大跨度结构抗震分析方法及近期进展

对反应谱方法、随机振动方法和时间历程法应用于大跨度结构 抗震分析时的特点作了分析和对比。研究表明，地震地面运动的空间 变化效应(特别是行波效应)对大跨度结构的响应有相当大的影响。反 应谱方法对多点激励地震分析显得相当困难，而随机振动方法则有明 显的优越性。对于强震作用下的大跨度结构非线性地震响应，时间历 程法在现阶段仍应是主要的分析方法。  

基于摩擦声发射信号的磨削表面粗糙度在线检测方法研究

利用摩擦产生的声发射(AE)信号的功率谱密度对磨削表面粗糙度进行在线评价．实测结果表明，AE信号的功率谱密度与外圆磨削表面粗糙度之间存在很好的映射关系，利用随机信号分析的经典估计理论建立的这种映射关系可用于外圆磨削表面粗糙度的在线检测．  

A unified approach to two types of evolutionary random response problems in engineering

Summary Response of structures to earthquake excitations and response of vehicles to road undulations are two typical evolutionary random problems in engineering. Both kinds of the evolutionary random excitations can be regarded as evolved from stationary random excitations, though through two utterly different ways. The former one may be obtained by filtering a stationary random process through a linear time-dependent system, while the latter one may result from nonlinear transformations of the argument of a stationary random process. However, the response problems due to both types of excitations have much in common. By introducing the concept of “evolutionary frequency response”, the expressions of the response evolutionary spectra for both problems can be obtained in a unified, concise way, similar to the input/output PSD relationship in a stationary random problem. For both the evolutionary random problems, the solution procedures are all the same, but the expressions for evolutionary frequency responses are different from each other. Moreover, the evolutionary frequency responses may be interpreted as transient responses of the system subject to certain deterministic evolutionary harmonic excitations. In this sense, an evolutionary random response problem can be reduced to a deterministic response problem. Based on the complex modal analysis, a unified approach to these two response problems is derived here. The method can be applied to any linear time-invariant systems, whether they are symmetrical or not, and whether they are classically damped or not. And the method might be hopefully applied to nonlinear systems, if the statistical linearization technique is accompanied. To the knowledge of the authors, this unified approach to two types of evolutionary random response problems is the first time reported in literature. Received 28 May 1996; accepted for publication 8 January 1997  

论同源随机激励及其响应的特点

本文从一般情形出发，为同源随机激励提出一个含义较广的定义。同源随机激励的特点是其功率谱矩阵可表示为一个列阵与其共轭行阵的乘积。在同源激励作用下，常参数线性系统的响应仍保持激励的上述特点，充分利用这一特点可以节约计算工作量。文中还借助模态分析给出了在同源平稳随机激励下响应功率谱矩阵的解析式，以及在同源演变随机激励下非平稳响应的演变谱表示式。  

大气边界层流场的模拟与大气边界层风洞

动态风荷载测试数据的可靠性依赖于大气边界层流场的正确模拟。本文根据作者在ＦＤ－４大气边界层风洞中，进行大气边界层流场调试时，就如何准确模拟自然风的四个参数方面所积累经验的总结。  

受非均匀调制演变随机激励结构响应快速精确计算

本文假定结构受到非均匀调制的演变随机激励，亦即其调制函数是时间与频率二者的函数，导出了有关的虚拟激励算法，并采用精细逐步积分格式，进行时变功率谱计算，获得了很高的计算效率和精度。  

滚动轴承故障的沃尔什诊断法

本文以沃尔什功率谱为基础提出一种新的故障诊断方法。选取了新的特征量及故障特征系数，并与滤波降噪技术相结合，对３０７滚动轴承进行了诊断。实践证明，这一方法对于冲击故障信号比较有效。  

基于功率谱的爆破地震能量分析方法

针对爆破振动频度-能量分布的定量分析问题，提出了一种基于功率谱的能量分析方法。功率谱密度表征了一定频率谐波分量能量的相对大小，以此为出发点，推导出可以表征爆破振动频度-能量分布的计算方法，结合工程实例的分析结果表明，利用该方法可以实现爆破振动频率构成的定量分析。同时将该方法与目前通用的小波变换能量分析方法作了比较，两者的原理是一致的，但基于功率谱的能量分析方法直接利用频谱分析完成从时域到频域的转化，因此分析过程简便，物理意义明确，更容易理解和掌握。