基于光学畸变要求的注射成型透明平板应力翘曲分析

研究了注射成型翘曲应力计算模拟对成型透明件光学畸变预测的意义.首先建立了残余应力计算模型和翘曲计算模型,采用了HsCAE软件的相应模块,对透明平板注射过程中的残余应力、翘曲变形及收缩进行了分析.结果表明,平板边缘的残余应力和厚向收缩大而且不均;而中间区域的残余应力和厚向收缩率小且比较均匀;平板中间区域的翘曲变形量最大,且沿平板平面向四周均匀递减.实测了注射成型平板的外形尺寸,验证了模拟结果.光学畸变测试表明,计算模拟显示残余应力和厚向收缩分布不均的区域光学畸变相对严重,而残余应力和厚向收缩均匀的区域具有低光学畸变;翘曲变形均匀也有利于获得低光学畸变,从而显示了翘曲应力的计算模拟对光学畸变预测的指导意义.     

纤维缠绕气瓶设计分析

讨论了具有金属内衬的纤维缠绕气瓶在加压和卸压过程中的变形特性。依据网格理论,给出了纤维缠绕壳体的设计方法。对塑性性能良好的金属材料内衬,可用强度理论中的最大正应变准则进行强度设计。推导出气瓶卸压时内衬不失稳所应满足的条件。为使卸压时内衬不失稳,内衬与纤维缠绕壳体之间应有足够的粘接强度,而且内衬的壁厚应越薄越好。对壁厚较薄的内衬,给出了气瓶卸压时内衬不失稳的最小粘接强度的确定方法。算例表明,文中给出的设计分析方法,可用于具有金属内衬纤维缠绕气瓶的初步设计。     

具有高精度的永磁容错电机非线性电感分析及其解析式求取

 以六相十极永磁容错电机（FTPMM）为例,通过对电机中磁力线分布的分析,得出FTPMM绕组自感的各个主要组成部分,即激磁感、谐波漏感、槽口漏感和槽内漏感,并分析出FTPMM的大电感是通过增加槽口漏感和谐波漏感来实现的。为提高电机优化设计的正确性,提出了新的磁路模型,并引入槽口磁压降参数和槽口计算厚度参数,得出了具有高精度的非线性绕组自感及其组成部分的解析式。最后通过有限元法(FEM)及实验验证,该解析式的精度在13%以内,并且电机具有很强的容错能力,对永磁容错电机的优化设计和性能分析有理论指导意义。     

参数控制在高精度数控缠绕系统中的实现

介绍了质量相关参数控制在数控缠绕系统中的应用,以及在LabWindows/CVI平台上开发高精度模块化参数监控软硬件系统的具体实现。     

纤维缠绕复合材料结构可靠性评估方法及其应用

为了更加科学有效地评估纤维缠绕复合材料结构的可靠性,根据复合材料渐进失效特点,应用结构系统可靠性理论和方法,将复合材料视为连续体的结构系统,基于复合材料有限元模型对"单元"和"系统"进行了定义,构建了概率渐进失效分析的基本流程,提出了主要失效序列和结构整体的失效概率的精确解算式和近似计算方法.为解决复杂结构系统主要失效...     

Dynamics modeling and pressure control of composites tape winding system based on LQSMC

Pressure fluctuations during the composite fiber winding process seriously affect the product's compactness strength, fatigue resistance, stress uniformity, and resin content. The accuracy of pressure control systems is affected by nonlinear disturbances, such as friction, parameter perturbation, and measurement noise. A robust control algorithm based on linear quadratic optimal control and sliding mode control (LQSMC) is proposed to overcome these problems. The method is based on the system state space expression and linear quadratic optimal control. The state space model of the system is improved by using a Kalman filter and control input for state estimation, and a new sliding surface equation is defined. The ameliorated control algorithm exhibits good performance and can effectively suppress sliding mode control (SMC) chattering. Simulation and experimental results show that LQSMC offers high control precision, much stronger anti-interference, and robustness, which can effectively improve the positioning and tracking accuracy of a pressure control system compared with linear quadratic optimal control (LQC). The winding pressure control precision is improved by 45% to 50%. The results show that the porosity of composite fiber tape winding products decreased thanks to our method.     

Spatio-temporal variability of the wet component of the troposphere – Application to satellite altimetry

Due to the presence of water vapour and cloud liquid water in the atmosphere, the wet component of the troposphere is responsible for a delay in the propagation of the altimeter signals, the Wet Path Delay (WPD). The high space–time variability of the water vapour distribution makes the modelling of WPD difficult, its effect still being one of the main error sources in satellite altimetry applications, e.g. in the estimation of Mean Sea Level (MSL). The understanding and the quantification of the WPD variability on various spatial and temporal scales are the main purposes of this study, in view to improve the MSL error budget. The dominant timescales of WPD variability and its correlation with Sea Level Anomaly (SLA) are examined. In these analyses, the atmospheric reanalysis ERA-Interim model from the European Centre for Medium-Range Weather Forecasts (ECMWF) is used to derive a global dataset of daily grids of WPD, spanning a 28-year period from January 1988 to December 2015. The Seasonal-Trend decomposition procedure based on Loess (STL) is used to extract precise WPD annual and interannual signals. Linear trends have been derived from the interannual time series and the contribution of each STL component was mapped globally, allowing the understanding of the WPD variability in spatial terms. The correlation between SLA and WPD is mapped and decomposed into seasons using monthly mean grids, for a period of 21-years, from January 1993 to December 2013.Aiming at inspecting the sensitivity of the results to the used data set, the WPD temporal analysis is extended to the data set provided by the Special Sensor Microwave Imager (SSM/I) and SSM/I Sounder (SSM/IS) Sensors. The WPD from SSM/I(S) is compared against those from the ERA-Interim and from the National Centers for Environmental Prediction (NCEP).Results show that climate phenomena, especially the El Niño Southern Oscillation (ENSO) are the cause for this high variability, since they affect the water vapour and temperature. The observed trends from ERA-Interim, computed globally and over ocean regions only, allow concluding that WPD is increasing with time by approximately 0.1?mm per year, and the maximum trends are observed for the Pacific North and Indian Oceans. High correlation between WPD and SLA is found over the western tropical Pacific.The comparison between WPD from SSM/I(S) and from ERA-Interim and NCEP, allows concluding that the trends computed using only the SSM/I(S) measurement points are substantially larger.     

双三相永磁同步发电机多目标优化设计

为实现双三相永磁同步发电机(PMSG)的低固有电压调整率、高发电效率和低成本的特性,研究了侧重于降低固有电压调整率的多目标优化设计方案。采用解析法建立单元电机磁链模型,以永磁体磁化方向长度、永磁体所跨弧长和单元电机相绕组匝数为设计变量,分析上述参数对固有电压调整率、发电效率等评价指标的影响,并提出了基于权重系数的多目标优化函数。分别用标准遗传算法(SGA)、差分进化算法(DE)和基于以上2种算法的混合遗传算法(HGA)优化设计参数并进行对比。试验结果表明,HGA优化效果与设计目标具有良好的一致性,与初始设计参数相比,优化后的电机输出能力以及稳压能力均有所改善。     

三相异步电动机不等匝绕组计算软件研究

针对IE4电机开发过程中采用不等匝绕组设计存在的问题,在原三相异步电动机电磁设计软件V2.0版的基础上,开发了能够采用不等匝绕组进行设计计算的新版本软件MEMC V3.0。通过MEMC V3.0在YE4系列、YZTE4系列电机设计中应用。结果表明取得了预期效果。     

月壤原位成型技术工程适用性浅析

月壤原位成型技术作为月球资源原位利用技术体系中的研究热点,是在月表制造建筑材料及实施月表基础设施建设的关键。文章基于国内外月壤原位成型技术发展现状,根据未来可能的月壤成型任务提出了5种月壤成型技术,分析了其各自涉及的成型体性能与任务需求的匹配性,成本及能耗约束,环境适应性以及成型工艺流程的可实现性等;梳理了形成了月壤原位成型领域的发展建议,对于后续月球资源探测和开发具有一定的借鉴和指导意义。