摘要
基于黏弹性阻尼机理,采用热动态机械分析仪(DMA)系统研究了GW63K型高强镁合金的阻尼特性.从动力学应用的角度给出了该型镁合金阻尼的大小、变化规律、影响因素等特征.首次明确了该型镁合金的阻尼参数在动力学分析中应作为变化量来定性描述,并定量地给出了阻尼随服役环境温度、激励频率变化的规律.对动力学系统中考虑变化阻尼而引起的非线性求解问题,建立了阻尼与时间的依赖关系.基于虚拟激励方法构造平稳问题的拟非平稳随机分析方法,提出了考虑镁合金变化阻尼的随机振动高效数值分析方法.分别对镁合金构件的结构动力学响应进行了数值模拟和实验研究以及对比分析验证.结果表明,基于恒定阻尼与变化阻尼的分析结果差异明显,而基于变化阻尼的动力学模型跟实验结果吻合更好.得出了在对精度要求较高的领域,应当采用变化阻尼模型对镁合金材料结构进行动力学分析的结论.
The damping characteristics of the GW63K magnesium alloy were studied by means of the dynamic thermomechanical analyzer(DMA)based on the viscoelastic damping theory.The magnitude,variation characteristics and dependence sensitivity of this magnesium alloy’s damping were given from the angle of dynamic applications.For the first time the damping parameters of this type of magnesium alloy could be qualitatively described as variables in the dynamic analysis,and the damping change laws with the service environment temperature and excitation frequency were quantitatively given.For the nonlinear solution problem with variable damping in the dynamic system,the time-dependent manner of damping was established.Based on the pseudo excitation method,a quasi-non-stationary stochastic analysis method was built for stationary problems,and an efficient numerical analysis method for variable-damping problems of magnesium alloys under random vibration was proposed.Numerical and experimental verifications of the structural dynamic responses of magnesium alloy components were carried out respectively,to reveal the obvious difference between the analysis results based on constant damping and variable damping.The dynamic model based on variable damping gives results in better agreement with the experimental results.It is concluded that in the fields where high accuracy is required,the variable-damping model should be chosen to analyze the magnesium alloy material structure.
作者
徐文涛
张琰辉
唐光武
潘根基
XU Wentao;ZHANG Yanhui;TANG Guangwu;PAN Genji(School of Mechanics and Safety Engineering,Zhengzhou University,Zhengzhou 450001,P.R.China;State Key Laboratory of Bridge Engineering Structural Dynamics,China Merchants Chongqing Communications Technology Research&Design Institute Co.,Ltd.,Chongqing 400067,P.R.China)
出处
《应用数学和力学》
CSCD
北大核心
2020年第12期1297-1310,共14页
Applied Mathematics and Mechanics
基金
河南省科技发展计划基金(182102210178)。
关键词
虚拟激励法
镁合金材料
阻尼特性
动态热机械分析仪
随机振动
pseudo excitation method
magnesium alloy material
damping characteristic
dynamic thermomechanical analyzer
random vibration
作者简介
徐文涛(1980-),男,满族,副教授,博士,硕士生导师(E-mail:xuwt@zzu.edu.cn);通讯作者:唐光武(1963-),男,研究员,硕士(E-mail:tangguangwu@cmhk.com).
