管道联接件参数识别的波动方法

基于波动理论,提出了一种识别管道联接件物理参数的新方法.以直管在平面内的弯曲振动为例,将弯曲波分解为左、右行波和衰减波,建立起管道单元上各测量点功率谱与波谱的关系,并由联接件处位移连续及力平衡条件,将联接件刚度及阻尼表示成波谱的函数.由联接件物理参数的辨识转化为与联接件相连管道单元上波谱的辨识.最后通过数值算例验证了波动方法在管道联接件物理参数辨识中的可行性.结果表明,波动方法在参数辨识中具有良好的识别精度和数值稳定性,是一种极有潜力的参数辨识方法.

Identification of pape joint paramers by wave method

A new method to identify the joint parameters of piping systems based on wave method is presented. For flexural vibration of piping systems in two dimensions, it is possible to obtain the expressions for incident, reflected and near field wave spectra in terms of the measured auto-and cross-spectra of an array of closely spaced accelerometers. With expressions for the wave spectrum, the joint stiffness and damping can be derived according to the condition of force equilibrium and displacement continuum. During the identification procedure, the dynamic stiffness is separated into real and imaginary parts in order to identify the stiffness and damping parameters independently. The auto-and cross- spectra for each discrete frequency are employed so that the joint parameters could be estimated for each frequency and averaged using statistical methods. The validity and feasibility of the approach are shown using a numerical example. The results indicate that wave method has a good precision for the identification of joint parameters.