CAJ | 학술논문

主轴系统的模态参数是加工稳定性预测及参数优化等的重要依据。针对主轴系统难以实施有效激励的问题，提出了基于多点脉冲激励的运行模态分析(Operational modal analysis，OMA)方法，对刀具、刀柄及主轴分别施加脉冲激励，获取测点的振动响应及互相关函数，采用多参考最小二乘复指数法(poly-reference least square complex exponential method, pLSCE)识别了模态参数。通过模态置信判据方法剔除识别过程所衍生的虚假模态，提高了模态参数识别的准确性。与锤击模态试验结果的对比表明，识别的固有频率与阻尼比的最大相对误差分别为4.57%和11.02%，一致性较好，表明由多点激励下响应信号的互相关函数可准确识别主轴系统模态参数，为主轴系统运行模态分析提供了一种新思路。
주축계통적모태삼수시가공은정성예측급삼수우화등적중요의거。침대주축계통난이실시유효격려적문제，제출료기우다점맥충격려적운행모태분석(Operational modal analysis，OMA)방법，대도구、도병급주축분별시가맥충격려，획취측점적진동향응급호상관함수，채용다삼고최소이승복지수법(poly-reference least square complex exponential method, pLSCE)식별료모태삼수。통과모태치신판거방법척제식별과정소연생적허가모태，제고료모태삼수식별적준학성。여추격모태시험결과적대비표명，식별적고유빈솔여조니비적최대상대오차분별위4.57%화11.02%，일치성교호，표명유다점격려하향응신호적호상관함수가준학식별주축계통모태삼수，위주축계통운행모태분석제공료일충신사로。
Modal parameters of the spindle system is an important basis for the prediction of processing stability and parameters optimization. Aiming at the difficulty in the implementation of effective incentive for the spindle system, a new operational modal analysis (OMA) method based on multiple pulse excitation is brought forward, pulse excitations are respectively applied on the tool, toolholder and spindle, response and cross-correlation functions of vibration signals are achieved and modal parameters are identified through the poly-reference least square complex exponential (pLSCE) method. False modes derived from the recognition process is removed to improve the accuracy of modal parameters identification by the modal assurance criterion method. Comparative analysis shows that the maximum relative error of the natural frequency and damping ratio is 4.57% and 11.02%respectively and the OMA results are in good agreement with the hammer modal test results. Results indicate the modal parameters of spindle system can be accurately identified by the cross-correlation functions of response signals under multiple pulse excitation, the work provide a new method for OMA of spindle system.