THEORETICAL ANALYSIS AND EXPERIMENTAL INVESTIGATION OFTHE INFLUENCE OF BEARINGMISALIGNMENT ON STABILI

ＴＨＥＯＲＥＴＩＣＡＬＡＮＡＬＹＳＩＳＡＮＤＥＸＰＥＲＩＭＥＮＴＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＴＨＥＩＮＦＬＵＥＮＣＥＯＦＢＥＡＲＩＮＧＭＩＳＡＬＩＧＮＭＥＮＴＯＮＳＴＡＢＩＬＩＴＹＯＦＲＯＴＯＲ－ＢＥＡＲＩＮＧ　ＳＹＳＴＥＭＨｕａｎｇＷｅｎｚｈ...     

INVESTIGATION ON COMPRESSIBILITY AND BULK MODULUS OF FLUID

ＩＮＶＥＳＴＩＧＡＴＩＯＮＯＮＣＯＭＰＲＥＳＳＩＢＩＬＩＴＹＡＮＤＢＵＬＫＭＯＤＵＬＵＳＯＦＦＬＵＩＤＣａｏＢｉｎｇｇａｎｇＸｉ＇ａｎＪｉａｏｔｏｎｇＵｎｉｖｅｒｓｉｔｙＡｂｓｔｒａｃｔＴｈｅｐｒｏｂｌｅｍｓｉｎｔｈｅｔｒａｄｉｔｉｏｎａｌｄｅｆｉｎ...     

EXPERIMENTAL STUDY ON THE LOAD DECAY AND ITS EFFECT ON LEAK RATE OF O—RING

Experimental studies on load decay and leak rate of 0-rings made of two kinds of silicone rubber are conducted. The results show that the characteristic of load decay is relative to the material and temperature of O-rings; the rate of load decay increases with the rise of temperature; the effects of load decay on leak rate of 0-rings are negligible at room temperature, but they are notable at high temperature, and they are related to the material of O-rings. On the basis of .study on the theory of load decay and analysis to the results of experiments, a theoretical model is developed to describe the load decay characteristic of O-rings, and it matches the experimental data very well. By the study of time-temperature equivalence of load decay, the interconvertting equation of test data of load decay at different temperatures is obtained.     

THEORETICAL ANALYSIS AND EXPERIMENTAL VERIFICATION ON TERNARY-WAVES METHOD TO COMPILE ACCELERATED SPECTRA

The equivalent damage calculation formulae of fatigue crack formation and growth are established. In order tocompile the fatigue crack formation and growth accelerated load spectra, the main wave shapes and load sequence of theactual load spectrum are kept constant, and the carrier waves are cut off. And secondary waves are put together into newsecondary waves to shorten the test time according to the equivalent damage calculation formulae respectively. Then bythe fatigue cumulative damage calculation of the fatigue crack formation and growth accelerated load spectra, the onecorresponding to the bigger damage is determined as the fatigue accelerated test load spectrum. Therefore in the test process, the fatigue accelerated test spectrum may be applied till fatigue failure, the engineering fatigue crack length of full-scale structure need not be inspected, and the fatigue crack formation accelerated load spectrum need not be transferredinto the fatigue crack growth accelerated load spectrum. Finally, it     

EXPERIMENTAL STUDY ON LUBRICATION BEHAVIOR OF DOUBLE ENVELOPING HOUK GLASSWOKM GEARING

ＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＮＬＵＢＲＩＣＡ－ＴＩＯＮＢＥＨＡＶＩＯＲＯＦＤＯＵＢＬＥＥＮＶＥＬＯ－ＰＩＮＧＨＯＵＫＧＬＡＳＳＷＯＫＭＧＥＡＲＩＮＧＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＮＬＵＢＲＩＣＡ－ＴＩＯＮＢＥＨＡＶＩＯＲＯＦＤＯＵＢＬＥ...     

NUMERICAL SIMULATION AND EXPERIMENTAL STUDY OF A KIND OF LOCAL EXHAUST VENTILATION HOOD

A new local exhaust ventilation hood is presented. First, the test system in laboratory roomis established. Secondly a mathematical model is developed in terms of the stokes stream function, andthe governing equation is solved using finite-difference techniques. The injection flow of the exhausthood is treated as a boundary condition of the main flow. Experiments results well agree with thesolution of theoretical prediction. The model can, therefore, be used to design this kind of Aaberg hood.     

THEORY AND EXPERIMENTAL STUDY OF THE SELF-EXCITED OSCILLATION PULSED JET NOZZLE

Comparing with usual continuous jet nozzle, the self-excited oscillation pulsed jet nozzleSEOPJN) can make jet generate a higher peak of pressure and larger scouring volume. And it can makejet increase the effective standoff distance, too. The basic theories of the SEOPJN are introduced.Some experimental results are shown. According to the results, using tricorn bits assembled theSEOPJN to drill oil well, the ROP increases by 8%～77%, and the rates of the footage for tricorn bitincreases by 6.7%～44.0%.     

STUDY ON MACRO AND MICRO MODELING ON SOLIDIFICATION PROCESS OF SHAPED CASTING

Facing the market economy and global challenge the development of manufacturing industry especially casting industry is critical to the national economy. To reform the traditional casting industry by using computer technology is one of the hottest research frontiers studied by many researchers and engineers. Computer simulation of solidification process of shaped casting can assure the quality of casting, optimize the casting technology, shorten the lead time and therefore decrease the developing and manufacturing cost. Recently, numerical simulation of mold-filling and solidification processes of shaped casting and prediction of microstructure and property as well are extensively studied and put into application in many casting plants with many successful simulation cases.     

STUDY ON WEAR AND DESTRUCTION OF HOB IN GEAR HOBBING

The wear and destruction appearances of hobs are researched. The reasons of the wear and destruction of hobare analyzed. And the influence of the change of the bobbing force and the bobbing temperature on the wear and destruction of hob in gear bobbing is also analyzed. In gear bobbing, the main wear mechanisms are adhesion and ploughingwhen cutting the 20CrMnTi gear using W18Cr4V high-speed steel hob.     

STUDY ON EFFECTS OF PHYSICO－AND CHEMICO－PROPERTIES OF MELTING SLAG ON DETACHABILITY OF SSFCE

ＳＴＵＤＹＯＮＥＦＦＥＣＴＳＯＦＰＨＹＳＩＣＯ－ＡＮＤＣＨＥＭＩＣＯ－ＰＲＯＰＥＲＴＩＥＳＯＦＭＥＬＴＩＮＧＳＬＡＧＯＮＤＥＴＡＣＨＡＢＩＬＩＴＹＯＦＳＳＦＣＥＳＴＵＤＹＯＮＥＦＦＥＣＴＳＯＦＰＨＹＳＩＣＯ－ＡＮＤＣＨＥＭＩＣＯ－ＰＲＯＰＥＲＴＩＥＳ...     

FINITE ELEMENT ANALYSIS AND EXPERIMENTAL STUDY OF THE METAL MULTIDIE IRONING PROCESS

ＦＩＮＩＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＡＮＤＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＦＴＨＥＭＥＴＡＬＭＵＬＴＩＤＩＥＩＲＯＮＩＮＧＰＲＯＣＥＳＳＦＩＮＩＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＡＮＤＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＦＴＨＥＭＥＴＡＬＭ...     

APPLICATION OF MAGNETIZATION VISCOUS CHARACTER OF MAGNETIC FLUID IN ELECTRO-HYDRAULIC SERVO AMPLIFIER

ＡＰＰＬＩＣＡＴＩＯＮＯＦＭＡＧＮＥＴＩＺＡＴＩＯＮＶＩＳＣＯＵＳＣＨＡＲＡＣＴＥＲＯＦＭＡＧＮＥＴＩＣＦＬＵＩＤＩＮＥＬＥＣＴＲＯ－ＨＹＤＲＡＵＬＩＣＳＥＲＶＯＡＭＰＬＩＦＩＥＲＡＰＰＬＩＣＡＴＩＯＮＯＦＭＡＧＮＥＴＩＺＡＴＩＯＮＶＩＳＣＯＵＳＣＨ...     

AFFECTION OF ER FLUID ON STIFFNESS OF VIBRATION SYSTEM

On the application of an electric field, the mechanical properties of ER(Electro-rheological) fluid are very complex. The damping force of ER fluid is linear without electric field and is nonlinear when an electric field is applied. By increasing the strength of the electric field, the behavior of ER fluid changes from linear viscous to nonlinear viscoelastic-plastic. External electric fluid changes natural behavior of system with ER fluid besides the mechanical properties of ER fluid. The affect of ER fluid on the stiffness of nonlinear vibration system with ER dampers is analyzed by iterative perturbation method. The results show that the stiffness of structure would be increased with growing of the strength of the electric field.     

STUDY ON INJECTION AND IGNITION CONTROL OF GASOLINE ENGINE BASED ON BP NEURAL NETWORK

According to advantages of neural network and characteristics of operating procedures ofengine, a new strategy is rapresented on the control of fuel injection and ignition timing of gasolineengine based on improved BP network algorithm. The optimum ignition advance angle and fuelinjection pulse band of engine under different speed and load are tested for the samples trainingnetwork, focusing on the study of the design method and procedure of BP neural network in engine     

EXPERIMENTAL STUDY OF NONLINEAR VIBRATION CHARACTERISTICS OF AN ELASTIC LINKAGE

ＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＦＮＯＮＬＩＮＥＡＲＶＩＢＲＡＴＩＯＮＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＡＮＥＬＡＳＴＩＣＬＩＮＫＡＧＥ￥ＷａｎｇＹｕｘｉｎ；ＺｈａｎｇＣｅ；ＬｕＸｉｎｉａｎ（ＴｉａｎｊｉｎＵｎｉｖｅｒｓｉｔｙ）Ａｂｓｔｒａｃｔ：...     

EXPERIMENTAL STUDY ON HIGH-SPEED CENTRIFUGAL PUMPS WITH DIFFERENT IMPELLERS

The experimental study is carried out on high-speed centrifugal pumps with three different impellers. The experimental results and analysis show that high-speed centrifugal pumps with a closed complex impeller can achieve thehighest efficiency and the lowest head coefficient followed by those with half-open impeller and open-impeller, and canobtain much easily stable head-capacity characrastic curve, while those with a half-open complex impeller can't. Thecharacteristic curve with a open impeller is almost constant horizontal line before dropping sharply. The results also showthat the axial clearance between pump casing and impeller can influence greatly on the performance of centrifugal pumps.     

EXPERIMENTAL INVESTIGATIONS OF CAVITATION EFFECTS ON FLOW CHARACTERISTICS OF SMALL ORIFICES AND VALVES IN WATER HYDRAULICS

The flow characteristics and cavitation effects of water passing through small sharp-edged cylindrical orificesand valves of different shapes in water hydraulics are investigated. The test results using orifices with different aspect ratios and different diameters show that the flow coefficients in the case of non-cavitating flow are larger than that of flow inthe case of cavitation occurrence. The flow coefficients of flow with cavitation initially decrease as Reynolds number increases and ultimately tend to be of constant values close to contraction coefficient. Large aspect ratio has an effect ofsuppressing cavitation. The experimental results about disc valves illustrate that the valves with sharp edge at large opening are less affected by cavitation than that at small opening. Throttle with triangle notch has better anti-cavitation abilitythan that with square notch. The flowrate of the throttle with square notch is significantly affected by the flow direction orthe flow passage shape.     

STUDY ON STRIP AND ROLL DEFORMATION COUPLING OF COLD STRIP ROLLING ON 4-H MILL

ＳＴＵＤＹＯＮＳＴＲＩＰＡＮＤＲＯＬＬＤＥＦＯＲＭＡＴＩＯＮＣＯＵＰＬＩＮＧＯＦＣＯＬＤＳＴＲＩＰＲＯＬＬＩＮＧＯＮ４ＨＭＩＬＬ①ＬｉｕＨｏｎｇｍｉｎＨｕＧｕｏｄｏｎｇＹａｎｓｈａｎＵｎｉｖｅｒｓｉｔｙＡｂｓｔｒａｃｔＴｈｅｃｏｌｄｓｔｒｉｐｒｏｌ...     

STUDY ON STRUCTURE AND PROPERTIES OF 18Si MnCu DUAL PHASE STEEL

ＳＴＵＤＹＯＮＳＴＲＵＣＴＵＲＥＡＮＤＰＲＯＰＥＲＴＩＥＳＯＦ１８ＳｉＭｎＣｕＤＵＡＬＰＨＡＳＥＳＴＥＥＬ￥ＹｕＳｈｅｎｊｕｎ；ＧｏｎｇＦａｎｇｙｕｅ；ＬｉＳｈａｎｙｏｕ；ＷａｎｇＣｈｕｎｙａｎ；ＣｈｅｎＹｕｒｕ；ＣｈｅｎＦｕｍｉｎ（ＴｉａｎｊｉｎＵ...     

EXPERIMENTAL AND NUMERICAL RESEARCH ON BULLDOZER WORKING PROCESS

A simulative analysis coupled with experiment on behaviors of a soil bed cut by a model bulldozer blade is carried out using the finite element/distinct element method(FE/DEM) facility built in the ELFEN package. Before simulation,the soil specimens are examined through uniaxial tensile/compression,triaxial compression and direct shear tests to obtain model characteristics and relevant parameters,then soil cutting experiments are carried out via a mini-soil bin system with a soil bed of 60/120 mm in width and 10 mm in depth cut by a 1/9 scale model bulldozer blade moving with the velocity of 10 mm/s. The soil constitutive model includes the tensile elastic model for tensile breakage and the compressive elastoplastic relationship with Mohr-Coulomb criterion. The cutting length in simulation is set as 1/4 of that in the experiment divided into 1 869 triangular elements. The comparison between the simulated results and experimental ones shows that the used model is capable of analyzing soil dynamic behaviors qualitatively,and the predicted fracturing profiles in general conform to the experiment. Hence the feasibility for analyzing soil fracturing behaviors in tillage or other similar processes is validated.