CAJ | 학술논문

机械结构系统中存在大量的结构，其固有频率会随着激振力幅的不同而改变，称之为刚度非线性结构，例如螺栓法兰联接结构、涂层复合结构等。由于存在刚度非线性，经典的半功率带宽法无法准确辨识这些结构的阻尼参数。本文在修正经典半功率带宽法的基础上，提出了一种适用于弱刚度及强刚度非线性系统的阻尼辨识方法，称为频域带宽法。首先，基于刚度非线性结构系统的运动方程，分别推导了弱刚度非线性及强刚度非线性系统的阻尼辨识公式。进一步，提出了基于频域带宽法测试具有刚度非线性结构系统的阻尼参数的方法及流程，并讨论了扫频方向、扫频速度对测试结果的影响。最后，以具有软式非线性特征的硬涂层薄板为对象进行实例研究，获得了该薄板不同激励幅度下的阻尼参数。本文的研究可为精确建立类似结构的动力学响应分析模型提供参考。
궤계결구계통중존재대량적결구，기고유빈솔회수착격진력폭적불동이개변，칭지위강도비선성결구，례여라전법란련접결구、도층복합결구등。유우존재강도비선성，경전적반공솔대관법무법준학변식저사결구적조니삼수。본문재수정경전반공솔대관법적기출상，제출료일충괄용우약강도급강강도비선성계통적조니변식방법，칭위빈역대관법。수선，기우강도비선성결구계통적운동방정，분별추도료약강도비선성급강강도비선성계통적조니변식공식。진일보，제출료기우빈역대관법측시구유강도비선성결구계통적조니삼수적방법급류정，병토론료소빈방향、소빈속도대측시결과적영향。최후，이구유연식비선성특정적경도층박판위대상진행실례연구，획득료해박판불동격려폭도하적조니삼수。본문적연구가위정학건립유사결구적동역학향응분석모형제공삼고。
There are a large number of structures,whose natural frequencies will vary with the exciting levels and they can be named as the stiffness-nonlinearity structures,such as the bolted joint structures,composite laminated plate structures,etc.Due to the effect of stiffness-nonlinearity,the classical time domain and frequency domain methods for damping identification will not be still suitable.Therefore,on the basis of modifying the classical half-power bandwidth method,a method used to identify the damping of weak or strong stiffness-nonlinearity structure systems was presented. Based on the motion equation of the stiffness-nonlinearity system,the formulas for damping identification were derived respectively for the weak and strong stiffness-nonlinearity structure systems.Then,a damping test procedure was proposed for the above mentioned nonlinear structure systems.The test case of a hard-coating cantilever thin plate with soft nonlinear characteristic was provided,where the damping parameters were obtained under different exciting levels by sweep test and the practicability and effectiveness of the method proposed was demonstrated.