Analyzed roof rock layer structure and rock layer thickness of -550 level west main roadway and proposed that the stability of calcareous rock layer was the premise of mining successfully. According to different roof ...Analyzed roof rock layer structure and rock layer thickness of -550 level west main roadway and proposed that the stability of calcareous rock layer was the premise of mining successfully. According to different roof condition and rock pillar size of main roadway, different reinforcement plans were used to strengthen the stability of rock layer. By studying the influence rule and influence scope of dynamic pressure of main roadway wall rock because of fully mechanized coal face extracting, that the size of rock pillar was the key of affecting wall rock distorting was proposed. Scientific basis was provided for determining the size of reasonable rock pillar, selecting reasonable extracting support plan and reinforcement measures under different wall rock conditions.展开更多
A recently emerging family of smart materials,photostrictive materials,exhibit large photostriction under uniform illumination of high-energy light.This photostriction mechanism arises from a superposition phenomenon ...A recently emerging family of smart materials,photostrictive materials,exhibit large photostriction under uniform illumination of high-energy light.This photostriction mechanism arises from a superposition phenomenon of photovoltaic and converse piezoelectric effects.A photostrictive type of opto-electromechanical actuator activated by high-energy lights can introduce actuation and control effects without hard-wired connections.The control light intensity applied to the actuator is proportional to the transverse velocity at a positioned point,which is measured by a laser vibrometer.In this paper,photostrictive films are numerically analyzed to evaluate their use as wireless actuators for future remote vibration control of flexible structures.A novel opto-electromechanical solid shell finite element formulation is developed for accurate analysis of the multiple physics effects of photovoltaic,pyroelectric and thermal expansion of photostrictive materials.Available experimental data and analytical solutions have been used to verify the present finite element results.The simulation in this study demonstrates that the present formulation is very reliable,accurate and also computationally efficient and that the use of photostrictive actuators can provide good controllability of structural vibration.展开更多
文摘Analyzed roof rock layer structure and rock layer thickness of -550 level west main roadway and proposed that the stability of calcareous rock layer was the premise of mining successfully. According to different roof condition and rock pillar size of main roadway, different reinforcement plans were used to strengthen the stability of rock layer. By studying the influence rule and influence scope of dynamic pressure of main roadway wall rock because of fully mechanized coal face extracting, that the size of rock pillar was the key of affecting wall rock distorting was proposed. Scientific basis was provided for determining the size of reasonable rock pillar, selecting reasonable extracting support plan and reinforcement measures under different wall rock conditions.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10872090, 50830201)NUAA Research Funding (Grant No. NJ2010011)
文摘A recently emerging family of smart materials,photostrictive materials,exhibit large photostriction under uniform illumination of high-energy light.This photostriction mechanism arises from a superposition phenomenon of photovoltaic and converse piezoelectric effects.A photostrictive type of opto-electromechanical actuator activated by high-energy lights can introduce actuation and control effects without hard-wired connections.The control light intensity applied to the actuator is proportional to the transverse velocity at a positioned point,which is measured by a laser vibrometer.In this paper,photostrictive films are numerically analyzed to evaluate their use as wireless actuators for future remote vibration control of flexible structures.A novel opto-electromechanical solid shell finite element formulation is developed for accurate analysis of the multiple physics effects of photovoltaic,pyroelectric and thermal expansion of photostrictive materials.Available experimental data and analytical solutions have been used to verify the present finite element results.The simulation in this study demonstrates that the present formulation is very reliable,accurate and also computationally efficient and that the use of photostrictive actuators can provide good controllability of structural vibration.
