Dynamic analysis steps and general flow of fast lagrangian analysis of continua in 3 dimensions(FLAC3D) were discussed. Numerical simulation for influence of excavation and blasting vibration on stability of mined-out...Dynamic analysis steps and general flow of fast lagrangian analysis of continua in 3 dimensions(FLAC3D) were discussed. Numerical simulation for influence of excavation and blasting vibration on stability of mined-out area was carried out with FLAC3D. The whole analytical process was divided into two steps, including the static analysis and the dynamic analysis which were used to simulate the influence of excavation process and blasting vibration respectively. The results show that the shape of right upper boundary is extremely irregular after excavation, and stress concentration occurs at many places and higher tensile stress appears. The maximum tensile stress is higher than the tensile strength of rock mass, and surrounding rock of right roof will be damaged with tension fracture. The maximum displacement of surrounding rock is 4.75 mm after excavation. However, the maximum displacement increases to 5.47 mm after the blasting dynamic load is applied. And the covering area of plastic zones expands obviously, especially at the foot of right upper slope. The analytical results are in basic accordance with the observed results on the whole. Damage and disturbance on surrounding rock to some degree are caused by excavation, while blasting dynamic load increases the possibility of occurrence of dynamic instability and destruction further. So the effective supporting and vibration reducing measures should be taken during mining.展开更多
Based on specific geology and mining conditions of certain coal working face in China, a series of numerical models under different unconsolidated layers thickness were respectively established by employing FLAC3D. Th...Based on specific geology and mining conditions of certain coal working face in China, a series of numerical models under different unconsolidated layers thickness were respectively established by employing FLAC3D. The relationship between the unconsolidated layers thickness and surface movement laws was studied. Maximum surface subsidence, Maximum horizontal displacement and surface subsidence degree were obtained. Contours of surface subsidence/horizontal displacement and curves were drawn. Some laws of surface subsidence/horizontal displacement were analyzed. The role of the unconsolidated layers in surface subsidence was revealed. It is significant to predict surface subsidence of thick unconsolidated layers for coal mine and take effective measures to control surface subsidence.展开更多
A 3-D finite-element numerical simulation model of temperature field for CIESC casting solidification process was developed with the aid of ANSYS software and a series of corresponding experiments were made. The resul...A 3-D finite-element numerical simulation model of temperature field for CIESC casting solidification process was developed with the aid of ANSYS software and a series of corresponding experiments were made. The results showed that the good agreement was obtained between the numerical simulation and the experiments. Based on the numerical simulation results, the characteristics of temperature distribution in the castings during CIESC solidification process were analyzed and summarized. According to the G/R-1/2 method and numerical simulation results, there is no any shrinkage defect in the CIESC casting and structure or casting is fine and compact.展开更多
基金Project (50490272) supported by the National Natural Science Foundation of China project(NCET-05-0687) supportedby Programfor New Century Excellent Talents project (040109) supported bythe Doctor Degree Paper Innovation Engineering of CentralSouth University
文摘Dynamic analysis steps and general flow of fast lagrangian analysis of continua in 3 dimensions(FLAC3D) were discussed. Numerical simulation for influence of excavation and blasting vibration on stability of mined-out area was carried out with FLAC3D. The whole analytical process was divided into two steps, including the static analysis and the dynamic analysis which were used to simulate the influence of excavation process and blasting vibration respectively. The results show that the shape of right upper boundary is extremely irregular after excavation, and stress concentration occurs at many places and higher tensile stress appears. The maximum tensile stress is higher than the tensile strength of rock mass, and surrounding rock of right roof will be damaged with tension fracture. The maximum displacement of surrounding rock is 4.75 mm after excavation. However, the maximum displacement increases to 5.47 mm after the blasting dynamic load is applied. And the covering area of plastic zones expands obviously, especially at the foot of right upper slope. The analytical results are in basic accordance with the observed results on the whole. Damage and disturbance on surrounding rock to some degree are caused by excavation, while blasting dynamic load increases the possibility of occurrence of dynamic instability and destruction further. So the effective supporting and vibration reducing measures should be taken during mining.
基金Project(2007BAK28B03)supported by the National Eleventh-Five Year Research Program of ChinaProject(2010YD05)supported by the Fundamental Research Funds for the Central UniversitiesProject(200911036)supported by the Ministry of Land and Resources Research Special
文摘Based on specific geology and mining conditions of certain coal working face in China, a series of numerical models under different unconsolidated layers thickness were respectively established by employing FLAC3D. The relationship between the unconsolidated layers thickness and surface movement laws was studied. Maximum surface subsidence, Maximum horizontal displacement and surface subsidence degree were obtained. Contours of surface subsidence/horizontal displacement and curves were drawn. Some laws of surface subsidence/horizontal displacement were analyzed. The role of the unconsolidated layers in surface subsidence was revealed. It is significant to predict surface subsidence of thick unconsolidated layers for coal mine and take effective measures to control surface subsidence.
文摘A 3-D finite-element numerical simulation model of temperature field for CIESC casting solidification process was developed with the aid of ANSYS software and a series of corresponding experiments were made. The results showed that the good agreement was obtained between the numerical simulation and the experiments. Based on the numerical simulation results, the characteristics of temperature distribution in the castings during CIESC solidification process were analyzed and summarized. According to the G/R-1/2 method and numerical simulation results, there is no any shrinkage defect in the CIESC casting and structure or casting is fine and compact.
