Vibration Suppression Analysis for Supporter with Constrained Layer Damping

By analyzing the correlation between modal calculations and modal experiments of a typical supporter, an effective finite element analysis( FEA)model of the actual aerospace supporter is created. According to the analysis of constrained viscoelastic damping, the strategies of PVC have been worked out, and the correlation between modal calculations and modal experiments of the supporter has also been computed, and then, an experiment has been designed based on the calculation results. The results of experiments verify that the PVC strategy can effectively suppress vibration.

Practice of Project Management Methodology for Commercial Aero engines Based on Integrative Project Architectures

To collect and share information of projects or products and make it consistent and correct so that the quality and costs of projects can be effectively controlled,an integrative project architecture integrating different types of breakdown structures is necessary.In this paper,the international research status on work breakdown structure(WBS)was analyzed,and an integrative project architecture for commercial aero-engines was designed,where product breakdown structure(PBS),WBS,organization breakdown structure(OBS)and cost breakdown structure(CBS)were integrated and built.And the architecture was applied in information systems.A transfer from technological views of complex products through their lifecycles to management views has been realized with this standardized architecture,thus development tasks and costs can be controlled.

China-Venezuela Space Cooperation Benefits and Review

For the last 10 years,the Venezuelan aerospace industry has been constantly growing,and it is to be expected to continue in the same way in the future.China and its space industry,as the main partner for most of the ongoing Venezuelan space projects from their beginning,has been an important player in their development and may continue acting as one of the most important partners not only for the Venezuelan aerospace industry but also for other Latin-American countries' aerospace industries.ABAE(Bolivarian Agency for Space Activities) together with the related Chinese aerospace companies,with the guidance and help of CGWIC,has been constantly improving its cooperation methods,regarding technical work flows as well as management activities,especially for the latest's space projects under development,namely the CIDE(Venezuelan Design,Assembly,Integration and Testing Center) and VRSS-2(Venezuelan Remote Sensing Satellite-2) programs.Provided that there is a deeper and stronger cooperation in the future,partnership and friendship of the different scientists,experts and leaders from the space sectors of both countries,will be improved and strengthened for the development of both nations social welfare.

Orbital Milling Hole of Aerospace Al-Alloy with Big Pitch

To improve the processing efficiency and the quality of orbital milling hole of aerospace Al-alloy, the big-pitch influence on cutting force and hole quality was studied experimentally. First, a program based on horizontal lathe was proposed based on kinematics analysis of orbital milling. Then, the cutting force at different stages and the hole quality with different pitches were measured. Results show that the axial force and radial force increase with the pitch amplification during orbital milling. However, the axial force in the orbital milling hole is about 8—10 times smaller than that in the conventional drilling. The diameter error of milling hole is 48—93 μm, and the surface roughness of milling hole is 1.2—1.7 μm. Finally, an orbital milling device with big pitch was designed.

Experimental Tests of the Operating Conditions of a Micro Gas Turbine Device

The aim of this work is to analyze the performance of a commercial micro gas turbine, focusing on the analysis of the fuel consumption and the outlet compressor and turbine temperature at various rpm, and to evaluate and compare the efficiency of the device. A test bench has been assembled with the available equipment in the laboratory of the department of mechanical and aerospace engineering in Roma. By using the software supplied by the manufacturer, the evaluation of the operating performance of the device at different speeds has been performed, obtaining all the values of interest.

Value Creation for the After-Sales Services： Organizational and Strategic Perspectives

As a part of the product development process, the after-sales services are not only a source of innovation, but also they benefit from value creation through new managerial methodologies for the achievement of competitive advantage and customer satisfaction. The objective of the paper is to further understand value creation for the after-sales services. We present the case of the creation of a new business for the after-sales services for the entrance into a new market. The new business is created by two gurus in the aerospace industry. A typology of guidelines is derived, based on organizational and strategic perspectives, for the after-sales services value creation and the guidelines for the creation of a new business as well as for the entrance of into a new market are presented.

Could the 2012 Drought in Central US Have Been Anticipated？-A Review of NASA Working Group Research

This paper summarizes research related to the 2012 record the NEWS （NASA （National Aeronautics and Space Administration） drought in the central United States conducted by members of Energy and Water cycle Study） Working Group. Past drought patterns were analyzed for signal coherency with latest drought and the contribution of long-term trends in the Great Plains low-level jet, an important regional circulation feature of the spring rainy season in the Great Plains. Long-term changes in the seasonal transition from rainy spring into dry summer were also examined. Potential external forcing from radiative processes, soil-air interactions, and ocean teleconnections were assessed as contributors to the intensity of the drought. The atmospheric Rossby wave activity was found to be a potential source of predictability for the onset of drought. A probabilistic model was introduced and evaluated for its performance in predicting drought recovery in the Great Plains.

Breeding of an F_1 Hybrid Cultivar Hangjiao Huangshuai by Space Mutation Breeding Technique

Hangjiao Huangshuai is a processing type yellow pepper F1 hybrid cultivar bred with the inbred line 032-1-2-1-1-H-H bred through space treatment as the female parent and 082-1-1-H-H free of space treatment as the male parent. The fruit is in the shape of long finger with few wrinkles and good gloss, and tastes very spicy .The fruit has a vertical diameter of 17.5 cm, a transverse diameter of 1.6 cm, a fresh thickness of 0,20 cm and a single fruit weight of 15.6 g. It is yellowishgreen in the early maturation stage and yellow in the late maturation stage. The cultivar exhibited high resistance to pepper blight, viral diseases and powdery mildew, and showed an average yield of 56 493,0 kg/hm^2. It could be generalized in Gansu, Ningxia, Liaoning and Zhejiang.

Evaluation of accelerated deterioration in NAPTF flexible test pavements

Previous research studies have successfully demonstrated the use of artificial neural network (ANN) models for predicting critical structural responses and layer moduli of highway flexible pavements. The primary objective of this study was to develop an ANN-based approach for backcalculation of pavement moduli based on heavy weight deflectometer (HWD) test data, especially in the analysis of airport flexible pavements subjected to new generation aircraft (NGA). Two medium-strength sub-grade flexible test sections, at the National Airport Pavement Test Facility (NAPTF), were modeled using a finite element (FE) based pavement analysis program, which can consider the non-linear stress-dependent behavior of pavement geomaterials. A multi-layer, feed-forward network which uses an error-backpropagation algorithm was trained to approximate the HWD back-calculation function using the FE program generated synthetic database. At the NAPTF, test sections were subjected to Boeing 777 (B777) trafficking on one lane and Boeing 747 (B747) trafficking on the other lane using a test machine. To monitor the effect of traffic and climatic variations on pavement structural responses, HWD tests were conducted on the trafficked lanes and on the untrafficked centerline of test sections as trafficking progressed. The trained ANN models were successfully applied on the actual HWD test data acquired at the NAPTF to predict the asphalt concrete moduli and non-linear subgrade moduli of the me-dium-strength subgrade flexible test sections.

Structural Aerospace Composite/Metallic Samples under Fatigue Loads： Experimental Activity on Three Case Studies

The use of composite materials in aerospace engineering is ever increasing. Properties such as low weight, high performance, high stiffness and the ability for it to be tailored specifically for different structural uses has increased its importance in recent years. Specific experimental/numerical activities were developed in the last decade at the aerospace department of Polito and are under consideration in recent years regarding the analysis of fatigue behavior of composite/metallic structural samples under cyclic loading condition. A review of the main significant results connected to three case-studies is presented in the paper. The first is related to the definition and analysis of innovative joint for composite high aspect ratio aircraft structures. The modular design oriented to limit component dimensions for transportability requires the presence of a removable joints able to overcome the typical low bearing failure level of composite pin-loaded joint under static and fatigue loading distribution according to airworthiness requirements. The static experiments demonstrate the consistency of the proposed advanced joint configuration that postpones the joint failure to high load level according to the structural requirements. The cyclic loading phase takes as reference point the failure load of the initial configuration and defines a loading cycle with a maximum higher than the failure load of the initial configuration. The fatigue behavior of the advanced joint also demonstrates a substantial consistency with expected duration of 1 e6 cycles as required by the structural design for operating reasons. Specific indication on fatigue limit with respect to critical amplitude is reported. The second is related to the presence of specific damaged situation in thin-walled fiat/stiffened composite plate. Stiffened configurations are frequently used to increase buckling load level. Unexpected events on solid/stiffened composite panels can introduce a certain level of damage, typically delamination, that can cause reduction in buckling design level and reduction in global strength. The presence of cyclic load and fatigue effect can have an important consequence on damage propagation and structural integrity. The damaged area determined by the skin-stiffener de-bonding of a certain dimension is investigated under static compression and cyclic compression. Local buckling of damaged area is determined and pointed out by tests in uniaxial compression. The experimental static behavior points out the presence of a snap-effect during loading and un-loading. Fatigue loading configuration is applied in the range of post-critical local configuration considered as the most effective situation. Preliminary fatigue results are presented and discussed. The third is related to preliminary investigation on the effect of fatigue life reduction of 2024 AI alloy in corrosive （exfoliation） environment. The effect of corrosion is taken into consideration introducing specific concentration factors into the life estimation relationship. Differences between fatigue in prior corroded specimens and fatigue in presence of corrosive environment are emphasized. No crack propagation is considered. Related concentration factors are derived and compared by the few experimental results in order to define some guidelines for design process and to improve aircraft better evaluation of component structural integrity in operative situations. A preliminary approach is presented in the paper in order to correctly identify the contribution of corrosive environment in coupled fatigue loading phase. The results are discussed and future improvements are suggested.

China Launches Communications Satellite Alcomsat-1 for Algeria

China launched Algeria’s communications satellite,Alcomsat-1,on a LM-3B carrier rocket into its preset orbit from the Xichang Satellite Launch Center at 00：40 Beijing time on December 11 successfully.Alcomsat-1 is Algeria’s first communications satellite as well as the first cooperative project in the aerospace industry between China and Algeria.

Construction of QIAN Xuesen's Meta-Synthetic Wisdom System and Aerospace Hall for Workshop for Meta-Synthetic Engineering

China's aerospace industry is facing a major task of increasing the reform of aerospace management system and speeding up civil-military integration, which leads to an urgent demand for new aerospace think tank products. Thankfully, with "information space" as the carrier, the "systems science" as the guidance, and QIAN Xuesen's "metasynthetic wisdom system" as the core, QIAN Xuesen think tank provides the decision support for China to develop an aerospace knowledge economy and to continuously enhance the "space soft power". In this paper, the framework of the meta-synthetic wisdom system guided by systems science is presented, the relationship between basic ideas of QIAN Xuesen think tank and meta-synthetic wisdom system is explained and the construction items of aerospace hall of the workshop for meta-synthetic engineering(aerospace HWMSE) are analyzed.

Promotion and Application Prospects of Disruptive Technology in Future Development of Space Industry

Space is a high-tech field integrating materials, electronic information, manufacture, energy, medicine ana other disciplines. A number of disruptive technologies in various fields will have an important influence in areas such as space industry, scientific research on space and even military space. This article focuses on disruptive technologies exerting enormous influence in the space field based on the qualitative and quantitative research of disruptive technolo- gies. The research and application for disruptive space technology is expected to greatly improve the emciency of space system, significantly reducing research cost, and to promote a great improvement of space technology level,

2012年国际航空钛市场需求高涨

目前,金融危机引发一场世界性的经济危机。2008年下半年全球经济市场明显放缓,下行风险越来越大。在商业航空领域,波音与空客两家公司的飞机订单大幅度减少,2009年一季度仍在下滑。然而,据预测这场危机的影响仅是中短期的;从长远来看,各国航空业及其它用钛量仍然看好。世界航空钛市场主要集中在美国、俄罗斯、欧洲等国家和地区。据美国地质勘探局(USGS)数据显示,2010年国内轧材装运量涨幅达38.3%,至8,440万磅,2011年末可达8,950万磅新高,甚至可能超过9,000万磅。

2008中国制造业十大新闻

■金融风暴波及制造业去年下半年,中国制造业已有些许寒意。国外出口订单出现萎缩,国内受人民币升值、原材料价格上涨、出口退税不断降低等因素的影响,出口价格优势也逐渐减弱,部分中小企业倒闭。2008年,美国次贷危机上升为全球性金融风暴,并大规模影响实体经济,中国制造业开始过冬。为扩内需、保出口、促增长。

A survey of numerical algorithms for trajectory optimization of flight vehicles

As one of the important components of computational flight mechanics and control,numerical algorithms of trajectory optimization for flight vehicles are currently studied by many researchers in aerospace engineering to completely solve these difficult problems,but few papers on the survey of this research field have been published recently.Based on the investigation of more than one hundred literatures,considering the application perspectives of computational flight mechanics and recent developments of trajectory optimization,the numerical algorithms of trajectory optimizations for aerospace vehicles are summarized and systematically analyzed.This paper summarized the basic principle,characteristics and application for all kinds of current trajectory optimization algorithms;and introduced some new methods and theories appearing in recent years.Finally,collaborative trajectory optimization for many flight vehicles,and hypersonic vehicle trajectory optimization were mainly reviewed in this paper.In the conclusion of this paper,the future research properties are presented regarding to numerical algorithms of trajectory optimization and control for flight vehicles as follows:collaboration and antagonization for many flight vehicles and multiple targets,global,real-time online,high accuracy of 7-D trajectory,considering all kinds of unknown random disturbances in trajectory optimization,and so on.

A perspective on high-order methods in computational fluid dynamics

There has been an intensive international effort to develop high-order Computational Fluid Dynamics(CFD) methods into design tools in aerospace engineering during the last one and half decades. These methods offer the potential to significantly improve solution accuracy and efficiency for vortex dominated turbulent flows. Enough progresses have been made in algorithm development, mesh generation and parallel computing that these methods are on the verge of being applied in a production design environment. Since many review papers have been written on the subject, I decide to offer a personal perspective on the state-of-the-art in high-order CFD methods and the challenges that must be overcome.

Problems of the conventional BL model as applied to super/hypersonic turbulent boundary layers and its improvements

Turbulence modeling has played important roles in solving engineering problems. However, with the development of aero-space technology, turbulence modeling faces new challenges. How to further improve turbulence modeling for su-per/hypersonic flows is an urgent problem. Through analyzing a set of data resulting from DNS and experiments, it is foundthat some most popular models suffer from essential flaws, and can be hardly improved following the traditional mode ofthinking. On the contrary, the BL model, which is one of the simplest and widely-used models, can be further improved. In thispaper, through analyzing results from DNS data, the main cause of the inaccuracy in applying the BL model to supersonic andhypersonic turbulent boundary layers is found to have resulted from the mismatch between the location of the matching pointof the inner and outer layers of the BL model determined by the conventional way and those given by DNS. Improvement onthis point, as well as other improvements is proposed. Its effectiveness is verified through the comparison with DNS results.

Application of piezoelectric fiber composite actuator to aircraft wing for aerodynamic performance improvement

The application of actuator made of piezoelectric material,particularly the advanced piezoelectric fiber composite due to the rapid development of smart materials and structures and active control technology in aviation and aerospace industry,to aircraft for performance enhancements such as flight control,aerodynamic force optimization,structure weight reduction,and overall aircraft design represents a new challenge to researches.It is considered as one of the key technologies for developing future flight vehicle.An approach with virtual control surface instead of conventional control surface to control aerodynamic force distribution and flight performance by use of piezoelectric fiber composite actuators distributed on wing surface is presented here.Particularly,the design and implementation of increasing lift force,providing roll maneuver,decreasing induced drag and wing root moment in different flight environments by the same structure control platform are studied.The control effect and sensitivity are examined quantitatively.Generally speaking,better control effect can be obtained by making better use of aeroelastic character to enlarge the actuation strain produced by piezoelectric material.

A Survey of Repetitive Control for Nonlinear Systems

In aerospace engineering and industry, control tasks are often of a periodic nature,while repetitive control is especially suitable for tracking and rejection of periodic exogenous signals.Because of limited research effort on nonlinear systems, we give a survey of repetitive control for nonlinear systems in this paper.First,a brief introduction of repetitive control is presented.Then,after giving a brief overview of repetitive control for linear systems,this paper summarizes design methods and existing problems of repetitive control for nonlinear systems in detail.Lastly,relationships between repetitive control and other control schemes are analyzed to recognize repetitive control from different aspects more insightfully.