field. The parameters acquired by the testing system are stable, accurate and reliable. The test data can be instantly displayed or printed out or stored in the PC. As evidence, many experimental data obtained by the tester practically from both laboratory and foundry floor tests indicate that the tester system can be widely applied in foundry industry.展开更多
The loess slumping hazard is a special type of slope failures in the northern area of loess plateau of China. The characteristics of paroxysm and high frequency of the hazard always lead to ruin of cave houses, as we...The loess slumping hazard is a special type of slope failures in the northern area of loess plateau of China. The characteristics of paroxysm and high frequency of the hazard always lead to ruin of cave houses, as well as a high human casualties. The hazard is also seriously harmful to railways, highroads and long transporting pipelines. With the mechanisms of both landslide and falling, as well as the forming process of sliding followed by collapses, loess slumping is used to be treated as landslide or falling. Based on field investigations and lab analyses of the loess between Jingbian County of Shaanxi Province and Puxian County of Shanxi Province along the line of west east gas transportation project which is 300 km long, it is discovered that the hazards of loess slumping are controlled by the content of clay, which lead to their obvious regional properties: the area with a content of clay (<0.005 mm) less than 10 %, called sand loess area, is a seriously developing area of slumping; the area with a content of clay between 10 % and 20 %, called typical loess area, is a medium developing area of slumping; the area with a content of clay more than 20 %, called clay loess area, is a non developing area of slumping. Based on research of the formation mechanism and formation conditions of the loess slumping hazards, some corresponding engineering countermeasures are suggested in this paper.展开更多
文摘A new intelligent tester system for measuring multiple mechanical properties of foundry molding sand is introduced and has been patented for the invention in China. The testing process can be simultaneously controlled with a build-in chip microcomputer communicating with a PC through a serial port. The testing system applies dynamic testing technology. During the measurement for compression, relaxation, shearing and tensile processes of sand specimens, the corresponding characteristic curves and eight mechanical property parameters can be obtained in a short time, simply by consecutively testing on four sand specimens. The properties and parameters to be measurable by the tester include compressive strength, elastic modulus, plastic deformation threshold, springback potential, shear strength, shear deformation limit, toughness and tensile strength. These properties and parameters for sand specimens can be defined as the corresponding characteristic curves with precise physical meanings, carried out by the tester, Two of them, namely plastic deformation threshold and springback potential, as well as their testing methods, have been invented for the first time. The testing system applying advanced data measurement technology as well as performing excellent functions is an important breakthrough and creativity in foundry molding sand property testing field. The parameters acquired by the testing system are stable, accurate and reliable. The test data can be instantly displayed or printed out or stored in the PC. As evidence, many experimental data obtained by the tester practically from both laboratory and foundry floor tests indicate that the tester system can be widely applied in foundry industry.
文摘The loess slumping hazard is a special type of slope failures in the northern area of loess plateau of China. The characteristics of paroxysm and high frequency of the hazard always lead to ruin of cave houses, as well as a high human casualties. The hazard is also seriously harmful to railways, highroads and long transporting pipelines. With the mechanisms of both landslide and falling, as well as the forming process of sliding followed by collapses, loess slumping is used to be treated as landslide or falling. Based on field investigations and lab analyses of the loess between Jingbian County of Shaanxi Province and Puxian County of Shanxi Province along the line of west east gas transportation project which is 300 km long, it is discovered that the hazards of loess slumping are controlled by the content of clay, which lead to their obvious regional properties: the area with a content of clay (<0.005 mm) less than 10 %, called sand loess area, is a seriously developing area of slumping; the area with a content of clay between 10 % and 20 %, called typical loess area, is a medium developing area of slumping; the area with a content of clay more than 20 %, called clay loess area, is a non developing area of slumping. Based on research of the formation mechanism and formation conditions of the loess slumping hazards, some corresponding engineering countermeasures are suggested in this paper.
