包装件振动可靠性的分析和优化需要构建高效准确的车辆随机振动载荷分析模型。该研究将车辆建模为单自由度参数激励系统,分析车辆在平稳载荷下的加速度响应。基于Mathieu方程分析车辆动态响应特性,结果表明,车辆响应中出现少量的大幅振...包装件振动可靠性的分析和优化需要构建高效准确的车辆随机振动载荷分析模型。该研究将车辆建模为单自由度参数激励系统,分析车辆在平稳载荷下的加速度响应。基于Mathieu方程分析车辆动态响应特性,结果表明,车辆响应中出现少量的大幅振动响应的原因是参数激励系统中随机过程β(t)的波动引起了系统的失稳。分别构建车辆在稳态、失稳和衰减条件下的响应分析方法,建立了车辆加速度响应的概率密度函数分析方法,构建了根据记录的试验数据识别系统参数的方法。分析结果表明,该研究建立的车辆随机振动分析方法能够高效准确地再现车辆非平稳随机振动的时域特征及概率密度函数(probability density function,PDF),为研究包装件振动可靠性提供了高效准确的分析基础。展开更多
A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic response...A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm （NExT-ERA） is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.展开更多
文摘包装件振动可靠性的分析和优化需要构建高效准确的车辆随机振动载荷分析模型。该研究将车辆建模为单自由度参数激励系统,分析车辆在平稳载荷下的加速度响应。基于Mathieu方程分析车辆动态响应特性,结果表明,车辆响应中出现少量的大幅振动响应的原因是参数激励系统中随机过程β(t)的波动引起了系统的失稳。分别构建车辆在稳态、失稳和衰减条件下的响应分析方法,建立了车辆加速度响应的概率密度函数分析方法,构建了根据记录的试验数据识别系统参数的方法。分析结果表明,该研究建立的车辆随机振动分析方法能够高效准确地再现车辆非平稳随机振动的时域特征及概率密度函数(probability density function,PDF),为研究包装件振动可靠性提供了高效准确的分析基础。
基金Supported by the National Natural Science Foundation of China（51079027）
文摘A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm （NExT-ERA） is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.
