Fundamentals and Processes of Fluid Pressure Forming Technology for Complex Thin-Walled Components

A new generation of fluid pressure forming technology has been developed for the three typical structures of tubes,sheets,and shells,and hard-to-deform material components that are urgently needed for aerospace,aircraft,automobile,and high-speed train industries.in this paper,an over all review is introduced on the state of the art in fundamentals and processes for lower-pressure hydroforming of tubular components,double-sided pressure hydroforming of sheet components,die-less hydroforming of ellipsoidai shells,and dual hardening hot medium forming af hard-to-deform materiais Particular attention is paid to deformation behavior,stress state adjustment,defect prevention,and typical applications.In addition,future development directions of fluid pressure forming technology are discussed,including hyper lower-loading forming for ultra-large non-uniform components,precision for ming for intermetallic compound and high-entropy alloy components,intelligent process and equipment,and precise finite element simulation of inhomogeneous and strong anisotropic thin shells.

Development of pressure control system in counter gravity casting for large thin-walled A357 aluminum alloy components

Counter gravity casting equipments(CGCE) were widely used to produce large thin-walled A357 aluminum alloy components. To improve the pressure control precision of CGCE to get high quality castings, a pressure control system based on fuzzy-PID hybrid control technology and the digital assembled valve was developed. The actual pressure tracking experiment results show that the special system by applying PID controller and fuzzy controller to varied phases, is not only able to inherit the small error and good static stability of classical PID control, but also has fuzzy control’s advantage of fully adapting itself to the object. The pressure control error is less than 0.3 kPa. By using this pressure control system, large complex thin-walled A357 aluminum alloy castings with high quality was successfully produced.

Optimum Heating of Thick-Walled Pressure Components Assuming a Quasi-steady State of Temperature Distribution

As a result of the development of wind farms,the gas- steam blocks,which shall quickly ensure energy supply in case the wind velocity is too low,are introduced to the energy system.To shorten the start-up time of the gas-steam and conventional blocks,the structure of the basic components of the blocks are changed,e.g.by reducing the diameter of the boiler,the thickness of its wall is also reduced.The attempts were also made to revise the currently binding TRD 301 regulations,replacing them by the EN 12952-3 European Standard,to reduce the allowable heating and cooling rates of thick walled boiler components.The basic assumption,on which the boiler regulations allowing to calculate the allowable temperature change rates of pressure components were based,was the quasi- steady state of the temperature field in the simple shaped component,such as a slab,cylindrical or spherical wall.

Expansion of Application Range of Component Restricting Pressure Change Caused by Oil Temperature Change

One of the advantages of an oil-hydraulic system is that the system keeps the value of oil pressure when the pressurized oil is enclosed in a container.However,when the pressurized oil is enclosed in a head or a rod end chamber of an actuator by a check valve or a shut-off valve,the value of the oil pressure deceases gradually by the leakage from the check valve or the shut-off valve.Then,it is necessary to employ non-leakage valve which is expensive or to control the pressure by using a valve or a pump control.In pressure control,energy to compensate pressure is required.From the view point of cost reducing or especially energy saving,it seems to be desirable to develop a component which prevents this pressure drop without energy consumption.Authors had developed a component restricting pressure change caused by oil temperature change.This component has simple mechanism and hardly needs energy.In this study,the possibility of the component to prevent pressure drop due to leakage is investigated experimentally.Consequently,it makes clear that the component is effective to prevent pressure drop by leakage and the enclosed pressure decreases only about 3%in 3 min and about 7%in 60 min when the target enclosed pressure is 3.5 MPa.

Cardiovascular age of aviation personnel: based on the principal component analysis of heart rate and blood pressure variability

Objective: To introduce a method to calculate cardiovascular age, a new, accurate and much simpler index for assessing cardiovascular autonomic regulatory function, based on statistical analysis of heart rate and blood pressure variability (HRV and BPV) and baroreflex sensitivity (BRS) data. Methods: Firstly, HRV and BPV of 89 healthy aviation personnel were analyzed by the conventional autoregressive (AR) spectral analysis and their spontaneous BRS was obtained by the sequence method. Secondly, principal component analysis was conducted over original and derived indices of HRV, BPV and BRS data and the relevant principal components, PCi orig and PCi deri (i=1, 2, 3,...) were obtained. Finally, the equation for calculating cardiovascular age was obtained by multiple regression with the chronological age being assigned as the dependent variable and the principal components significantly related to age as the regressors. Results: The first four principal components of original indices accounted for over 90% of total variance of the indices, so did the first three principal components of derived indices. So, these seven principal components could reflect the information of cardiovascular autonomic regulation which was embodied in the 17 indices of HRV, BPV and BRS exactly with a minimal loss of information. Of the seven principal components, PC2 orig , PC4 orig and PC2 deri were negatively correlated with the chronological age ( P <0 05), whereas the PC3 orig was positively correlated with the chronological age ( P <0 01). The cardiovascular age thus calculated from the regression equation was significantly correlated with the chronological age among the 89 aviation personnel ( r =0.73, P <0 01). Conclusion: The cardiovascular age calculated based on a multi variate analysis of HRV, BPV and BRS could be regarded as a comprehensive indicator reflecting the age dependency of autonomic regulation of cardiovascular system in healthy aviation personnel.

High-efficiency forming processes for complex thin-walled titanium alloys components: state-of-the-art and perspectives

Complex thin-walled titanium alloy components play a key role in the aircraft,aerospace and marine industries,offering the advantages of reduced weight and increased thermal resistance.The geometrical complexity,dimensional accuracy and in-service properties are essential to fulfill the high-performance standards required in new transportation systems,which brings new challenges to titanium alloy forming technologies.Traditional forming processes,such as superplastic forming or hot pressing,cannot meet all demands of modern applications due to their limited properties,low productivity and high cost.This has encouraged industry and research groups to develop novel high-efficiency forming processes.Hot gas pressure forming and hot stamping-quenching technologies have been developed for the manufacture of tubular and panel components,and are believed to be the cut-edge processes guaranteeing dimensional accuracy,microstructure and mechanical properties.This article intends to provide a critical review of high-efficiency titanium alloy forming processes,concentrating on latest investigations of controlling dimensional accuracy,microstructure and properties.The advantages and limitations of individual forming process are comprehensively analyzed,through which,future research trends of high-efficiency forming are identified including trends in process integration,processing window design,full cycle and multi-objective optimization.This review aims to provide a guide for researchers and process designers on the manufacture of thin-walled titanium alloy components whilst achieving high dimensional accuracy and satisfying performance properties with high efficiency and low cost.

Characterization of magnetically impelled arc butt welded T11 tubes for high pressure applications

Magnetically impelled arc butt(MIAB) welding is a pressure welding process used for joining of pipes and tubes with an external magnetic field affecting arc rotation along the tube circumference. In this work, MIAB welding of low alloy steel(T11) tubes were carried out to study the microstructural changes occurring in thermo-mechanically affected zone(TMAZ). To qualify the process for the welding applications where pressure could be up to 300 bar, the MIAB welds are studied with variations of arc current and arc rotation time. It is found that TMAZ shows higher hardness than that in base metal and displays higher weld tensile strength and ductility due to bainitic transformation. The effect of arc current on the weld interface is also detailed and is found to be defect free at higher values of arc currents. The results reveal that MIAB welded samples exhibits good structural property correlation for high pressure applications with an added benefit of enhanced productivity at lower cost.The study will enable the use of MIAB welding for high pressure applications in power and defence sectors.

External Pressure Forming and Buckling Analysis of Tubular Parts with Ribs

与在外部水力的压力下面改变苗条海角比率(到直径的长度的比率) 弄弯并且形成试管的过程与 three-dimensionalfinite 元素方法被分析(女性) 为学习试管形成的外部压力(EPF ) 。没有心轴，为不同试管空白弄弯压力被预言，并且一个碳钢试管的 EPF 被模仿到有六根肋骨的心轴上。从模拟的厚度分发和弄弯的压力被发现与从实验的那些一致。弄弯压力被显示是苗条海角比率的功能。有 EPF 生产的六根肋骨的管状的部分有一致厚度分布，率仅仅是其变瘦的最大值 5.9% 。

Expression of MMP-9 and -13 on the Pressure Side under Orthodontic Loading

Purpose: The purpose of this study was to investigate the expression of MMP-9 and MMP-13 on compression side of tooth movement. Material and Methods: Twenty male Wistar rats were used for this experiment. Maxillary right first molar was moved orthodontically with a constant force of 20 g and on the side of the maxillary left first molar was used as control group. On the 4th, 10th and 17th days after experiment, 5 rats were euthanized, respectively. Histologic process was processed for immunohistochemical staining of MMP-9 and -13. Results: MMP-9 and -13 expressions were upregulated at day 4 after tooth movement. The expression of MMP-9 was not observed at days 7, 10 and 14, while the expression of MMP-13 was greatly increased at days 7 and 10. Conclusion: This study suggests that different characteristics of MMPs expression may contribute to the remodeling process of collagen fibers in the PDL during tooth movement.

Exploration on Temporal-spatial Difference of Cultivated Land Pressure and Influence Factor Analysis: A Case Study of Guangxi

Based on related statistical data during 1980-2014,change rule of Guangxi cultivated land pressure level was studied. Taking each municipal administrative division as evaluation unit,temporal-spatial change trend of cultivated land pressure level was explored by establishing pressure index model of cultivated land,and principal component analysis was used to explore the driving force of cultivated land pressure. Results showed that from 1980 to 2014 in Guangxi,cultivated land pressure was at level one in 12 years,level two in 19 years and level three in 4 years; mean of cultivated land pressure in each city during 2005-2014 was taken as average level of cultivated land pressure in the city,in which cultivated land pressure values of Chongzuo City,Baise City,Laibin City,Liuzhou City,Fangchenggang City,Nanning City,Hechi City and Guigang City were all lower than average level in Guangxi at the same period. Driving factors of cultivated land pressure index mainly contained urbanization rate,Engel coefficient of rural households(ECRH),per capita cultivated land area,total population and rural per capita net income(RPFI).

液压支架立柱防冲吸能构件优化仿真及压溃实验研究

液压支架作为煤炭开采主要支护设备,经常受到冲击地压影响,防冲吸能构件起到保护液压支架作用,为获得更大的初始支反力峰值与吸能量、更小的支反力分散度,对吸能构件参数细化并通过ABAQUS有限元软件进行吸能构件的建模与压溃冲击仿真,获取吸能构件的吸能性能及屈曲变形形态,验证最优尺寸的吸能性能;对比吸能构件平均支反力的预测数据与有限元仿真数据,误差在15%以内,最优尺寸构件的平均支反力模型预测误差为−3.40%,验证吸能构件预测模型所预测数据较为准确;搭建吸能构件压溃实验台,选择5种加载速度,以准静态压溃方式对定制加工的吸能构件进行轴向加载压溃实验,实验结果表明:不同加载速度轴向压溃实验,支反力波动基本一致,最大初始支反力峰值为2253.52 kN,最大支反力标准差为206.23 kN,最小初始支反力峰值为2096.26 kN,最小支反力标准差为189.83 kN,初始支反力峰值的平均值为2149.32 kN,支反力标准差平均值为196.77 kN;不同压溃速度下的轴向压溃实验数据与吸能构件有限元仿真数据对比,初始支反力峰值、支反力标准差的相对误差分别为5.6%、11.07%;对最优尺寸吸能构件通过预测模型法、有限元仿真法、压溃实验法三种方法进行吸能性能分析,预测模型法的平均支反力为1879.7 kN,有限元仿真法的平均支反力为1945.9 kN,压溃实验法平均支反力为1919.8 kN,预测模型误差3.41%,压溃实验误差−1.3%,通过3种方法的数据验证结果,证明了吸能构件分析方法的可靠性和可行性。

渤海某区块浅层气对工程影响的评估

以渤海某区块项目为例,采用保压取样方法获取待评估区域海底土层样品并对所含气体开展组分测定,定性判断浅层气成因。采用静力触探孔压消散试验方法获取地层中超孔隙水压力,定量评估对含浅层气地层承载力的折减效应。结果表明,内浅层气主要组分为甲烷和二氧化碳,气体含量较低。内地层中的浅层气可能属于生物成因气。含浅层气地层的超孔隙水压力相对上覆有效压力比值约3%,承载力折减因数为1.0%~1.1%。所采取的方法能够有效评估浅层气对海上基础设施和生产安全的影响程度,具有推广价值。

井中永置式套管外三分量光纤MEMS地震检波器研究

针对非常规油气井套管外永置式微振动监测,研制了一种基于光纤法布里帕罗(F-P)干涉原理和微机电(MEMS)技术的三分量光纤MEMS地震检波器,将微地震信号转化为F-P腔长的变化,通过超快光谱探测技术和动态白光干涉解调技术实现高速解调。设计并理论仿真了μm/g量级的高灵敏度MEMS加速度芯片,突破大深度双面套刻工艺完成芯片样品制造。采用高集成度小型化结构设计、无胶封装工艺设计和陶瓷微加工工艺实现25 mm微型外径,满足套管外永置式安装要求,提高了高温检测精度。在实验室完成了检波器与标准电学加速度计的性能对比测试,结果表明:检波器可耐受175 MPa高压和180℃高温,灵敏度分别为1.2382,1.2590,1.0862μm/g,工作频带为0~350 Hz,量程为±5 g,线性度误差<0.01%,抗横向串扰能力<5%。研制的检波器耐高温高压、尺寸小巧、灵敏度高、线性度良好,在非常规油气井储层压裂改造和采油气生产过程中,永置式套管外的三分量光纤MEMS地震检波器可以发挥重要的监测作用。

单组分自交联溶剂型丙烯酸酯压敏胶的制备及应用研究

采用了一种自交联功能单体N-羟甲基丙烯酰胺(NMA),通过自由基聚合方式,制备了一种单组分可自交联无苯溶剂型丙烯酸酯压敏胶。系统研究了自交联单体含量对压敏胶剥离力、黏度、持粘性能和转化率的影响,优选出了NMA最佳使用量。研究结果表明:当自交联单体NMA添加质量分数为0.2%时,压敏胶的剥离力、黏度符合要求,耐温性能优异,65℃高温持粘时间增至10 h,单体转化率较高(达95.2%)。将制得的压敏胶涂布于基材,应用于地毯保护膜,30 d后无翘边现象,且所用溶剂无甲苯,具有环保、低毒优势,证明了本产品具有一定的应用前景。

Harmony SE在民用飞机设计中的应用

随着民用飞机技术精细化和产品复杂性的提高,民用飞机设计已从传统的基于文档的系统工程转变为基于模型的系统工程,系统表达也从以文档为中心转变为以模型为中心。为进一步提高民用飞机设计中系统建模的模型质量与正确性,进而缩短设计的开发周期与成本,探究以模型驱动及验证为主导的系统工程方法在民用飞机设计领域的适用性,建立民用飞机设计的系统工程框架,用以支持民用飞机的可靠设计与高效交付。以Harmony SE建模方法为切入点,介绍其工作流程和建模思想;分析民用飞机在系统工程实践中出现的突出问题,说明Harmony SE方法在民用飞机系统工程领域的适用性,建立民用飞机设计的系统工程实践体系;以油箱增压组件为研究对象,应用实践体系开展组件级系统工程实践。结果表明,文中所提出的民用飞机设计系统工程体系和方法能够正确合理地分配设计需求并建立完整的系统模型,有助于提升现阶段民用飞机设计的效率与准确性。

基于多组分定量联合主成分分析正交偏最小二乘法-判别分析及熵权优劣解距离法的抗菌消炎胶囊质量差异性评价

目的建立主成分分析(PCA)、正交偏最小二乘法-判别分析(OPLS-DA)及熵权优劣解距离法(EW-TOPSIS)评价抗菌消炎胶囊的多组分质量差异。方法采用高效液相色谱法(HPLC)同时测定15批抗菌消炎胶囊中獐牙菜苦苷、獐牙菜苷、绿原酸、3,5-二-O-咖啡酰奎宁酸、知母皂苷BⅡ、知母皂苷AⅢ、原百部碱、对叶百部碱、黄芩苷、汉黄芩苷、黄芩素和汉黄芩素的含量,借助PCA、OPLS-DA及EW-TOPSIS模型对15批消炎胶囊样品进行质量差异分析,筛选出导致差异的特征成分,并进行质量排序。结果12种成分在各自范围内呈现良好的线性关系(r>0.999),平均加样回收率(n=9)96.90%~100.23%(RSD<2.0%)。化学计量学筛选出2个主成分,方差贡献率累计达95.172%;OPLS-DA发掘出黄芩苷、绿原酸、知母皂苷BⅡ和对叶百部碱对抗菌消炎胶囊质量有显著影响;EW-TOPSIS分析结果显示Ci值0.0827~0.8495,15批样品质量差异较大。结论所建立的方法可用于抗菌消炎胶囊质量的综合评价。

高压蒸制-焙烤处理对甜荞粉风味物质的影响

为探明高压蒸汽处理(high pressure steam,HPS)、高压蒸汽-高温短时焙烤(high pressure steam-high temperature short-time roasting,HPS-HTSR)处理、高压蒸汽-低温长时焙烤(high-pressure steam-low-temperature long-time roastin,HPS-LTLR)处理对甜荞粉中挥发性风味物质生成的影响,借助固相微萃取(solid-phase microextraction,SPME)技术和GC-MS对荞麦烤制过程中的挥发性成分进行分离、鉴定,采用主成分分析(principal component analysis,PCA)对不同处理过程中的挥发性成分进行分析,通过计算气味活度值(odor activity value,OAV)确定对主体风味贡献较高的成分。结果显示,经高压蒸制及焙烤处理的荞麦粉中共鉴定出50种挥发性成分,其中对HPS处理后的荞麦风味贡献较大的是醛类和萜烯类,对HPS-HTSR处理后的荞麦风味贡献较大的是醛类、萜烯类以及吡嗪类,对HPS-LTLR处理后的荞麦风味贡献较大的是醛类。PCA表明,荞麦经高压蒸制及焙烤处理后的挥发性风味物质3个主成分累计贡献率达到92.69%,计算不同处理方式后的甜荞风味得分,发现HPS处理后的甜荞得分最高,其次是HPS-HTSR处理后的甜荞,得分最低的为HPS-LTLR处理后的甜荞。

总温总压组合式受感器设计

由于一般总温传感器体积大、功能单一,不能适应小型飞行器安装使用,因此设计了一种小型总温总压组合式受感器。其中,对受感器外形结构、屏蔽罩、密封结构等进行设计,并设计一种温度压力一体式敏感组件,采用玻璃烧结工艺解决敏感组件的耐高温、密封、绝缘等关键技术。通过Fluent流体仿真软件对受感器流场进行模拟仿真,分析引压管对受感器内部流场的影响,结合仿真结果对受感器进行优化设计。经风洞试验校准,在Ma=0.3至Ma=0.9范围内,受感器总温恢复系数≥0.970;Ma=0.3(高度H=0)条件下,受感器时间常数小于0.9 s。1 MPa压力条件下进行气密性测试,1 min内压力下降不超过300 Pa;在Ma=0.3至Ma=1.0范围内总压误差优于±0.02,达到较高的技术指标要求。

应用动态血压监测仪及人体成分分析仪观察氨氯地平贝那普利片(Ⅱ)对原发性高血压患者的疗效

目的 评价动态血压监测仪及人体成分分析仪在氨氯地平贝那普利片(Ⅱ)治疗原发性高血压患者疗效中的作用。方法 110例原发性高血压患者,入组前停用既往所有降压药,洗脱期间,饮食方式不变。2周之后接受氨氯地平贝那普利片(Ⅱ)治疗,监测并比较患者治疗前后动态血压参数(白天、夜间、24 h的收缩压和舒张压)、平滑指数、人体成分[骨骼肌质量、脂肪含量、骨骼肌质量指数(SMI)]。结果 治疗后,白天、夜间、24 h的收缩压分别为(132.58±11.22)、(120.23±12.83)、(126.10±8.11)mm Hg(1 mm Hg=0.133 kPa),均低于治疗前的(148.36±10.42)、(133.11±12.91)、(142.26±10.15)mm Hg,舒张压分别为(75.65±11.96)、(68.31±9.10)、(71.40±8.70)mm Hg,均低于治疗前的(85.03±10.98)、(77.85±10.84)、(83.92±9.89)mm Hg,治疗后的平滑指数(2.00±0.23)高于治疗前的(1.21±0.26),差异具有统计学意义(P<0.01)。患者治疗后的骨骼肌质量(35.75±6.84)kg、SMI(8.38±0.51)kg/m2均高于治疗前的(25.15±6.58)kg、(7.95±0.44)kg/m2,脂肪含量(18.83±4.15)kg低于治疗前的(23.12±4.51)kg,差异具有统计学意义(P<0.01)。结论 氨氯地平贝那普利片(Ⅱ)能有效平稳地降低原发性高血压患者的动态血压,且增加骨骼肌质量、降低脂肪含量,优化人体成分,值得临床推广。

响应面法优化超高压处理赤霞珠葡萄及其对挥发性物质的影响

为了研究超高压处理对赤霞珠葡萄果实挥发性物质的影响,该试验利用顶空固相微萃取与GC-MS技术,通过单因素与响应面试验对超高压处理条件进行优化,并在此基础上结合主成分分析与香气轮廓描述对其特征香气进行分析。结果表明,在超高压处理压力为386 MPa、处理时间为24 min、处理温度为33℃时,赤霞珠葡萄挥发性物质的综合评分最高。利用优化后的条件处理赤霞珠葡萄果实,共检测到43种挥发性物质,和对照相比挥发性物质的个数与总浓度显著增加(P<0.05),主成分分析下处理样品与对照样品有明显的区分,香气轮廓描述发现超高压处理可显著提高赤霞珠葡萄的草本香与花果香。该试验结果将为超高压技术在葡萄酒生产中的应用与推广提供一定的数据参考和技术支持。