MODAL ANALYSIS OF A LIGHTWEIGHT STRUCTURE—INVESTIGATION OF THE EFFECTS OF THE SUPPORTS ON THE STRUCTURAL DYNAMICS

This study grew out of the use of vibration to modify welding stresses, and the corresponding need to understand the modal vibration properties of the test structures. Supporting the structure is a practical problem in experimental modal analysis. In this study the effect of the supports on the dynamic properties of a lightweight structure were investigated. Thick rubber bungee supports and thin elastic band supports were used in the investigation. The effect of the position of the supports was found to be insignificant if a proper type of support is used. It was observed that with the thick bungees the modes become invisible or obscure on the frequency response function (FRF) curves. On the other hand, the thin elastic band supports provide very clear FRF curves and hence clear mode shapes. It has been suggested that the bungees should be chosen considering the weight of the structure and the requirement of the vibration amplitude in the modal analysis and/or in the subsequent treatments. The position of the bungees should be chosen at the node points of a particular mode of the structure to reduce the support effects further.     

FROM THE FIRST THREE MINUTES OF THE UNIVERSE TO THE AIR POLLUTION IN CHINA——35 YEARS IN THE LIFE OF A MASS SPECTROMETRIST

ThispaperwillreportaboutvariousapplicationmeetduringourscientificcareerItwillbeextractfromabout20of60paperswehaveproduced.wewilljustlistThetitleofThesepublicationstogiveatasteofWhatwillbePresented.MassSpectrometricMeasurementofLithium,Beryllium,andBoronIsotopesProducedin16byHigh-EnelgyProtons,andSomeAstrophysicalimplications(1968).StUdyofSecondaryionEmissionofcopperandsomeoftheiralloysbyprimaryionbombardementbyCs (1977).MassSpectrometryappliedtoArtificialLUngDesignandEvaluation(1976…     

NOVEL METHOD OF REALIZING THE OPTIMAL TRANSMISSION OF THE CRANK-AND-ROCKERMECHANISM DESIGN

A novel method of realizing the optimal transmission of the crank-and-rocker mechanism is presented. The optimal combination design is made by finding the related optimal transmission parameters. The diagram of the optimal transmission is drawn. In the diagram, the relation among minimum transmission angle, the coefficient of travel speed variation, the oscillating angle of the rocker and the length of the bars is shown, concisely, conveniently and directly. The method possesses the main characteristic. That it is to achieve the optimal transmission parameters under the transmission angle by directly choosing in the diagram, according to the given requirements. The characteristics of the mechanical transmission can be improved to gain the optimal transmission effect by the method. Especially, the method is simple and convenient in practical use.     

STUDY ON THE FEEDFORWARD COMPENSATION OF THE MOTIONERRORS OF NC MACHINE TOOLS

ＳＴＵＤＹＯＮＴＨＥＦＥＥＤＦＯＲＷＡＲＤＣＯＭＰＥＮＳＡＴＩＯＮＯＦＴＨＥＭＯＴＩＯＮＥＲＲＯＲＳＯＦＮＣＭＡＣＨＩＮＥＴＯＯＬＳＹｕＷｅｎｈｕａ；ＷｕＺｈａｏｔｏｎｇ（ＺｈｅｊｉａｎｇＵｎｉｖｅｒｓｉｔｙ）ＡｂｓｔｒａｃｔＡｆｅｅｄｆｏｒｗａｒｄ...     

DEVELOPMENT OF THE CONTROL METHODOLOGY OF THE GIANT MAGNETOSTRICTIVE ACTUATOR BASED ON MAGNETIC FLUX DENSITY

According to the principle of the magnetostriction generating mechanism, the control modelof giant magnetostriction material based on magnetic field and the control method with magnetic fluxdensity are developed. Furthermore, this control method is used to develop a giant magnetostrictivemicro-displacement actuator (GMA) and its driving system. Two control methods whose control vari-ables are current intensity and magnetic flux density are compared with each other by experimentalstudies. Finally, effective methods on improving the linearity and control precision of mi-cro-displacement actuator and reducing the hysteresis based on the controlling magnetic flux densityare obtained.     

MASS SPECTROMETRLC STUDY OF THE CHEMLCALKINETICS OF THE CH_2CIO OXY RADLCAL REACTIONS

TheCH2CIOradicalisanintermediateinTheatmosphericoxidationofCH,CI.AlthoughCH,CIoccursnaturallyinTheatmosphereandisnotareplacementspecies,wehaveundertakenTheCH2CIOworktogainbetterunderstandingofTheatmosphericchemistryofCH3CI.ThekineticsofThechloromethoxyradicalreactionswasinvestigatedat235Torrand265-348KbyUVflashphotolysisofCH3CI-O2-NOCI-NOgasmixturesandtimeresolvedmassspectrometry.Quadrupolemassspectrometerwithlowelectronionizationenergy(15-30ev)iscoupledwithatemperaturecontrol…     

THE INFLUENCE OF PERIOD VARIATION ON TIME–FREQUENCY ANALYSIS OF THE WESTLAND HELICOPTER DATA

In this work, we address the influence of period variation on the Westland CH-46E helicopter vibration data. The estimation of the time-varying shaft speed by using a newly developed constrained AR(2) estimator and the well-known EKF estimator will be discussed. The influence that the period variation captured by these two estimators have on the periodic time–frequency analysis will be illustrated via numerical simulation. This simulation clearly illustrates a potential spectral smearing if the period variation is not properly accommodated. A data resampling scheme will then be proposed to eliminate the spectral smearing effect. The potential of this scheme will be demonstrated via the analysis of the helicopter vibration data.     

NEW TECHNOLOGY AND MACHINE TOOL FOR THE FORMING OF THE REAR AXLE SHAFT OF LIGHT TRUCK

A new technology of forward extrusion and cross rolling has been developed to process the rear axle shaft sleeve of light truck with the use of tube billets. This technology is characterized by large reductions of material, energy and cost of production and has significant economical benefits. This technology is stable and reliable. The three rolls transverse rolling mill built based on this technology has novelty construction, higher production efficiency, non-vibration and noise. The research results have been extensively applied to light trucks and farm transport with load of 1 to 3 tones.     

CALCULATIONS OF THE INNER DISTURBANCE FREQUENCIES INSIDE THE EPICYCLIC GEARING

ＣＡＬＣＵＬＡＴＩＯＮＳＯＦＴＨＥＩＮＮＥＲＤＩＳＴＵＲＢＡＮＣＥＦＲＥＱＵＥＮＣＩＥＳＩＮＳＩＤＥＴＨＥＥＰＩＣＹＣＬＩＣＧＥＡＲＩＮＧＣＡＬＣＵＬＡＴＩＯＮＳＯＦＴＨＥＩＮＮＥＲＤＩＳＴＵＲＢＡＮＣＥＦＲＥＱＵＥＮＣＩＥＳＩＮＳＩＤＥＴＨＥＥＰＩ...     

NUMERICAL MODELLING OF THE ROLL FORMING PROCESS OF CHANNEL STEEL

０ＩＮＴＲＯＤＵＣＴＩＯＮＣｈａｎｎｅｌｓｔｅｅｌｉｓｗｉｄｅｌｙｕｓｅｄｉｎｃｉｖｉｌｅｎｇｉｎｅｅｒｉｎｇ，ａｎｄｔｈｅｒｏｌｐａｓｄｅｓｉｇｎｉｓｖｅｒｙｉｍｐｏｒｔａｎｔｉｎｉｔｓｐｒｏｄｕｃｔｉｏｎ．Ｉｆｙｏｕｗａｎｔｔｏｍａｋｅｒｅａｓｏ...     

PHYSICAL MODEL FOR THE ENGINEERING ANALYSISOF THE THERMOELASTICLTY OF SOLID BODIES

Latin lettersa--V~ diedon in the mol~ d~ cellb~Vector diedon in the ~ dboc Cellc~VeCtor inchon in the moleculax ~ cellc~Speilic heat capeity(J' kg~ l' K~' )D--Finite sabin tensorE--Sthen tenSOrG~Metric ten8Orh--hanetrical ~e ie~ in themolectilar dMc cellL~an(J)m--Mass(kg) N~ n~ Of Particlesp~Hy~c mpsme(Pa)q--toe heat now rate (w.m-= )--POSihon(m)S--Vector ghhon in the molecthedwtc referee(m)S--Sness tensor(N' m-' )t~(s)T~(K)u--Vector displacement(m)~boas pennal(J)~Arbitw constant…     

STUDY ON THE INFLUENCES OF BUBBLY OIL ON THE CAVITATION EROSION IN JOURNAL BEARINGS OF ENGINES

0 INTRODUCTIONWhen water, minera1 oil or any other kind offluid flow over a element surface, such as propeller,pump, valve, pipe, bearing, gears, injector, etc, becauseof a change of flow rate or a change of localgeometrical figuration, the local pressure will decreaserapid1y. If the local pressure becomes lower than thesaturation pre8sure of this kind of fluid, the dissolvedgases will come out of solution as bubbles. Besides, ifthe local pressure is below the vaPOr pressure of thisfluid,…     

APPLICATIONS OF MEMBRANE EXTRACTION-MICROTRAP IN THE ANALYSIS OF ORGANIC MASS SPECTROMETRY

Theconcentrationofvolatileorganiccompounds(VOCs)inThesamplesisusuallyunderppblevel,andthesesamplesusuallycontainalargeamountofwater.ThismakesTheirdirectdeterminationdifficult.Typicalsamplepreparationmethodssuchalliquid-liquidextraction,steamdistillation,directhead-space,andpurge/trapmethodsforcollectingvolatileshavevariousdrawbacks.includingheavyandcomplicatedapparatus,costandexcessivepreparationtime.Onthebasisofourrecentworkswedesignedandmadeamembraneextractionmodule(ME)andaMicroTrap(MT)u…     

ANALYSIS OF THE DEFLECTION OF REEDS IN AUTOMOTIVE HYDRAULIC SHOCK ABSORBERS

0 INTRODUCTIONAn automotive by~ic shock absolver is an import unit of suspension, can damp the vibndion Offare and lady qUickly, and improves ride and handling c~teristics. Many shock absorbers use reedsas extension and compression valve, because they can s~ify the structure of shock absorbers. To get thereopired rebound and compression resistance, the different thick reeds ~ overlaPPed together. In older tOfomeast foe oh~teristics of the shock absorber, many rese~hers are striating for…     

STRUCTURAL ANALYSIS OF THE REFLECTING SURFACE SYSTEM OF A LARGE ASTRONOMICAL TELESCOPE

The reflecting Schmidt plate system of the large sky area multi-object fiber spectroscopic telescope (LAMOST) serves active optical correction with a reflecting surface of segmented mirror. An azimuth-altitude mounting is adopted with two self-aligning ball bearings for altitude axis and hydrostatic bearings for azimuth. With static and modal analyses, finite element modeling of the full Schmidt plate system is discussed. Conventional seismic response spectrum has been adapted for particular application for telescope engineering before a seismic response spectrum analysis is performed, and results have confirmed that the design of the reflecting Schmidt plate manifests good performance and can survive the seismic intensity of up to 7 magnitude specified by technical requirements.     

RONDA SWITZERLAND──THE POWER OF PARTNERSHIP

Whereas most people are famil-iar with many watch brands, espe-cially those that have a prestigiousring to them, the manufacturers ofwatch movements work mainly be-hind the scenes. One of the biggestproducers of quartz movements isRONDA AG, based in Lausen,SwitZerland.Founded in 1946 by WilliamMosset, RONDA has grown into adynamic player in Switzerland'swatchmaking industry. The groupemploys some 1800 peopleworldwide. In addition to the headoffice, it has production sites in south-ern …     

ANALYSIS SOLUTION OF BULGING CONVEXITY OF THE HYDRAULIC ELASTIC BULGING ROLL

ＡＮＡＬＹＳＩＳＳＯＬＵＴＩＯＮＯＦＢＵＬＧＩＮＧＣＯＮＶＥＸＩＴＹＯＦＴＨＥＨＹＤＲＡＵＬＩＣＥＬＡＳＴＩＣＢＵＬＧＩＮＧＲＯＬＬＡＮＡＬＹＳＩＳＳＯＬＵＴＩＯＮＯＦＢＵＬＧＩＮＧＣＯＮＶＥＸＩＴＹＯＦＴＨＥＨＹＤＲＡＵＬＩＣＥＬＡＳＴＩＣＢＵＬＧ...     

EXPERIMENTAL STUDY OF EFFECTS OF OPERATING CONDITIONS ON THE FLOW CHARACTERISTICS OF WATER HYDRAULIC THROTTLE

Experimental investigations are made on the effects of operating conditions on the flow characteristics of throttle when tap water is used as the working media. The researched throttles include cone poppet valve, ball valve, disc valve and dumping orifice. Operating condition includes poppet lift, working media, back pressure, medium temperature, etc. Because the vapourous pressure of water is much higher than that of oil, cavitation is easier to occur in water hydraulic elements and systems, so the effects of operating conditions on the cavitation characteristics of throttle are also researched.     

THE EFFECT OF THE CUTTING FLUID ON SURFACE ROUGHNESS IN BORING OF LOW CARBON STEEL–TECHNICAL COMMUNICATION

In spite of their environmental and human health problems, the cutting fluids still have been used widely in industry due to cutting fluid application can increase cutting performance in metal cutting. In this article, the effect of the cutting fluid on surface roughness in boring of AISI 1030 low carbon steel was investigated depending on BUE and chip formations and other cutting parameters, such as cutting speed, feed rate and tool nose radius. In most of boring experiments, the wet cutting did not show more preferable results than dry cutting. However, cutting fluid application with big nose radius and small feed rate improved the surface roughness up to 80%. This progress was attributed to a favorable chip formation as much as effective cooling.