(1. 重慶大學(xué) 機(jī)械工程學(xué)院，重慶 400030；
2. 重慶大學(xué) 國家鎂合金材料工程技術(shù)研究中心，重慶 400030；
3. 重慶建設(shè)摩托車股份有限公司，重慶 400050)
摘 要: 采用多參考最小二乘復(fù)頻法對具有相同結(jié)構(gòu)的AZ91D鎂合金試件和A380鋁合金試件進(jìn)行模態(tài)參數(shù)識別。在同等激勵(lì)脈沖輸入條件下進(jìn)行2種材料時(shí)域激勵(lì)響應(yīng)特征的多特征點(diǎn)對比測試，比較AZ91D鎂合金替換A380鋁合金前后試件結(jié)構(gòu)動(dòng)力學(xué)性能的差異，通過整體頻響函數(shù)和激勵(lì)響應(yīng)特性對AZ91D鎂合金阻尼減振的工程實(shí)際效果進(jìn)行評價(jià)。結(jié)果表明：在幾何結(jié)構(gòu)相同的情況下，2種材料的固有頻率和固有振型模態(tài)參數(shù)相似，AZ91D鎂合金試件具有更好的模態(tài)阻尼比。但由于鎂合金材料剛性較低，僅通過直接的材料替換，鎂合金材料的高阻尼減振性難以在實(shí)際工程中得到有效表現(xiàn)。
關(guān)鍵字: 鎂合金；阻尼特性；模態(tài)分析；振動(dòng)響應(yīng)
（1. College of Mechanical Engineering, Chongqing University, Chongqing 400030, China;
2. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400030, China;
3. Chongqing Jianshe Motorcycle Co. Ltd., Chongqing 400050, China）
Abstract:The modal parameter identification was contrastively carried out to test the components of AZ91D magnesium alloy and A380 aluminum alloy with the same structure. The structural dynamics properties of the test pieces were researched by modal parameter identification based on the LMS PolyMax method, and the vibration damping capacity of AZ91D magnesium alloy was evaluated by frequency response function and further investigated by vibration response testing at several characteristic points on the test pieces. The results show that the two kind materials with the same geometry structure have the similar natural frequency and principle mode, and the test pieces of AZ91D Mg alloy have higher modal damping ratios. However, the outstanding vibration damping capacity of magnesium alloys can not be exhibited only by material replacement rather than structural redesign because of the lower stiffness of magnesium alloys.
Key words: magnesium alloy; damping capacity; modal analysis; vibration response
