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基于闭式解算法的粘弹性振子系统阻尼效应分析 被引量:2
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作者 孙宝 张文超 +1 位作者 李占龙 秦园 《兵器装备工程学报》 CAS 北大核心 2020年第12期166-170,共5页
为了降低大型工程车辆在工作时产生的噪声及振动,以具有流体特性的Maxwell分数阶粘弹性振子作为研究对象,构建粘弹性阻尼缓冲模型。依据粘弹性材料的分数阶本构关系及动力学关系,建立分数阶数学模型,得到系统的动力学方程。并将离散后的... 为了降低大型工程车辆在工作时产生的噪声及振动,以具有流体特性的Maxwell分数阶粘弹性振子作为研究对象,构建粘弹性阻尼缓冲模型。依据粘弹性材料的分数阶本构关系及动力学关系,建立分数阶数学模型,得到系统的动力学方程。并将离散后的Grünwald-Letnikov分数阶微分定义代入系统方程,得到系统的闭式解。对比分析正弦函数和单位冲激函数两种激励下系统参数变化对阻尼效应的影响。结果表明:微分方程的阶数及系数变化均对系统的阻尼效应产生不同程度的影响。该数值方法为工程车辆中粘弹性缓冲结构的阻尼效应分析提供了一种新的思路。 展开更多
关键词 粘弹性振子 分数阶微分方程 闭式解算法 数值解 缓冲减振
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Joint inversion method for interval quality factor based on amplitude and phase information 被引量:1
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作者 Cao Dan-Ping Li Yue +1 位作者 Sun Wen-Guo Liang Kai 《Applied Geophysics》 SCIE CSCD 2019年第2期199-208,253-254,共12页
Estimating the quality factor Q accurately signifi cantly improves the seismic data resolution and reservoir characterization.The commonly used log-spectral ratio method uses least-squares fi tting to obtain Q values ... Estimating the quality factor Q accurately signifi cantly improves the seismic data resolution and reservoir characterization.The commonly used log-spectral ratio method uses least-squares fi tting to obtain Q values and involves only the amplitude information of seismic data while neglecting phase information.This paper proposes a joint interval Q inversion method based on the spectral ratio method and employs both amplitude and phase information to improve the accuracy.Based on the assumption that Q is independent of frequency,the nonlinear relation between the Q value and the two types of information is jointly used to construct an objective function,which clarifies the quantitative relation between amplitude spectrum,phase information,and Q value.The interval Q value can be inverted by calculating the minimum value of the objective function.The model test exhibits that the proposed method has higher precision and stability than the spectral ratio method;furthermore,the application to field data demonstrates that accurate Q inversion results are consistent with reservoir characteristics. 展开更多
关键词 viscoelastic medium quality factor AMPLITUDE PHASE
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