In order to continuously simulate multi-pass plate rolling process,a 3-D elastic hollow-roll model was proposed and an auto mesh-refining module with data passing was developed and integrated with FE software,Marc.The...In order to continuously simulate multi-pass plate rolling process,a 3-D elastic hollow-roll model was proposed and an auto mesh-refining module with data passing was developed and integrated with FE software,Marc.The hollow-roll model has equivalent stiffness of bending resistance and deformation to the real solid and much less meshes,so the computational time is greatly reduced.Based on these,the factors influencing plate profile,such as the roll-bending force,initial crown,thermal crown and heat transfer during rolling and inter-pass cooling can be taken into account in the simulation.The auto mesh-refining module with data passing can automatically refine and re-number elements and transfer the nodal and elemental results to the new meshes.Furthermore,the 3-D modeling routine is parametrically developed and can be run independently of Marc pre-processing program.A seven-pass industrial hot rolling process was continuously simulated to validate the accuracy of model.By comparison of the calculated results with the industrial measured data,the rolling force,temperature and plate profile are in good accordance with the measured ones.展开更多
Based on the decline in exploitation of coal resources, steep coal seam mining and mining face tensions continue to explore the feasibility analysis of steeply inclined faces in the gob. One of the key factors in util...Based on the decline in exploitation of coal resources, steep coal seam mining and mining face tensions continue to explore the feasibility analysis of steeply inclined faces in the gob. One of the key factors in utilizing the technology of gob-side entry retaining in steep coal seams is to safely and effectively prevent caving rock blocks from rushing into the gob-side entry by sliding downwards along levels. Using theoretical analysis and field methods, we numerically simulated the mining process on a fully-mechanized face in a steep coal seam. The stress and deformation process of roof strata has been analyzed, and the difficulty of utilizing the technology is considered and combined with practice in a steep working face in Lvshuidong mine. The feasibility of utilizing the technology of gob-side entry retaining in a steep coal seam has been recognised. We propose that roadways along the left lane offshoot body use a speciallymade reinforced steel dense net to build a dense rock face at the lower head. The results show that the lane offshoot branch creates effective roof control, safe conditions for roadway construction workers, and practical application of steeply inclined gob.展开更多
A 3D t＇mite element model of the explosive welding process of three-layer plates with materials of steel-copper-copper is es- tablished. Based on the presented model, the bonding mechanism is simulated and analyzed, ...A 3D t＇mite element model of the explosive welding process of three-layer plates with materials of steel-copper-copper is es- tablished. Based on the presented model, the bonding mechanism is simulated and analyzed, different detonation modes are also comparatively studied to indicate the driving force spread in few microseconds. The results show that the three layer plates bond together after many times of impact between the flyers and the base driven by detonation wave, which is damping rapidly at each impact with wavelength decreasing. The pressure at the detonation point is minimal, which induces non-bonding of the plates here. Detonation wave propagates in concentric circle both under side-midpoint detonation mode and under center-point detonation mode, but the movement of the flyer is different, which makes non-bonding easily occur at the end of detonation under side-midpoint detonation and at the center of the plate under center-point detonation.展开更多
The synthesis of mesoporous material SBA-15 has been extensively reported in the past decades, which possesses a pore diameter of 6-8 nm on average. Here, a simple post-synthesis procedure has been developed to synthe...The synthesis of mesoporous material SBA-15 has been extensively reported in the past decades, which possesses a pore diameter of 6-8 nm on average. Here, a simple post-synthesis procedure has been developed to synthesize SBA-15 with further expanded pore diameter to above 10 nm simply by a solvothermal treatment replacing traditional hydrothermal step for mesopore template removal, which results in efficient pore expansion and the significantly promoted condensation of silica framework as well. This facile approach is believed applicable for pore expansions of other kinds of mesoporous silica materials.展开更多
基金Project(20050248007) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘In order to continuously simulate multi-pass plate rolling process,a 3-D elastic hollow-roll model was proposed and an auto mesh-refining module with data passing was developed and integrated with FE software,Marc.The hollow-roll model has equivalent stiffness of bending resistance and deformation to the real solid and much less meshes,so the computational time is greatly reduced.Based on these,the factors influencing plate profile,such as the roll-bending force,initial crown,thermal crown and heat transfer during rolling and inter-pass cooling can be taken into account in the simulation.The auto mesh-refining module with data passing can automatically refine and re-number elements and transfer the nodal and elemental results to the new meshes.Furthermore,the 3-D modeling routine is parametrically developed and can be run independently of Marc pre-processing program.A seven-pass industrial hot rolling process was continuously simulated to validate the accuracy of model.By comparison of the calculated results with the industrial measured data,the rolling force,temperature and plate profile are in good accordance with the measured ones.
文摘Based on the decline in exploitation of coal resources, steep coal seam mining and mining face tensions continue to explore the feasibility analysis of steeply inclined faces in the gob. One of the key factors in utilizing the technology of gob-side entry retaining in steep coal seams is to safely and effectively prevent caving rock blocks from rushing into the gob-side entry by sliding downwards along levels. Using theoretical analysis and field methods, we numerically simulated the mining process on a fully-mechanized face in a steep coal seam. The stress and deformation process of roof strata has been analyzed, and the difficulty of utilizing the technology is considered and combined with practice in a steep working face in Lvshuidong mine. The feasibility of utilizing the technology of gob-side entry retaining in a steep coal seam has been recognised. We propose that roadways along the left lane offshoot body use a speciallymade reinforced steel dense net to build a dense rock face at the lower head. The results show that the lane offshoot branch creates effective roof control, safe conditions for roadway construction workers, and practical application of steeply inclined gob.
基金supported by the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University (Grant No. SKLSP200906 )111 Project (Grant No. B08040)
文摘A 3D t＇mite element model of the explosive welding process of three-layer plates with materials of steel-copper-copper is es- tablished. Based on the presented model, the bonding mechanism is simulated and analyzed, different detonation modes are also comparatively studied to indicate the driving force spread in few microseconds. The results show that the three layer plates bond together after many times of impact between the flyers and the base driven by detonation wave, which is damping rapidly at each impact with wavelength decreasing. The pressure at the detonation point is minimal, which induces non-bonding of the plates here. Detonation wave propagates in concentric circle both under side-midpoint detonation mode and under center-point detonation mode, but the movement of the flyer is different, which makes non-bonding easily occur at the end of detonation under side-midpoint detonation and at the center of the plate under center-point detonation.
基金supported by the National Basic Research Program of China(2012CB933602)the National Natural Science Foundation of China(51172070,51132009,51202068 and51472085)+1 种基金Shu Guang Project(11SG30)the Fundamental Research Funds for the Central Universities
文摘The synthesis of mesoporous material SBA-15 has been extensively reported in the past decades, which possesses a pore diameter of 6-8 nm on average. Here, a simple post-synthesis procedure has been developed to synthesize SBA-15 with further expanded pore diameter to above 10 nm simply by a solvothermal treatment replacing traditional hydrothermal step for mesopore template removal, which results in efficient pore expansion and the significantly promoted condensation of silica framework as well. This facile approach is believed applicable for pore expansions of other kinds of mesoporous silica materials.
