【摘要】 研究悬臂端受到线性弹簧支承和扭转弹簧约束的约束悬臂输流管道在自激-参数激励-外激励联合激励作用下的非线性动力学特性,分析系统在平均流速、流速脉动幅值和基础激励下出现周期和混沌运动响应的参数条件,揭示其通向混沌的途径,探寻各参数对输流管道振动响应的影响,为输流管道的振动控制提供依据。数值仿真结果表明,随着平均流速、流速脉动幅值、基础激励幅值和质量比的不同,管道系统分别呈现周期、概周期、阵发性和混沌运动多种响应形式,系统通过倍周期分岔或阵发性进入混沌,通过倍周期倒分岔脱离混沌。更多还原

【Abstract】 The nonlinear dynamical characteristics of the cantilever piping system, restrained by linear and torque springs at its free end, under the excitation of pulsating fluid and harmonic motion of the base were investigated. The system parameters when periodic or chaotic motion was impending were analyzed to find out the forerunner of chaos, to reveal the regularity of the effect of these system parameters on vibration characteristics of the pipe, and to provide basic theory for its active control. Numerical results show that the system goes through the transitions from periodic motion, to quasi-periodic motion to intermittent chaos and then to chaotic motion with the changes of mean flow velocity, pulsating value of flowrate, amplitude of harmonic motion of the base and mass ratio. Doubling bifurcation and intermittent chaos are the two routes leading to chaotic motion, and the inverse doubling bifurcation is its converse way to leave chaotic motion.更多还原