NEW METHOD FOR VIBRATION MEASUREMENT AND CONTROL OF MOVING WIRE

ＮＥＷＭＥＴＨＯＤＦＯＲＶＩＢＲＡＴＩＯＮＭＥＡＳＵＲＥＭＥＮＴＡＮＤＣＯＮＴＲＯＬＯＦＭＯＶＩＮＧＷＩＲＥＨｕＸｕａｎｌｉ；ＣｈｅｎＴｉａｎｎｉｎｇ；ＴａｎｇＹｏｎｇｊｉｅ；ＺｈａｎｇＳｈｅｎｇｂｉ（Ｘｉ＇ａｎＪｉａｏｔｏｎｇＵｎｉｖｅｒｓｉｔｙ）...     

NEW MULTIOBJECTIVE SIMULATED ANNEALING ALGORITHM AND ITS APPLICATION TO TURBINE CASCADES’ DESIGN

０ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｍｕｌａｔｅｄａｎｎｅａｌｉｎｇａｌｇｏｒｉｔｈｍｉｓａｋｉｎｄｏｆｅｆｉｃｉｅｎｔａｌｇｏｒｉｔｈｍｐｒｏｐｏｓｅｄｉｎｒｅｃｅｎｔｙｅａｒｓｆｏｒｓｏｌｖｉｎｇｌａｒｇｅｓｃａｌａｒｃｏｍｂｉｎａｔｏｒｉａｌｏｐｔ...     

NEW HMM ALGORITHM FOR TOPOLOGY OPTIMIZATION

0 INTRODUCTIONTwo types of algorithms are currently widely used instructure optimization. The first one is the optimization criteria(OC) method. The OC method can be understood directly, but it isdifficult to deduce different types of optimization criteri…     

FATIGUE RELIABILITY DESIGN AND ESTIMATION METHOD FOR VARIABLE LOADING

ＦＡＴＩＧＵＥＲＥＬＩＡＢＩＬＩＴＹＤＥＳＩＧＮＡＮＤＥＳＴＩＭＡＴＩＯＮＭＥＴＨＯＤＦＯＲＶＡＲＩＡＢＬＥＬＯＡＤＩＮＧ＂ＦＡＴＩＧＵＥＲＥＬＩＡＢＩＬＩＴＹＤＥＳＩＧＮＡＮＤＥＳＴＩＭＡＴＩＯＮＭＥＴＨＯＤＦＯＲＶＡＲＩＡＢＬＥＬＯＡＤＩＮＧ＂Ｘ...     

TREATMENT OF COMPLEX LOAD HISTORY AND CONSTRUCTION OF FATIGUE LOAD SPECTRUM

ＴＲＥＡＴＭＥＮＴＯＦＣＯＭＰＬＥＸＬＯＡＤＨＩＳＴＯＲＹＡＮＤＣＯＮＳＴＲＵＣＴＩＯＮＯＦＦＡＴＩＧＵＥＬＯＡＤＳＰＥＣＴＲＵＭＴＲＥＡＴＭＥＮＴＯＦＣＯＭＰＬＥＸＬＯＡＤＨＩＳＴＯＲＹＡＮＤＣＯＮＳＴＲＵＣＴＩＯＮＯＦＦＡＴＩＧＵＥＬＯＡＤＳＰＥ...     

ALGORITHM FOR SPHERICITY ERROR AND THE NUMBER OF MEASURED POINTS

The data processing technique and the method determining the optimal number of measured points are studied aiming at the sphericity error measured on a coordinate measurement machine (CMM). The consummate criterion for the minimum zone of spherical surface is analyzed first, and then an approximation technique searching for the minimum sphericity error from the form data is studied. In order to obtain the minimum zone of spherical surface, the radial separation is reduced gradually by moving the center of the concentric spheres along certain directions with certain steps. Therefore the algorithm is precise and efficient. After the appropriate mathematical model for the approximation technique is created, a data processing program is developed accordingly. By processing the metrical data with the developed program, the spherical errors are evaluated when different numbers of measured points are taken from the same sample, and then the corresponding scatter diagram and fit curve for the sample are graphically represented. The optima! number of measured points is determined through regression analysis. Experiment shows that both the data processing technique and the method for determining the optimal number of measured points are effective. On average, the obtained sphericity error is 5.78μm smaller than the least square solution, whose accuracy is increased by 8.63%; The obtained optimal number of measured points is half of the number usually measured.     

WVAELET TRANSFORM IN TANDERN WITH AUTOREGRESSIVE TECHNIQUE FOR MONITORING AND DIAGNOSIS OF MACHINERY①

ＷＶＡＥＬＥＴＴＲＡＮＳＦＯＲＭＩＮＴＡＮＤＥＭＷＩＴＨＡＵＴＯＲＥＧＲＥＳＳＩＶＥＴＥＣＨＮＩＱＵＥＦＯＲＭＯＮＩＴＯＲＩＮＧＡＮＤＤＩＡＧＮＯＳＩＳＯＦＭＡＣＨＩＮＥＲＹ①ＨｅＺｈｅｎｇｊｉａ；ＺｈａｏＪｉｙｕａｎ；ＭｅｎｇＱｉｎｇｆｅｎｇ（Ｘｉ...     

RELIABILITY AND OPTIMIZATION DESIGN OF NEW ROLLER ORIENTATION CLUTCH

0 INTRODUCTION1It is difficult to manufacture the spring of commune roller orientation clutch. When clutch works, roller often invades the spring space, which make the clutch have no direction. In addition roller's being worn-out and broken may affect the life of clutch[1] According to these circam-stances, we have designed a new roller clutch. The clutch has no springs and acquired Chinese patent, and has made a lot of samples.There are some defects in the conventional method of the des…     

AUTONOMOUS STRUCTURAL HEALTH MONITORING—PART I: MODAL PARAMETER ESTIMATION AND TRACKING

A growing interest for techniques and systems allowing the early detection and monitoring of damage based on vibration analysis is clearly present in different research and application areas, such as civil constructions, mechanical systems, and aircraft and aerospace industry. However, an important element for the applicability of modal-based damage assessment techniques in practice is the automation of the identification and tracking procedure.In this contribution it is shown that, by using a frequency-domain maximum likelihood estimator, features such as high accuracy and confidence bounds for the estimated parameters and robustness for high measurement noise levels create the possibility to automate the modal identification process. For the validation of the model, criteria based on a statistical approach were developed in addition to the well-known criteria such as modal phase colinearity and mode complexity, while the final mode selection is done by means of a fuzzy clustering algorithm. At the same time, an accurate mode-tracking algorithm is presented. It is shown that the problem of coinciding poles, due to shifting or crossing modes under changing structural dynamics, can hamper the mode tracking and a robust solution is proposed. The possibilities and limitations of the automated approach are investigated and tested for a slat track of an Airbus A320 commercial airplane, providing a preliminary study for future monitoring practices during life cycle tests on slat tracks.     

NEW SCALING METHOD FOR COMPRESSOR MAPS USING AVERAGE INFINITESIMAL STAGE

The estimation of the precise performance of existing multistage axial-flow compressors of gas turbine engines is fast becoming a great concern, as the use of gas turbine engines in the power generation and in the military industry increases. In order to reduce the analysis performance error of the traditional scaling method, a new scaling method for estimating the characteristics of multistage axial flow compressors is proposed. This novel method is based on experimental and partial data provided by engine manufacturers. Taking the effect of density-change into account, we introduce the average infinitesimal stage concept, and thereby divide the compression process into an infinite number of infinitesimal processes corresponding to infinitesimal stages. Subsequently, we adopt the corrected Reynolds analogy method for compressible flow calculation in order to ensure much better compliance with the similarity criterion. Validation checks show that the proposed method has enough precision to predict the off-design performance characteristics of multistage axial flow compressors.     

基于人工材料密度的新型拓扑优化理论和算法研究

对基于人工材料密度的拓扑优化理论作了深入分析;推导出了一种基于人工材料密度的拓扑优化准则算法,将该算法应用于拓扑优化的计算中,并给出了基于人工材料密度的拓扑优化迭代分析流程;提出了一种卷积因子方法,用于消除拓扑优化计算结果中易出现的棋盘格式和多孔材料现象;通过数值计算验证了理论和算法的有效性;分析讨论了不同优化参数对拓扑优化计算结果的影响。     

疲劳载荷的平均处理及再现

以300t转炉吹炼时耳轴的实测切应力为例, 通过分析载荷幅值和均值的统计特性, 提出了一种随机疲劳载荷的平均处理方法, 并使用Monte carlO法实现了平均载荷的再现。     

刀具扫描体生成新算法及在数控加工仿真中的应用

介绍一种新的刀具扫描体生成算法。通过将运动物体外表面上的点分成入点、出点和切点 ,新算法能够迅速找到某一时刻运动物体外表面上的切点而形成扫描体 ,从而不依赖于以往扫描体生成的包络法 ,避免求解复杂的方程 ,因而具有方法简单 ,编程容易 ,运算速度快等优点。虽然该算法是针对刀具扫描体生成开发的 ,但它适用于任何回转体扫描体的形成。     

旋转机械同源数据全信息倒频谱分析与应用

提出一种基于旋转机械同源数据融合的全信息倒频谱（full information cepstrum,FIC）分析方法。研究旋转机械同源信息融合的转子回转能量谱,并在此基础上研究全信息倒频谱分析方法。成功地将全信息分析理念拓展到频域分析以外的分析领域,将其应用于高速旋转动力齿轮的故障诊断,取得明显的效果。     

一种随机变化载荷的疲劳损伤累计方法

讨论随机载荷下构件寿命分析时的一种材料损伤计算方法.与通常采用恒幅数据计算变幅疲劳寿命的循环计数统计方法不同,这里针对载荷变程进行损伤计算.作为更一般性的技术,可以对载荷的任一变化即时计算材料发生的损伤结果.为构件局部材料的寿命分析和裂纹行为计算提供一种有效的方法,因为在进行逐个载荷变化的损伤模拟计算时,处于这些部位的应力与构件总体受力情况往往不同,而且与载荷变化的序列有关.     

机械加工过程模糊控制系统的模糊化新方法及其控制算法研究

提出并研究了一种模糊化新方法及其控制算法。该模糊化新方法,具有2m（m可以足够大）个通用的模糊变量且具有通用的隶属函数;由此所建立的模糊控制算法,具有4m2条推理规则,且这4m2条推理规则可由一个算式统一地显式地表述出来,因而具有通用、简洁等特点,可方便地应用于机械加工过程模糊控制系统中。     

离散频谱能量重心法频率校正精度分析及改进

研究噪声对离散频谱能量重心法的频率校正精度的影响,推导了在高斯白噪声背景下用能量重心法对加对称窗的离散频谱进行校正的频率误差理论公式,分析找错和找对最大值谱线情况下的理论误差和某些情况下校正误差较大的原因,为了提高能量重心校正法的频率校正精度,提出用谱线间相位差为阈值作为选择用3条或4条谱线进行校正依据的改进措施。通过对加Hanning窗的离散频谱进行计算机仿真计算,结果表明在大噪声背景下改进的能量重心校正法有很高的频率校正精度,与理论推导十分吻合,验证了理论推导的正确性,表明改进后的能量重心法具有更高的抗噪性能,扩大了能量重心校正法的工程应用范围。     

FFT+FT离散频谱校正法参数估计精度

研究用FFT谱连续细化傅里叶变换分析法进行离散频谱校正时的参数估计误差。分析无噪声情况下频率﹑相位﹑幅值的估计误差随细化倍数的变化规律,估计精度随细化倍数的增大而提高,当细化倍数大于40时,最大估计误差几乎可忽略不计。在高斯白噪声的影响下,细化后频谱序列最大值找错的概率随细化倍数的增加而增加,综合考虑频率分辨率对频率估计精度的影响及频谱序列最大值找错的概率,提出用归一化频率估计综合误差和归一化频率估计最大可能误差两个指标评价此校正法对频率的估计精度,并基于此给出不同信噪比条件下的最优细化倍数。采用非线性最小二乘拟合法对噪声影响下的FFT谱连续细化傅里叶变换分析校正法进行改进,通过仿真模拟验证改进后该校正方法具备更高的校正精度和抗噪能力。     

A NEW ALGORITHM FOR ELIMINATING PHASE-SHIFT ERROR IN PHASE SHIFTING INTERFEROMETRY

０ＩＮＴＲＯＤＵＣＴＩＯＮＰｈａｓｅｓｈｉｆｔｉｎｇｉｎｔｅｒｆｅｒｏｍｅｔｒｙ（ＰＳＩ）ｆｏｒｔｈｅｍｅａｓｕｒｅｍｅｎｔｏｆｓｕｒｆａｃｅｐｒｏｆｉｌｅｉｓａｗｅｌ－ｄｅｖｅｌｏｐｅｄｔｅｃｈｎｉｑｕｅ,ｗｈｉｃｈｈａｓｔｈｅａｄｖａｎｔａｇｅ...