研究了MTVMD(multiple tuned viscous mass damper)对单自由度结构在简谐荷载作用下的参数优化设计及减震效果,分析了结构参数变动时系统的鲁棒性.以位移和加速度动力放大系数为优化目标,运用改进模式搜索法搜寻MTVMD最优参数.分析表明...研究了MTVMD(multiple tuned viscous mass damper)对单自由度结构在简谐荷载作用下的参数优化设计及减震效果,分析了结构参数变动时系统的鲁棒性.以位移和加速度动力放大系数为优化目标,运用改进模式搜索法搜寻MTVMD最优参数.分析表明,增加质量比和子TVMD个数,MTVMD的减震性能增强,且结构参数变动时,系统鲁棒性增强.考虑阻尼器在实际工作状态时的参数可能会偏离最优参数,假定各子TVMD参数偏离服从正态分布,利用蒙特卡罗试验法对比分析了STVMD(single tuned viscous mass damper)和MTVMD自身参数最不利偏离状态时的减震有效性和可靠性.数值结果表明,STVMD的减震有效性和可靠性与子TVMD个数正相关,MTVMD则存在一个最优子TVMD个数使得减震有效性最佳;STVMD和MTVMD减震性能与参数最大偏离率负相关.展开更多
The control problem for under-actuated reentry vehicle like HTV-2 is considered with small angle of attack.The control strategy for an aircraft with positive lateral control departure parameter relies on strong latera...The control problem for under-actuated reentry vehicle like HTV-2 is considered with small angle of attack.The control strategy for an aircraft with positive lateral control departure parameter relies on strong lateral stability,which declines with the decrease of the angle of attack.Thus,to control the lateral-directional motion in a stable state is hard and even impossible in some scenarios where the under-actuated reentry vehicle,like HTV-2,flies in a low angle of attack.To address this problem,the lateral-directional open-loop motion characteristics are analyzed.The results show that in an uncontrolled state,the lateral-directional motion can automatically converge to stabilization thanks to the aerodynamic damping effect.Therefore,a method of turning-off the lateral-directional control and inviting aerodynamic damping to control can achieve stability.The six-degree-of-freedom simulation show that the lateral-directional motion can be stabilized by the aerodynamic damping,and the lateral position error caused by the bank angle deviation is limited near the zero-rise angle of attack.The control strategy is effective.展开更多
文摘研究了MTVMD(multiple tuned viscous mass damper)对单自由度结构在简谐荷载作用下的参数优化设计及减震效果,分析了结构参数变动时系统的鲁棒性.以位移和加速度动力放大系数为优化目标,运用改进模式搜索法搜寻MTVMD最优参数.分析表明,增加质量比和子TVMD个数,MTVMD的减震性能增强,且结构参数变动时,系统鲁棒性增强.考虑阻尼器在实际工作状态时的参数可能会偏离最优参数,假定各子TVMD参数偏离服从正态分布,利用蒙特卡罗试验法对比分析了STVMD(single tuned viscous mass damper)和MTVMD自身参数最不利偏离状态时的减震有效性和可靠性.数值结果表明,STVMD的减震有效性和可靠性与子TVMD个数正相关,MTVMD则存在一个最优子TVMD个数使得减震有效性最佳;STVMD和MTVMD减震性能与参数最大偏离率负相关.
文摘The control problem for under-actuated reentry vehicle like HTV-2 is considered with small angle of attack.The control strategy for an aircraft with positive lateral control departure parameter relies on strong lateral stability,which declines with the decrease of the angle of attack.Thus,to control the lateral-directional motion in a stable state is hard and even impossible in some scenarios where the under-actuated reentry vehicle,like HTV-2,flies in a low angle of attack.To address this problem,the lateral-directional open-loop motion characteristics are analyzed.The results show that in an uncontrolled state,the lateral-directional motion can automatically converge to stabilization thanks to the aerodynamic damping effect.Therefore,a method of turning-off the lateral-directional control and inviting aerodynamic damping to control can achieve stability.The six-degree-of-freedom simulation show that the lateral-directional motion can be stabilized by the aerodynamic damping,and the lateral position error caused by the bank angle deviation is limited near the zero-rise angle of attack.The control strategy is effective.
