Taguchi DOE实验设计法注射成型工艺参数优化

将CAE技术与DOE技术相结合,可在较少的分析次数下自动获得优化工艺,从而改善注塑制品的质量。以一工业用注塑制品为例,采用Taguchi DOE实验方法进行实验分析,研究了工艺参数对注塑制品体积收缩率变化和翘曲变形的影响,获得的优化工艺参数可使其体积收缩率变化和翘曲变形达到最小。结合CAE模拟分析结果,通过样件试制对优化的工艺参数进行了验证。     

基于CAE和神经网络的注射成型工艺参数优化

通过CAE数值模拟计算,研究了注射成型工艺参数对翘曲变形的影响,以工艺参数为输入参数,以翘曲变形量作为输出参数,构建神经网络模型。以CAE分析结果作为训练样本和校验样本,结合正交实验方法对注塑工艺参数进行优化。这种方法把CAE模拟技术、正交实验技术和神经网络技术有机结合,可以明显缩短优化工艺参数的时间,提高工艺设计效率,能获得比单纯使用正交实验和有限元分析更好的结果。     

基于Moldflow和正交试验设计的注射成型工艺参数的优化

以保护盖为研究对象,采用Moldflow软件对其注射成型过程进行了数值模拟,结合正交试验设计方法,研究了熔体温度、模具表面温度、成型时间、保压时间与保压压力5个工艺因素对塑件体积收缩率和翘曲变形量的影响。通过对模拟结果的信噪比分析和方差分析,获得了各因素的最佳水平,进而获得了最优工艺参数组合。对最优组合工艺参数的注射成型进行模拟试验,验证了采用正交试验设计优化注射成型工艺参数的有效性。     

09MnNiDR钢手工电弧焊工艺参数研究

对09MnNiDR低温钢的手工焊焊接工艺参数及线能量进行研究,以获得合理的工艺参数。     

基于正交试验及MoldFlow模拟优化注塑工艺参数

利用Moldflow有限元分析软件对注塑成型过程进行数值模拟,采用多因素正交试验的方法获得PC/ABS塑料在不同的工艺参数下成型薄壁件的翘曲量,比较了不同工艺参数对翘曲量影响的重要性,并以翘曲变形量为控制目标,通过正交试验等数值计算方法得到优化的工艺参数组合,为注塑工艺优化探索了一种较实用的方法.     

基于数值模拟的汽车外饰件熔接痕分析及其优化设计

采用Moldflow软件对汽车外饰件的熔接痕进行分析,并基于该软件的二次开发原理对熔接痕结果进行量化输出,以量化后的结果作为评价指标,结合正交设计获得了1组最优工艺参数及各工艺参数对熔接痕的影响规律;最后,应用Moldflow软件对最优工艺参数进行验证。     

采用RFR-GA算法的薄壁注塑件质量多目标优化

汽车内饰件可由注塑加工获得,但成型过程中塑件产生的翘曲、体积收缩较大,针对该问题,以某汽车薄壁注塑件为例,研究了其注塑工艺参数的优化方法。通过以注塑过程中的最小翘曲和最小体积收缩率为目标函数,以注塑温度、模具温度、注射压力、保压压力、保压时间以及冷却时间等参数作为设计变量,构建了多目标全局优化模型。利用Moldflow软件结合正交试验获得的试验结果训练随机森林回归模型,采用遗传算法对多目标模型进行全局寻优,获得最佳成型工艺参数,即对其成型缺陷进行了优化。结果表明,所提出的优化方法能够得到全局最优解,并同时优化了该汽车薄壁注塑件的翘曲和体积收缩率。将得到的最佳成型工艺参数进行Moldflow试验,可知翘曲和体积收缩率分别优化了74.6%和42.7%。将获得的最佳注塑成型工艺参数进行生产验证,结果表明生产出的薄壁汽车件成型质量较好,满足生产要求。     

通过复分解法制备磷酸二氢钾的工艺条件优化研究

在磷酸二氢钾的制备过程中,为了获得最优的制备工艺参数,我们采用正交试验的方法对工艺条件进行了优化。讨论了反应温度、时间、终点p H等对磷酸二氢钾产量、磷含量、钾含量的影响顺序以及最优的工艺条件。     

工艺参数对ABS、PP注塑件翘曲变形影响的对比研究

运用Taguchi DOE技术研究了工艺参数对丙烯腈-丁二烯-苯乙烯共聚物(ABS)和聚丙烯(PP)两种材料注塑件翘曲变形的影响,并获得优化的工艺参数以使制品的翘曲变形量最小.以碱性蓄电池盖为例,利用L9(34)正交矩阵进行实验,并采用标准变量分析法(ANOVA)对工艺参数对制品翘曲变形的影响程度进行了对比研究,结果表明:对于两种材料的电池盖,在所选工艺参数中,保压压力和熔体温度对翘曲变形的影响程度最大,获得了最佳工艺参数组合,并预测出在优化工艺参数组合下的最小翘曲量,对注塑生产具有一定的指导意义.     

聚酰亚胺树脂固化动力学参数研究

采用DSC方法研究PMR型的BMP350聚酰亚胺树脂的固化反应过程。用动态方法分析其固化反应特征温度,为确定固化工艺参数提供了依据。采用Kissinger-Ozawa方法进行数据处理,获得了其固化反应动力学参数,建立了该树脂体系的固化动力学模型,结果表明模型与实验数据在固化度低于0.7时拟合效果较好。此模型对合理地研究PMR型聚酰亚胺树脂体系的工艺参数,保证产品质量以及工艺优化提供了必要的前提条件。     

Offline prediction of process windows for robust injection molding

Process parameters play a highly significant role in the final quality of parts produced using dynamic injection molding. Many researches have made great efforts in obtaining an optimum set of process parameters for improving molded part qualities with various optimization methods. However, this work has failed to provide sufficient information to adjust process parameters in the face of variable environmental conditions and various injection machines to ensure robust, high‐quality injection moldings. Current conditions are too cumbersome and require technologists to perform repeated, detailed optimization procedures on the mass production plant floor. An offline method for prediction of process windows is proposed in this article. The process window is significant for robust manufacturing, and optimization of process parameters. Considering that it is an irregular region in a multi‐dimensional space respecting to process parameters, numerical simulations based on DOE method were designed to offline build relationships between process parameters and part qualities. Then the simulation results were classified as positive or negative class, thereby yielding simulation sample data. Finally, the process window was verified using an SVM classifier and a set of simulation samples. Injection molding of an experimental production plate using various process parameters was conducted to verify the reliability of the predicted process window. The results show that, within tolerable deviations, the predicted window of experimental parts is in accordance with verification experiments. The proposed method demonstrates an ability to rapidly obtain a suitable set of process parameters for achieving consistency in part quality with low cost and high efficiency. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40804.     

Femtosecond laser micro-milling dental glass ceramics: An experimental analysis and COMSOL finite element simulation

Dental glass ceramic materials are widely used in all-ceramic restoration technology. In order to effectively solve the problems existing in the process of traditional diamond cutter milling dental glass ceramic materials, such as severe needle loss, large tool wear and general milling efficiency, a new method of ultrafast laser milling dental glass ceramics is proposed. In this paper, 1030 nm femtosecond laser with pulse width of 600fs was used to micro-mill dental glass ceramics. Confocal laser microscopy was used to measure the milling depth and surface roughness of single-layer milling under selected laser processing parameters. The pre-layered milling software was developed to control the z-axis lifting and to compensate the focal length synchronously. Scanning electron microscope (SEM), Raman spectrometer and Vickers micro-hardness tester were used to characterize the dental glass ceramics after femtosecond laser milling. The results showed that under the specific laser processing parameters, the infrared femtosecond laser milling system can achieve a good processing morphology without changing the surface composition and surface hardness of dental glass ceramics. This new dental glass ceramics processing method based on ultrafast laser technique indicated a new direction for further chair processing of dental all-ceramic restoration technology.     

Reconstruction of the Interface Region of Epoxy Polymer-Aluminium Coating Systems in an Aqueous Medium

This paper reports a study of the process of reorganization of the epoxy polymer-aluminium interface during the storage of the coating systems in water. The storage in water first leads to the separation of the system components and then to the restoration of its integrity. As a result, the initial level of adhesion strength is reached or even exceeded. Of all the variable parameters (the solution composition and pH, the sign of the potential applied to the substrate surface, the method of its treatment, the type of hardener used and the conditions of deposition of oligomer from solution and the curing of the system, etc.), temperature was found to have the most significant effect on the rate of the restoration of the adhesion bonds in an aqueous medium. A mechanism of the process was proposed based on the sorption and calorimetric studies of the adhesion systems in an aqueous medium. This mechanism allows for the effect of the electrostatic interactions on the coalescence of the polymer and substrate surfaces with a thin water interlayer between them.     

高效闭式冷却塔的优化设计及节能运行

研究分析了闭式冷却塔设计过程中运行参数的调整优化对换热器换热面积、压降的影响。以降低盘管换热面积、空气外掠管束压降、管程压降为目的,分别控制管内工质流速、喷淋密度、配风量、迎面风速,分析其对换热面积和压降的影响程度,并借助MATLAB数据分析得到最优运行参数。结果表明:盘管错排布置、工质流速1.2 m/s、喷淋密度0.12 kg/(m·s)、配风量175 m3/(kW·h)、迎面风速3.0 m/s时,可以使闭塔的换热面积和压降综合最小,从而达到所设计闭塔的初投资成本和运行费用综合最小。     

气辅注射成型工艺参数正交试验CAE模拟设定

介绍了气辅注射成型中的CAE分析方法;阐述了气辅制品缺陷与工艺参数的关系;运用正交试验方法对待定气辅成型工艺参数进行合理的实验设计,采用塑料成型过程模拟仿真软件MoldflowPlasticInsight5.0对气辅成型塑料周转箱制品进行FLOW-COOL-FLOW分析,代替传统试模方法,并对CAE后处理结果进行综合分析,得到一组优化的工艺参数组合。该组气辅成型工艺参数组合可作为实际生产中的气辅成型工艺参数设定值。     

Identification of relationship between the synthesis/process parameters and properties of a sol–gel‐derived polymer nanocomposite system

A Ti‐containing silicate‐based epoxy‐functional polymer nanocomposite system was synthesized by a sol–gel route with or without the introduction of a reflux process, which was followed by UV‐induced epoxy polymerization. Influences of synthesis and process parameters, including Ti content, sol ageing, reflux process, and UV‐irradiation on various properties of the system were detailed. It was demonstrated that the introduction of a reflux process during the sol–gel synthesis could significantly modify the chemical and physical properties of the resultant material system along with other parameters such as Ti content. Overall results showed that the synthesis and process parameters examined could be employed to modify the microstructure, and to tune the final properties of this polymer nanocomposite system. The technique described herein, therefore, could be used to develop a new process regime to obtain materials of this type with desired properties, which might potentially be employed in certain applications such as dental restoration. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Solid Freeform Fabrication of Permanent Dental Restorations via Slurry Micro-Extrusion

A solid freeform fabrication procedure for human dental restorations via a slurry micro-extrusion process is described. A dental porcelain slurry is developed with pseudoplastic property and moderate viscosity, which permits the slurry to be extruded at low extrusion pressure and have good shape-keeping ability. A green tooth can be produced by this method directly from a CAD digital model in 30 min. The sintering shrinkage of the green tooth is uniform. The microstructure of the sintered tooth is identical to that made via the traditional dental restoration processes. This new dental restoration process presents potential to provide dental patients with better, faster, and less expensive service.     

前馈神经网络与遗传算法相结合解决曲轴中心缩孔

引言缩痕与孔洞是塑件成型时一种常见的缺陷。当制件外层材料冷却固化后,心部材料开始冷却,心部收缩把制件表层拉向制件内部,引起缩痕,如果制件表层的刚度足够大,则将在制件内部产生孔洞而不是缩痕[1]。关于塑件成型过程中的缩痕、翘曲、收缩等缺陷问题,许多学者提出了工艺参数设计的单目标和多目标优化模型,如Kriging模型、BP神经网络、响应面法、支持向量回归等,针对这些模型,采用的优化求解算法主要有:遗传算法、粒子群法、蚁群算法等。申长雨等[2]采用神经网络与混合遗传算法结合优化注塑成型工艺,改善了制品的体收缩     

综放工作面初采前顶板预裂应用研究

为了进一步完善和应用坚硬顶板问题的处理方法,结合郭庄煤矿1305工作面现场条件,采用深孔爆破方法对综放工作面进行初采前顶板预裂。通过对预裂爆破钻孔参数、布置及爆破工艺的优化设计来达到预期的爆破效果。窥视仪对钻孔爆破前后的窥视结果显示：合理的钻孔参数和布置能很好的达到综放工作面初采前顶板预裂效果。初采前顶板预裂不仅很好的解决了坚硬顶板带来的矿压问题,同时还有效提高了顶煤回收率．     

Influence of Water and Supercooling on Permeability and Compressibility of Acrylic Acid Crystal Beds

The performance of a solid‐liquid separation process is often limited by size distribution and morphology of the crystals. To predict the filtration behavior, a robust and applicable model based only on crystallization process parameters is necessary. Therefore, a model has been successfully developed for the industrial system of aqueous acrylic acid melt to predict compressibility and permeability of a crystal bed. For this purpose, common equations are transferred successfully to nonspherical particles. Chord length distributions (CLDs) obtained from an inline focused beam reflectance measurement (FBRM) probe and crystal aspect ratios have been used in combination to determine the major input parameters for the model. Integration of a complex mathematical restoration of crystal size distribution (CSD) from CLD data by the use of existing models is avoided. Considering acceptable fault tolerances of the model, a simple approach used as a robust industrial application is employed. The adjustment of all required constants used in the permeability model was based on simple filtration tests.