基于测试数据的卡箍非线性等效建模方法

为了快速准确地计算卡箍管路系统的振动响应，提出了基于测试数据的卡箍非线性等效建模方法。对卡箍直管系统进行低幅值激励的模态测试，利用试验数据对有限元模型进行修正，识别卡箍线性刚度、线性阻尼参数。对卡箍直管系统开展不同激励水平下的恒力测试，通过样条插值多项式法将恒力频响函数转换为恒位移、恒速度频响函数，并进一步识别卡箍非线性等效刚度、非线性等效阻尼，建立了考虑卡箍非线性的等效动力学模型。研究表明:该卡箍等效动力学模型的预测频响函数与试验频响函数的最大误差仅为-6.9%，可以有效地反映卡箍实际的刚度、阻尼特性，对解决卡箍管路系统的振动响应分析具有重要的指导意义。 

Nonlinear equivalent modeling method for clamp based on test data

In order to calculate the vibration response of clamp piping system quickly and accurately, a nonlinear equivalent modeling method for clamp was presented based on test data. The finite element model of simple straight pipe system was modified by the test data of modal test to identify the liner stiffness and damping parameters of clamp. The constant force test was carried out for the simple straight pipe system under different excitation levels. The constant force frequency response function was transformed into constant displacement and constant velocity frequency response function by spline interpolation polynomial method, and the nonlinear equivalent stiffness and damping of clamp were further identified. Finally, the equivalent dynamic model of clamp considering nonlinearity was established. The results showed the maximum error between the predicted frequency response functions and the experimental frequency response functions was only -6.9%. It proves that the equivalent dynamic model of clamp can effectively reflect the actual stiffness and damping characteristics of clamp, and has important guiding significance in vibration response analysis of clamp piping system.