CAJ | 학술논문

大型旋转机械转轴裂纹具有复杂的高维非线性特征，由此产生的机械故障时有发生。根据航空发动机低压转子系统，利用拉格朗日原理建立了具有26个自由度的含有裂纹故障的高维非线性动力学模型。引进改进的POD方法成功将该系统降为具有两个自由度含有特征的低维非线性系统。数值模拟结果显示降维系统具有与原系统一致的非线性动力学特征，表明本方法对解决高维非线性问题具有较好的有效性。此外，还利用C-L方法对其进行分岔分析，讨论了系统参数与系统动态行为之间的关系，得到了裂纹转子各种不同分岔模式，得到了裂纹二分之一亚谐共振条件下的非线性动力学特性，准确反映了裂纹转子的动力学特征。
대형선전궤계전축렬문구유복잡적고유비선성특정，유차산생적궤계고장시유발생。근거항공발동궤저압전자계통，이용랍격랑일원리건립료구유26개자유도적함유렬문고장적고유비선성동역학모형。인진개진적POD방법성공장해계통강위구유량개자유도함유특정적저유비선성계통。수치모의결과현시강유계통구유여원계통일치적비선성동역학특정，표명본방법대해결고유비선성문제구유교호적유효성。차외，환이용C-L방법대기진행분차분석，토론료계통삼수여계통동태행위지간적관계，득도료렬문전자각충불동분차모식，득도료렬문이분지일아해공진조건하적비선성동역학특성，준학반영료렬문전자적동역학특정。
Crack fault is an often occurring complex high-dimensional nonlinear problem in large rotating machinery systems.Here,a low-pressure rotor system with a pair of liquid film lubricated bearings was modeled into a 26-DOF nonlinear system using Lagrange method.This high dimensional nonlinear system was reduced into a 2-DOF system with a crack fault and oil-film oscillation property by introducing the modified POD method.Numerical simulations demonstrated the effectiveness of the proposed method.the compavison between the computed results of the reduced system and those of the original system showed that both of the two systems have the consistent nonlinear dynamic features.C-L method was also employed to obtain the dynamical behaviors of the reduced system,they reflected the dynamic property of a cracked rotor system.