软体防刺复合材料的设计与优化

采用模压成型工艺制备了个体防护装备用软体防刺复合材料, 研究了树脂基体种类、 纤维织物种类和树脂含量对复合材料防刺性能的影响。结果表明, Surlyn树脂体系具有优异的防刺性能; 芳纶织物作为增强材料的复合材料穿刺性能优于UHMWPE织物; 树脂含量对复合材料的防刺性能也有影响, 当树脂的质量分数为47%时, Kevlar/Surlyn复合材料的防刺性能最优。     

软体防刺复合材料的设计与优化

采用模压成型工艺制备了个体防护装备用软体防刺复合材料,研究了树脂基体种类、纤维织物种类和树脂含量对复合材料防刺性能的影响.结果表明,Surlyn树脂体系具有优异的防刺性能;芳纶织物作为增强材料的复合材料穿刺性能优于UHMWPE织物;树脂含量对复合材料的防刺性能也有影响,当树脂的质量分数为47％时,Kevlar/Surlyn复合材料的防刺性能最优.     

石英纤维增强磷酸铬铝/有机硅杂化树脂基复合材料性能

通过甲基三乙氧基硅烷(MTEOS)在磷酸铬铝中水解制备了磷酸铬铝/有机硅的有机-无机杂化树脂,以石英纤维为增强材料,氧化铝为固化剂,采用模压成型工艺制备纤维增强杂化树脂基复合材料.考察了杂化树脂基体以及复合材料的力学、介电性能等,结果表明复合材料的弯曲强度大大提高,介电性能更加优越.     

VARI工艺成型纤维增强树脂复合材料层合板厚度和纤维体积分数的影响因素

分析了影响真空辅助成型技术（VARI）工艺成型复合材料的纤维体积分数和厚度均匀性的关键因素,即VARI成型工艺的树脂流动控制形式、纤维预制体状态、织物状态、树脂黏度,通过试验分析了各因素对VARI成型复合材料厚度和纤维体积分数的影响。试验结果表明,采用HFVI（high fiber-volume vacuum infusion）工艺、BA9914树脂及真空处理后的U3160单向机织物成型的纤维增强树脂复合材料层合板,其纤维体积分数和厚度均匀性能够接近预浸料/热压罐成型的复合材料制件的水平。     

RTM成型工艺对复合材料制品性能的影响

RTM(树脂传递模塑的简称)成型工艺是一种将树脂注入闭合模具中浸润增强材料的复合材料成型工艺。工艺参数对复合材料制品性能有很大的影响。本文对注射压力、注射温度、真空辅助、注胶口和排气口的位置、纤维含量和结构等工艺参数对复合材料制品性能的影响进行了概述。     

连续纤维增强高性能热塑性树脂基复合材料的制备与应用

连续纤维增强高性能热塑性复合材料以轻质高强、良好的抗冲击性能、成型周期短、可二次成型、废料可回收再利用等独特优点,逐渐受到复合材料工业界的关注。本文从常用的几种高性能热塑性树脂基体为起点,对连续纤维增强高性能热塑性复合材料应用现状进行介绍,并详细阐述了连续纤维增强高性能热塑性复合材料的成型及性能研究。在此基础上,从应用需求、成型工艺、材料性能三方面总结了国内连续纤维增强高性能热塑性复合材料的未来发展趋势,以期推动连续纤维增强高性能热塑性复合材料的结构设计和应用。     

纤维增强树脂复合材料网格结构成型工艺研究进展

纤维增强树脂复合材料网格结构具有高比刚度、高比强度、高损伤容限、可自动化成型等特点,在航空宇航结构中有着广阔的应用前景。纤维在网格结构交叉点处的堆积、架空、弯曲和裁剪严重影响了结构的最终性能。针对纤维增强树脂复合材料网格结构交叉点处的固有缺陷,总结了纤维缠绕、铺放、三维编织、互锁、真空辅助树脂传递模塑等工艺在纤维增强树脂复合材料网格结构成型时的优势和不足,同时,探讨了网格结构设计与成型工艺间的关系。分析了目前网格结构研究中的主要问题,并对未来的发展方向进行了展望。     

某复合材料气瓶的缠绕工艺

将连续的纤维经过浸胶后，按照一定的规律缠绕到芯模上，然后再加热或常温固化，制成一定形状制品的工艺方法叫纤维缠绕成型工艺。本文论述了湿法缠绕在环缠绕复合材料气瓶生产中的应用，通过对复合材料增强层、防护层的工艺设计和树脂体系的选择，生产复合材料气瓶23件，通过了各项鉴定试验，满足复合材料高压气瓶的设计要求。     

乙烯基酯树脂复合材料的固化过程研究

复合材料固化是成型过程中关键步骤之一,涉及到模具设计,成型工艺确定等.本文采用等温DSC分别研究了玻璃纤维/乙烯基酯树脂,碳纤维/乙烯基酯树脂复合材料和乙烯基酯树脂的固化过程.结果表明:玻璃纤维的存在加速了乙烯基酯树脂的固化速度,而碳纤维的存在使得乙烯基酯树脂的固化速度变慢,纤维增强材料的存在提高了树脂的固化度.     

复合材料液体成型树脂流动前锋监测技术研究进展

纤维复合材料是一种被广泛应用于航空航天工业的材料。复合材料液体成型(LCM)工艺是一种常见的纤维复合材料制备工艺。而使用LCM工艺生产的纤维复合材料可能会由于超前-迟滞效应产生缺陷,影响纤维复合材料的使用性能。通过监测LCM工艺中树脂流动前锋可以优化树脂注入策略,减少内部缺陷的产生,提升纤维复合材料制成品的质量。本文介绍了光纤传感器监测技术、CCD(电荷耦合器件)摄像机监测技术、热电偶监测技术、压力传感器监测技术和超声传感器监测技术这五种树脂流动前锋监测技术的国内外研究现状,并重点介绍了超声传感器监测技术主要使用的两种监测方法,即超声纵波监测法和超声Lamb波监测法。最后,分析总结了在纤维预成型体中树脂流动前锋超声监测系统研究中目前存在的难点以及未来的发展方向。     

Economic‐Statistical Design of the Synthetic Chart with Estimated Process Parameters

In this paper, the effects of process parameter estimation on the cost of the synthetic chart are studied. We study the increase in cost when the optimal chart's parameters corresponding to the known process parameters case are used to estimate the cost when the process parameters are actually just estimated. By studying the increase in cost, practitioners will be able to determine whether the optimal chart's parameters, computed based on known process parameters, can still be used to reliably estimate the cost when the target values of the process mean and variance are estimated. We also look at the minimum number of preliminary subgroups needed for the estimation of process parameters so that the cost for the estimated process parameters case is almost the same as the cost for the known process parameters case. Furthermore, we also look at the cost savings, in the case of process parameter estimation when the optimal chart's parameters are computed based on estimated process parameters, instead of adopting the chart's parameters corresponding to known process parameters. This enables practitioners to determine the cost advantages of selecting the chart's parameters that minimize the cost when process parameters are estimated, instead of adopting the optimal charting parameters corresponding to the case of known process parameters. Copyright © 2014 John Wiley & Sons, Ltd.     

复杂钣金零件充液拉深工艺分析与试验研究

目的研究复杂钣金零件充液拉深的成形性能,以代替传统的落压成形工艺。方法采用有限元方法对成形过程进行模拟,分析各工艺参数对零件成形质量的影响,以及起皱、破裂等缺陷出现的原因和避免方法,并获得合理的工艺参数范围。以仿真结果为依据,设置工艺试验的初始参数,对该复杂钣金零件进行充液成形试验,以验证工艺可行性。结果有限元仿真对成形过程中的起皱和破裂缺陷预测准确,并给出了可行的工艺参数范围;通过成形试验,验证了工艺参数的合理性,获得了合格零件。结论充液拉深工艺可以明显改进零件的成形性能,反胀压力、最大液室压力等是充液拉深工艺的重要参数,直接影响着充液拉深过程的成败。     

Intelligent process design system for the transfer moulding of electronic packages

Currently, mould design and the setting of the process parameters of transfer moulding for electronic packages are done manually in a trial-and-error manner. The effectiveness of the setting of parameters is largely dependent on the experience of engineers. The paper describes an intelligent process design system for transfer moulding of electronic packages that is used to determine optimal mould design parameters and the setting of the process parameters mainly based on case-based reasoning, artificial neural networks and a multiobjective optimization scheme. The system consists of two modules: a case-based reasoning module and a process optimization module. The former module is used to determine initial mould design parameters and the setting of the process parameters while the latter module is used to determine optimal mould design parameters and the setting of the process parameters. Implementation of the intelligent system has demonstrated that the time for the determination of optimal mould design parameters and the setting of the process parameters can be greatly reduced, and the setting of parameters recommended by the system can contribute to the good quality of moulded packages.     

喷印工艺控制参数对水性油墨墨滴形态的影响

目的为了提高水性油墨的喷墨印刷质量,通过控制喷印工艺参数以获得良好的墨滴形态。方法分析喷印工艺控制的关键参数以及墨滴形态的表征参数,通过单因素工艺参数对墨滴形态影响的实验,分析电压、点火频率和脉冲宽度对墨滴形态各评价指标的影响程度,并运用AHP法构建墨滴形态的质量分析模型;通过多因素工艺参数组合对墨滴形态影响的正交实验,分析各工艺参数与墨滴形态参数之间的关联性,并结合质量评价模型综合评判喷印工艺参数对墨滴形态的影响。结果喷印工艺参数电压、点火频率和脉冲宽度共同影响墨滴形态的质量,脉冲宽度对其影响最大,点火频率次之,电压的影响程度最小,其权重分别为0.462,0.272,0.266。结论水性油墨喷印工艺中,通过合理地控制喷印工艺的关键参数,可以有效地提高墨滴形态质量,从而获得良好的印刷品质量。     

Optimization of aluminium sheet hot stamping process using a multi-objective stochastic approach

This article aims to investigate the means to obtain optimal hot stamping process parameters and the influence of the stochastic variability of these parameters on forming quality. A multi-objective stochastic approach, integrating response surface methodology (RSM), multi-objective genetic algorithm optimization non-dominated sorting genetic algorithm II (NSGA-II) and the Monte Carlo simulation (MCS) method is proposed in this article to achieve this goal. RSM was used to establish the relationship between the process parameters and forming quality indices. NSGA-II was utilized to obtain a Pareto frontier, which consists of a series of optimal process parameters. The MCS method was employed to study and reduce the influence of a stochastic property of these process parameters on forming quality. The results confirmed the efficiency of the proposed multi-objective stochastic approach during optimization of the hot stamping process. Robust optimal process parameters guaranteeing good forming quality were also obtained using this approach.     

Utilization of neural networks for the recognition of variance shifts in correlated manufacturing process parameters

Traditional statistical process control (SPC) charting techniques were developed for use in discrete industries where independence exists between process parameters over time. Process parameters from many manufacturing industries are not independent, however, but they are serially correlated. Consequently, the power of traditional SPC charts was greatly weakened. The paper discusses the development of neural network models to identify successfully shifts in the variance of correlated process parameters. These neural network models can be used to monitor manufacturing process parameters and signal when process adjustments are needed.     

基于 AHP 与灰色系统理论的隔热件成形回弹控制优化

目的汽车隔热件的冲压成形过程比较复杂,成形工艺参数较多,实际生产难以准确地建立起工艺参数与质量目标之间的联系,研究工艺参数对成形质量及回弹的影响为实际生产提供指导必要而有意义。方法对模具间隙、凹模圆角半径、摩擦因数等影响回弹的因素进行正交试验,设计了试验方案,获得了成形零件的回弹数据;结合层次分析理论(APH)计算了成形工艺参数对多质量目标的权重,最后利用灰色系统理论,计算出了成形质量相对目标函数的关联度,再进行进一步计算获得各成形工艺参数的平均关联度,将优化后的工艺参数应用于有限元仿真与实验验证。结果通过层次分析理论和灰色系统理论对成形工艺参数进行优化,获得了优化工艺参数组合,隔热件成形质量明显提高,回弹量控制在较小范围内。结论当模具间隙为0.805 mm、凹模圆角半径为12 mm、摩擦因数为0.125时,回弹前后距离差Δd=0.918 mm、回弹前后夹角差Δα=0.340°,回弹得到有效控制。     

二步法方型三维编织预制件编织结构参数与工艺参数

以比较真实的细观结构为基础,本文作者运用"单元体叠加法",通过具体推导编织结构参数和工艺参数之间的关系,提出一套准确的编织工艺计算公式用于指导实际生产的工艺设计。同时,进行了许多设计的实验,有效地验证了所得到的结构参数和工艺参数之间关系的正确性。     

An Experimental Investigation and Analysis of PTAW Process

Experiments are conducted to deposit SS304 L powders on SS316 plates by plasma transfer arc welding process with varying four input process parameters, namely scanning speed, powder feed rate, stand-off distance, and current. The effects of these four input process parameters on deposition geometry, dilution, and bead continuity are investigated in this study. Attempts have been made to explain the experimental results with only two compound parameters, “energy deposition per length” and “powder deposition per length” instead of four independent input process parameters. It is observed that the variation of dilution is very little when the scanning speed increases from 100 to 600 mm/min and other process parameters remain constant. When the powder feed rate increases and other parameters remain constant, initially the dilution decreases rapidly and attains a minimum value which do not change further with increase in powder feed rate. It is also observed that the dilution remains almost constant around 6–9% as the stand-off distance changes from 7 to 11 mm and other process parameters remain constant. The formation of nonuniform bead is found to be due to insufficient energy deposition per length per mass of supplied powder.     

径-轴双向环轧工艺的研究进展

回顾了环件径-轴双向轧制锻透条件、咬入条件、刚度条件等相关理论研究进展,分析了工艺参数对轧制过程的影响及其确定准则,在此基础上引入轧制曲线的概念,并给出了径-轴双向环轧轧制曲线的设计原则,还探讨了在利用有限元方法模拟轧制过程、优化轧制工艺参数时存在的问题,并给出了对数值模型进行控制和处理的有效方法。