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基于 Moldflow 的汽车中控台框架翘曲变形分析及优化 被引量:1
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作者 刘巨保 黄建军 +3 位作者 杨明 李峰 张亮 查翔 《塑料工业》 CAS CSCD 北大核心 2024年第3期83-88,共6页
以某汽车中控台框架为研究对象,测量试模样品发现其翘曲变形量超过了装配要求。通过Moldflow软件模拟了该塑件实际的注塑过程,翘曲变形量的模拟值与实测平均值的最大误差为5.98%,发现该塑件翘曲变形的主要因素为冷却不均和收缩不均。本... 以某汽车中控台框架为研究对象,测量试模样品发现其翘曲变形量超过了装配要求。通过Moldflow软件模拟了该塑件实际的注塑过程,翘曲变形量的模拟值与实测平均值的最大误差为5.98%,发现该塑件翘曲变形的主要因素为冷却不均和收缩不均。本文在原物料中添加质量分数为25%的玻璃纤维以及优化工艺参数后,翘曲变形量的模拟值与初始方案相比降低了86.22%。试模验证表明,优化后的翘曲变形量模拟值与实测平均值的最大误差为4.35%,证明了Moldflow软件模拟分析的准确性。试模后各检测点的最大翘曲变形量降到了1.6 mm以下,较优化之前降低了80%以上,为类似大型复杂注塑件的翘曲变形分析及优化提供了思路。 展开更多
关键词 注塑成型 中控台框架 翘曲变形 模流分析 玻璃纤维
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基于Moldex 3D与正交试验的离心泵泵头注塑工艺优化 被引量:2
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作者 李秉辉 张佰城 黄兆阁 《工程塑料应用》 CAS CSCD 北大核心 2024年第1期70-76,共7页
以商用离心泵泵头为研究对象,运用Moldex3D模流分析软件对其注塑成型过程进行了模拟。根据产品的结构特点设置了三种浇口方案,通过对注塑过程的模拟分析选出最佳方案来获得模具设计思路并预测制品成型后可能存在的质量问题。结果表明,... 以商用离心泵泵头为研究对象,运用Moldex3D模流分析软件对其注塑成型过程进行了模拟。根据产品的结构特点设置了三种浇口方案,通过对注塑过程的模拟分析选出最佳方案来获得模具设计思路并预测制品成型后可能存在的质量问题。结果表明,平衡进浇方案的制品具有最好的综合性能,制品的翘曲变形量为1.588 mm,体积收缩率为2.444%。确认最佳浇口方案后,将充填时间(A)、保压时间(B)、冷却时间(C)和模具温度(D)作为实验因素,采用田口法构建五因素四水平的正交试验来获得最佳工艺参数,并使用极差和方差分析对结果进行置信度检测。以翘曲总位移结果为主要权重对象,通过极差分析确定了成型参数的最优组合为A_(1)B_(1)C_(1)D_(1),方差分析则验证了极差分析的结果置信度高于99%。相较于初始方案,制品的翘曲变形量从1.588 mm降低至1.214 mm,降低了23.6%;冷却时间降低至10 s,降低了40%。得知模流分析技术的使用让产品的质量和生产效率都得到了明显的优化,为预测塑件性能、降低生产成本、提高生产效率提供了一种可行的方式。 展开更多
关键词 moldEX3D 正交试验 注塑成型 离心泵 模流分析
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基于Moldflow软件对薄壁件某塑料喷嘴的注塑方案优化研究
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作者 袁志华 符烜赫 袁博 《机械工程师》 2024年第3期14-17,共4页
喷嘴注塑产品的质量和性能很大程度上由注塑方案和工艺参数所决定,不当的注塑方案和工艺参数会导致充填不足、熔接线过多、翘曲变形量大等问题。为了可以减少生产周期,节约生产成本,利用三维软件UG对喷嘴进行建模,基于模流分析软件Moldf... 喷嘴注塑产品的质量和性能很大程度上由注塑方案和工艺参数所决定,不当的注塑方案和工艺参数会导致充填不足、熔接线过多、翘曲变形量大等问题。为了可以减少生产周期,节约生产成本,利用三维软件UG对喷嘴进行建模,基于模流分析软件Moldflow软件对喷嘴注塑产品进行分析和优化,通过比较点浇口和侧浇口两种方案的分析结果,最终确定该产品点浇口的方案更好。并通过设计正交实验,得到优化后的工艺参数。 展开更多
关键词 喷嘴 moldFLOW 模流分析 浇口位置 正交优化
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基于MoldFlow太阳能储能系统下盖成型模拟及应用
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作者 周先保 胡清根 傅海勇 《模具制造》 2024年第2期36-38,共3页
以太阳能储能系统下盖模流分析为例,反复修改流道和浇口截面尺寸与长度以及主流道位置,确定流道尺寸。运用MoldFlow对设计好的流道进行充填分析,以使成型达到流动平衡,并进行冷却、翘曲分析,预测成型缺陷,提出解决措施,为模具设计提供... 以太阳能储能系统下盖模流分析为例,反复修改流道和浇口截面尺寸与长度以及主流道位置,确定流道尺寸。运用MoldFlow对设计好的流道进行充填分析,以使成型达到流动平衡,并进行冷却、翘曲分析,预测成型缺陷,提出解决措施,为模具设计提供浇注系统和冷却系统方案和注射成型工艺参数,并应用于模具设计和实际生产。 展开更多
关键词 太阳能储能系统下盖 流动平衡 成型缺陷
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基于Moldex3D的油漆桶桶盖注塑成型过程分析 被引量:2
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作者 张尧 李章宇 +1 位作者 章金宇 王明伟 《合成树脂及塑料》 CAS 北大核心 2024年第1期62-67,共6页
利用模流分析软件Moldex3D模拟油漆桶桶盖注塑成型过程,研究桶盖模具使用阀式热流道与开式热流道两种不同浇注方案的成型差异,并结合仿真结果设计热流道。通过设计Taguchi DOE实验的因素与水平,优化桶盖产品的注塑工艺参数。结果表明:... 利用模流分析软件Moldex3D模拟油漆桶桶盖注塑成型过程,研究桶盖模具使用阀式热流道与开式热流道两种不同浇注方案的成型差异,并结合仿真结果设计热流道。通过设计Taguchi DOE实验的因素与水平,优化桶盖产品的注塑工艺参数。结果表明:设定工艺参数为熔体温度250℃,保压时间2 s,冷却时间18 s时,产品没有短射、包封等外观质量问题;优化后的注塑工艺参数有效降低了产品的冷却时间。 展开更多
关键词 模流分析软件 moldEX3D 热流道 Taguchi法
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基于Moldflow的排水泵过滤网注塑工艺优化与模具设计 被引量:4
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作者 周俊杰 陈秋凡 +2 位作者 冯文 蒋莹莹 刘朝峰 《工程塑料应用》 CAS CSCD 北大核心 2024年第1期109-115,共7页
利用Moldflow对塑料排水泵过滤网的注塑成型过程进行仿真,通过对其结构分析制定了合理的浇口位置和冷却水路。利用三因素三水平正交试验,研究了熔体温度(A)、充填压力(B)和开模时间(C)对于塑件翘曲变形的影响,得出较优的工艺参数组合为A... 利用Moldflow对塑料排水泵过滤网的注塑成型过程进行仿真,通过对其结构分析制定了合理的浇口位置和冷却水路。利用三因素三水平正交试验,研究了熔体温度(A)、充填压力(B)和开模时间(C)对于塑件翘曲变形的影响,得出较优的工艺参数组合为A_(1)B_(3)C_(3),即熔体温度220℃,充填压力80%,开模时间6 s,此时塑件的最大翘曲变形量为0.632 8 mm,与优化前相比降低了10.37%。最后依据Moldflow的分析结果,利用UG软件对注塑模具的结构进行了设计,根据塑件卡扣的结构特点,型腔采用整体式结构,型芯设计为组合式(主型芯+滑块)结构,并采用三组“斜导柱+滑块”式侧向抽芯机构解决脱模问题。为实现顺序脱模,借助尼龙塞以增加定模板与动模板之间的开模阻力,设计了内置式“小拉杆+拉杆套”结构的定距分型机构;考虑到塑件形状和模具结构与成本,设计了沿塑件侧壁轮廓排布的圆推杆脱模机构;为避免气纹、气穴等缺陷的形成,在型腔处设计了排气槽结构。该模具结构设计较为合理,可为其他结构相似塑件的模具设计提供有益参考和指导。 展开更多
关键词 排水泵过滤网 模流分析 正交试验 注塑成型 模具设计
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基于Moldflow的汽车把手气辅注塑工艺多目标优化 被引量:2
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作者 程佳玮 曹俊哲 +4 位作者 谢传颖 李衡 陈福松 李磊 王小新 《工程塑料应用》 CAS CSCD 北大核心 2024年第4期89-93,共5页
汽车内饰把手是典型的棒状类零件,常采用气体辅助注射成型(GAIM)技术进行生产,以满足把手强度和轻量化要求。由于GAIM技术的成型参数多,塑件成型质量控制难度大,通过运用Moldflow模流仿真分析并结合Taguchi试验方法,以塑件的气体穿透长... 汽车内饰把手是典型的棒状类零件,常采用气体辅助注射成型(GAIM)技术进行生产,以满足把手强度和轻量化要求。由于GAIM技术的成型参数多,塑件成型质量控制难度大,通过运用Moldflow模流仿真分析并结合Taguchi试验方法,以塑件的气体穿透长度和横截面最小壁厚为质量目标来优化成型工艺参数,选择熔体温度、模具温度、气体压力、气体保压时间和预注射量5个主要因素进行正交试验,采用极差分析研究上述5个工艺参数对气体穿透长度和横截面最小壁厚的影响规律,应用多目标综合平衡法得到优化的工艺参数组合,即熔体温度为250℃、模具温度为50℃、气体压力为10 MPa、气体保压时间为10 s、预注射量为75%。通过实际GAIM验证,塑件气体穿透效果良好,满足穿透长度和横截面最小壁厚的要求,塑件质量减轻25%以上,并具有良好的表面质量和尺寸精度,能够显著缩短成型周期,节约塑料材料,提高生产质量和效率,并满足汽车轻量化要求。 展开更多
关键词 气体辅助注射成型 模流仿真分析 Taguchi试验 极差分析 多目标优化
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Irregular initial solidification by mold thermal monitoring in the continuous casting of steels:A review
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作者 Qiuping Li Guanghua Wen +3 位作者 Fuhang Chen Ping Tang Zibing Hou Xinyun Mo 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期1003-1015,共13页
Occasional irregular initial solidification phenomena,including stickers,deep oscillation marks,depressions,and surface cracks of strand shells in continuous casting molds,are important limitations for developing the ... Occasional irregular initial solidification phenomena,including stickers,deep oscillation marks,depressions,and surface cracks of strand shells in continuous casting molds,are important limitations for developing the high-efficiency continuous casting of steels.The application of mold thermal monitoring(MTM) systems,which use thermocouples to detect and respond to temperature variations in molds,has become an effective method to address irregular initial solidification phenomena.Such systems are widely applied in numerous steel companies for sticker breakout prediction.However,monitoring the surface defects of strands remains immature.Hence,indepth research is necessary to utilize the potential advantages and comprehensive monitoring of MTM systems.This paper summarizes what is included in the irregular initial solidification phenomena and systematically reviews the current state of research on these phenomena by the MTM systems.Furthermore,the influences of mold slag behavior on monitoring these phenomena are analyzed.Finally,the remaining problems of the formation mechanisms and investigations of irregular initial solidification phenomena are discussed,and future research directions are proposed. 展开更多
关键词 irregular initial solidification mold thermal monitoring continuous casting mold slag THERMOCOUPLE
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Management of Strawberry Grey Mold Disease Using Biocontrol Agents and Plant Extracts
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作者 P. Sakthi Priya Srushtideep Angidi +2 位作者 Uday Kumar Thera S. V. Nandeesha Thangaswamy Rajesh 《American Journal of Plant Sciences》 CAS 2024年第7期538-551,共14页
Strawberry (Fragaria × ananassa Duch.) is a significant global soft fruit crop, prized for its nutrient content and pleasant flavor. However, diseases, particularly grey mold caused by Botrytis cinerea Pers. Fr. ... Strawberry (Fragaria × ananassa Duch.) is a significant global soft fruit crop, prized for its nutrient content and pleasant flavor. However, diseases, particularly grey mold caused by Botrytis cinerea Pers. Fr. poses major constraints to strawberry production and productivity. Grey mold severely impacts fruit quality and quantity, diminishing market value. This study evaluated five B. cinerea isolates from various locations in the Ri-Bhoi district of Meghalaya. All isolates were pathogenic, with isolate SGM 2 identified as highly virulent. Host range studies showed the pathogen-producing symptoms in the fava bean pods, marigold, gerbera, and chrysanthemum flowers and in the fava bean, gerbera, and lettuce leaves. In vitro tests revealed that neem extract (15% w/v) achieved the highest mycelial growth inhibition at 76.66%, while black turmeric extract (5% w/v) had the lowest inhibition at 9.62%. Dual culture methods with bio-control agents indicated that Bacillus subtilis recorded the highest mean inhibition at 77.03%, while Pseudomonas fluorescens had the lowest at 20.36% against the two virulent isolates. Pot evaluations demonstrated that B. subtilis resulted in the lowest percent disease index at 20.59%, followed by neem extract at 23.31%, with the highest disease index in the control group at 42.51%. Additionally, B. subtilis significantly improved plant growth, yielding an average of 0.32 kg compared to 0.14 kg in the control. The promising results of B. subtilis and neem leaf extract from this study suggest their potential for eco-friendly managing grey mold in strawberries under field conditions. 展开更多
关键词 Strawberry Grey mold BCA Plant Extracts Botrytis cinerea
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Improving Semi-Dried Brown Rice Noodle Quality via Mixed Fermentation of Lactobacillus and Yeast
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作者 LUO Lijuan CHENG Zixuan +6 位作者 QIAO Fan XIONG Gangping LIU Jun HUANG Qingming LI Jiangtao LIN Qinlu LIU Chun 《Rice science》 SCIE CSCD 2024年第5期489-493,I0001-I0005,共10页
To address the coarse texture and poor cooking quality of brown rice flour,we employed fermentation using lactobacillus and yeast in varying proportions.The fermented flour from early indica rice Pear 13 was then proc... To address the coarse texture and poor cooking quality of brown rice flour,we employed fermentation using lactobacillus and yeast in varying proportions.The fermented flour from early indica rice Pear 13 was then processed into semi-dried brown rice noodles. 展开更多
关键词 DRIED COOKING yeast
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Effect of β-Glucan (Angel Yeast) Compared to a Placebo on Cold and Flu Incidence and Symptoms in an Adult Population—A Double Blind, Randomised Controlled Trial
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作者 David Briskey Haibo Zhang +1 位作者 Zhixian Chen Amanda Rao 《Food and Nutrition Sciences》 CAS 2024年第6期484-497,共14页
Background: 1-3, 1-6 β-glucan derived from Baker’s yeast (Saccharomyces cerevisiae) has been widely studied for its immune stimulatory capabilities and safety. Previous studies found β-glucan to have efficacy at re... Background: 1-3, 1-6 β-glucan derived from Baker’s yeast (Saccharomyces cerevisiae) has been widely studied for its immune stimulatory capabilities and safety. Previous studies found β-glucan to have efficacy at reducing incidence of URTIs as well as being a low risk for negative side effects. The current study aimed to examine the effects of yeast β-glucan (Angel Yeast) on cold and flu incidences and symptoms in healthy adults. Methods: Two hundred and thirty-one males and females aged 18 to 65 years old supplemented with either β-glucan or a placebo for 3-months. Participants completed a general health questionnaire every 4 weeks and in addition, if participants experienced any cold or flu symptoms, these were recorded daily (along with severity) until resolved or up to 2 weeks. Results: Supplementation with β-glucan reduced the self-reported severity of sore throats and improved sleep quality compared to the placebo group. Conclusions: Yeast β-glucan supplementation appears to be able to help reduce certain symptoms experienced during a cold or flu episode and is safe and well tolerated. 展开更多
关键词 BETA-GLUCAN COLD FLU Baker’s yeast
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Oxygen variation in titanium powder and metal injection molding
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作者 Junping Shen Chang Liu +7 位作者 Muhammad Dilawer Hayat Jianan Chen Hanqing Tian Fusheng Xin Gang Chen Fei Yang Mingli Qin Xuanhui Qu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第12期2706-2713,共8页
The control of oxygen is paramount in achieving high-performance titanium(Ti)parts by powder metallurgy such as metal in-jection molding(MIM).In this study,we purposely selected the Ti and Ti-6Al-4V powders as the ref... The control of oxygen is paramount in achieving high-performance titanium(Ti)parts by powder metallurgy such as metal in-jection molding(MIM).In this study,we purposely selected the Ti and Ti-6Al-4V powders as the reference materials since these two are the most representative Ti materials in the industry.Herein,hydride-dehydride(HDH)Ti powders were pre-oxidized to examine the ef-fect of oxygen variation on the characteristics of oxide layer on the particle surface and its resultant color feature.The results indicate that the thickness and Ti oxide level(Ti^(0)→Ti^(4+))of the oxide layer on the HDH Ti powders increased as the oxygen content increased,lead-ing to the transition of color appearance from grey,brown to blue.This work aids in the powder feedstock selection at the initial stage in powder metallurgy.In addition,the development of oxygen content was comprehensively studied during the MIM process using the gas-atomized(GA)Ti-6Al-4V powders.Particularly,the oxygen variation in the form of oxide layer,the change of oxygen content in the powders,and the relevant parts were investigated during the processes of kneading,injection,debinding,and sintering.The oxygen vari-ation was mainly concentrated in the sintering stage,and the content increased with the increase of sintering temperature.The variation of oxygen content during the MIM process demonstrates the crucial role of powder feedstock and sintering stage in controlling oxygen con-tent.This work provides a piece of valuable information on oxygen detecting,control,and manipulation for the powder and processing in the industry of Ti and its alloys by powder metallurgy. 展开更多
关键词 titanium alloys OXYGEN metal injection molding powder metallurgy
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Effects of the Water-Cement Ratio and the Molding Temperature on the Hydration Heat of Cement
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作者 代金鹏 HE Jie +1 位作者 WANG Qicai LOU Xuyu 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第4期990-998,共9页
The effects of the water-cement ratio and the molding temperature on the hydration heat of cement were investigated with semi-adiabatic calorimetry.The specimens were prepared with water-cement ratios of 0.31,0.38,and... The effects of the water-cement ratio and the molding temperature on the hydration heat of cement were investigated with semi-adiabatic calorimetry.The specimens were prepared with water-cement ratios of 0.31,0.38,and 0.45,and the molding temperature was specified at 10 and 20℃.The experimental results show that,as the water-binder ratio increases,the value of the second temperature peak on the temperature curve of the cement paste decreases,and the age at which the peak appears is delayed.The higher the water-cement ratio,the higher the hydration heat release in the early period of cement hydration,but this trend reverses in the late period.There are intersection points of the total hydration heat curve of the cement pastes under the influence of the water-cement ratio,and this law can be observed at both molding temperatures.With the increase in the molding temperature,the age of the second temperature peak on the temperature curve of the cement paste will advance,but the temperature peak will decrease.The higher the molding temperature,the earlier the acceleration period of the cement hydration began,and the larger the hydration heat of the cement in the early stage,but the smaller the total heat in the late period.A subsection function calculation model of the hydration heat,which was based on the existing models,was proposed in order to predict the heat of the hydration of the concrete. 展开更多
关键词 semi-adiabatic calorimetry hydration heat water-cement ratio molding temperature MODELING
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Mathematical Modeling of Cell Polarity Establishment of Budding Yeast
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作者 Yue Liu Jun Xie +1 位作者 Hay-Oak Park Wing-Cheong Lo 《Communications on Applied Mathematics and Computation》 EI 2024年第1期218-235,共18页
The budding yeast Saccharomyces cerevisiae is a powerful model system for studying the cell polarity establishment.The cell polarization process is regulated by signaling molecules,which are initially distributed in t... The budding yeast Saccharomyces cerevisiae is a powerful model system for studying the cell polarity establishment.The cell polarization process is regulated by signaling molecules,which are initially distributed in the cytoplasm and then recruited to a proper location on the cell membrane in response to spatial cues or spontaneously.Polarization of these signaling molecules involves complex regulation,so the mathematical models become a useful tool to investigate the mechanism behind the process.In this review,we discuss how mathematical modeling has shed light on different regulations in the cell polarization.We also propose future applications for the mathematical modeling of cell polarization and morphogenesis. 展开更多
关键词 Budding yeast CDC42 MORPHOGENESIS SEPTIN Mathematical models
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Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope
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作者 Qiang Liu Xiang Li +3 位作者 Shen Du Ming Gao Yanbin Yin Jiongming Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期102-110,共9页
During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a rest... During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels. 展开更多
关键词 mold flux low basicity BUBBLES three-dimensional X-ray microscope VISCOSITY
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Influence of nitrogen status on fermentation performances of non-Saccharomyces yeasts:a review
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作者 Jinchen Li Mengmeng Yuan +3 位作者 Nan Meng Hehe Li Jinyuan Sun Baoguo Sun 《Food Science and Human Wellness》 SCIE CSCD 2024年第2期556-567,共12页
Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic fermentation.Such influences are imposed on yeast growth and fermentation performances inclu... Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic fermentation.Such influences are imposed on yeast growth and fermentation performances including the formation of secondary metabolites.Saccharomyces cerevisiae,the main yeast responsible for fermentation,has been studied extensively regarding nitrogen impacts.On the other hand,a similar study for non-Saccharomyces yeasts,whose contributions to winemaking have gradually been acknowledged,remains to be fully explored,with a few studies being reported.This review starts by discussing nitrogen impacts on non-Saccharomyces yeast growth and fermentation kinetics in different case scenarios,then proceeds to summarize the nitrogen preferences of individual yeast strains with regulation mechanisms elucidated by recent studies.Detailed discussions on the influences on the production of volatile compounds and proposed pathways therein are made,followed by future work suggested as the final section.In summarizing the nitrogen impacts on non-Saccharomyces yeasts throughout alcoholic fermentation,this review will be helpful in obtaining a more comprehensive view on these non-conventional wine yeasts in terms of nutrient requirements and corresponding volatile production.Research gaps will therefore be elucidated for future research. 展开更多
关键词 Non-Saccharomyces yeasts NITROGEN Fermentation kinetics Nitrogen preference Wine aroma
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Numerical simulation study on the mold strength of magnetic mold casting based on a coupled electromagnetic-structural method
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作者 Wei-li Peng Jian-hua Zhao +1 位作者 Cheng Gu Ya-jun Wang 《China Foundry》 SCIE EI CAS CSCD 2024年第5期577-587,共11页
The properties of the magnetic mold in magnetic mold casting directly determine the quality of the final cast parts.In this study,the magnetic mold properties in magnetic mold casting,were studied utilizing a coupled ... The properties of the magnetic mold in magnetic mold casting directly determine the quality of the final cast parts.In this study,the magnetic mold properties in magnetic mold casting,were studied utilizing a coupled electromagnetic-structural method through numerical simulation.This study investigated key factors including equivalent stress,the distribution of tensile and compressive stresses,and the area ratio of tensile stress.It compared molds made entirely of magnetic materials with those made partially of magnetic materials.Simulation results indicate that as current increases from 4 A to 8 A,both the initial magnetic mold and the material-replaced magnetic mold initially show an increasing trend in equivalent stress,tensile-compressive stress,and the area ratio of tensile stress,peaking at 6 A before declining.After material replacement,the area ratio of tensile stress at 6 A decreases to 19.84%,representing a reduction of 29.72%.Magnetic molds comprising a combination of magnetic and non-magnetic materials exhibit sufficient strength and a reduced area ratio of tensile stress compared to those made entirely from magnetic materials.This study provides valuable insights for optimizing magnetic mold casting processes and offers practical guidance for advancing the application of magnetic molds. 展开更多
关键词 magnetic mold casting coupled electromagnetic-structural method numerical simulation stress analysis
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Impact of Storage Temperature on Microbial Diversity and Probiotic Effect of Liquid Brewers’ Yeast
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作者 Peter Alphonce Obuong Alaru Alfred Anakalo Shitandi +1 位作者 Symon Maina Mahungu John Muasya Kilumba Muia 《Open Journal of Animal Sciences》 2024年第3期168-182,共15页
Using probiotics as animal feed additives instead of antibiotics is gaining momentum to avert adverse negative effects on human health. Liquid brewers yeast (LBY) is an industrial by-product containing probiotic micro... Using probiotics as animal feed additives instead of antibiotics is gaining momentum to avert adverse negative effects on human health. Liquid brewers yeast (LBY) is an industrial by-product containing probiotic microorganisms and is also used as a protein supplement for dairy animals. Nevertheless, value chain actors lack of appropriate handling practices compromises the by-products quality and safety. This study aimed to determine the effect of variation in temperature on microbial diversity and probiotic effects during the storage time of LBY sampled from distributors and farmers from Githunguri sub-county of Kenya. The samples were stored at 20C, 25C and 30C, then tested on 0, 5, 10, 15 and 20 days. The studys parameters involved determining the pH levels, lactic acid bacteria (LAB), total coliform count (TCC), mould, and yeast in LBY. The rate (k) of the reaction kinetics model was used to extrapolate the expected probiotic shelf life. The LAB and yeast populations were reduced in a first-order reaction at all storage temperatures. The rate of reduction in the numbers of LAB reduced with an increase in temperature (k = 0.019 and 0.023) at 20C and 30C, respectively. Yeasts highest rate of growth reduction was 25C (k = 0.009) and least at 30C (k = 0.043). The minimum effective concentration for probiotics of 106 CFU/mL needed to observe the beneficial physiological impact on farm animals was achieved between 34.9 and 35.5 days at the tested storage temperatures. The study provides insight into the unexploited low-cost probiotic potential of LBY in dairy production. Conversely, handling practices and environmental microbial contamination along the value chain can compromise product quality and safety. There is a need to advocate its use in dairy for improved productivity and sensitize farmers to appropriate hygienic measures along the LBY value chain. 展开更多
关键词 Liquid Brewers’ yeast Microbial Diversity PROBIOTICS Shelf Life
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基于Moldflow的绗缝机夹子注塑模设计
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作者 孙仲辉 姚序 +1 位作者 高贵 殷璟 《模具技术》 2024年第1期26-32,共7页
以绗缝机夹子的短板为例,基于Moldflow有限元分析软件,合理确定了塑件的浇口位置和浇口形式,精确预测出塑件的充型时间、注射压力、锁模力等工艺参数,并分析出塑件的体积收缩率及熔接线、气穴等潜在缺陷的位置。有限元模拟结果为注塑成... 以绗缝机夹子的短板为例,基于Moldflow有限元分析软件,合理确定了塑件的浇口位置和浇口形式,精确预测出塑件的充型时间、注射压力、锁模力等工艺参数,并分析出塑件的体积收缩率及熔接线、气穴等潜在缺陷的位置。有限元模拟结果为注塑成型设备的选型和成型工艺参数的合理制定提供了可靠依据,为模具的优化设计提供了方向。基于Moldflow分析结果,设计出一套一模两腔侧浇口、带斜导柱侧向分型与抽芯机构的注塑模具并一次性试模成功。Moldflow有限元分析软件在注塑模设计中的应用不仅有效降低了模具设计的成本和周期,也为同类零件的模具优化设计提供了参考。 展开更多
关键词 注塑模 moldFLOW 模流分析 一模多腔
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Elimination of cracks in stainless steel casings via 3D printed sand molds with an internal topology structure
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作者 Jun-hang Xu Bao-zhi Li +6 位作者 Zhao-wei Song Yun-bao Gao Jing-ming Li Yu Wang Qiu-lin Wen Heng Cao Zeng-rui Wang 《China Foundry》 SCIE EI CAS CSCD 2024年第4期319-326,共8页
The important supporting component in a gas turbine is the casing,which has the characteristics of large size,complex structure,and thin wall.In the context of existing 3DP sand casting processes,casting crack defects... The important supporting component in a gas turbine is the casing,which has the characteristics of large size,complex structure,and thin wall.In the context of existing 3DP sand casting processes,casting crack defects are prone to occur.This leads to an increase in the scrap rate of casings,causing significant resource wastage.Additionally,the presence of cracks poses a significant safety hazard after the casings are put into service.The generation of different types of crack defects in stainless steel casings is closely related to casting stress and the high-temperature concession of the sand mold.Therefore,the types and causes of cracks in stainless steel casing products,based on their structural characteristics,were systematically analyzed.Various sand molds with different internal topology designs were printed using the 3DP technology to investigate the impact of sand mold structures on high-temperature concession.The optimal sand mold structure was used to cast casings,and the crack suppression effect was verified by analyzing its eddy current testing results.The experimental results indicate that the skeleton structure has an excellent effect on suppressing cracks in the casing.This research holds important theoretical and engineering significance in improving the quality of casing castings and reducing production costs. 展开更多
关键词 gas turbine casing crack defects 3D printed sand mold topological structure high-temperature concession
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