【摘要】 研究了两端受扭转弹簧约束的简支输流管道的固有频率特性和静态失稳临界流速.根据梁模型横向弯曲振动模态函数,由端部支承和约束边界条件得到了其模态函数的一般表达式.根据动力方程的特征方程,具体分析了约束弹性刚度、流体压强、流速和管截面轴向力等参数对管道固有频率特性和静态失稳临界流速的影响.数值分析表明,约束弹性刚度的增大使管道的固有频率和失稳临界流速明显提高;流体流速、压强和管截面受到的轴向压力的增加使管道的固有频率和失稳临界流速降低.当管道的固有频率和失稳临界流速较低时,可以通过增加端部约束的方法来提高.更多还原

【Abstract】 This paper investigated the natural frequency and static critical flow velocity of simply supported pipes conveying fluid with both ends restrained elastically.The expression of vertical vibration mode-function of pipeline was derived from the boundary condition of simply supports with elastic restrained beam.The effects of restraining elastic coefficient,fluid pressure,fluid flow rate and axial force of pipe section on the characteristics of natural frequency and static critical instability flow velocity were calculated and analyzed based on the eigenequation.The numerical results show that the natural frequency and critical instability flow velocity are proportional to elastic restraining coefficient,but is proportional conversely to flow velocity,fluid pressure and axial sectional drawn force of pipe.It is a convenient and effective way to increase the natural frequency and critical instability flow velocity of pipeline through additional elastic restraining with proper coefficient on two ends while their values are low.更多还原