1996 Vol.9(3)

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STUDY ON ISOMORPHISM OF PLANAR KINEMATIC CHAINS
1996, 10(3).
[Abstract](2259) [PDF 204KB](83)
Abstract:
The isomorphism of planar kinematic chains is studided. The original methods for detecting isomorphism is discussed. A new matrix, the link-link path matrix, is presented to show the structures of planar kinematic chains. It is simple and reliabel to detect isomorphism of planar kinematic chains by using the link-link path matrix.
STUDY ON WAKING BOAT-TYPE TRACTOR
1996, 10(3).
[Abstract](2142) [PDF 296KB](73)
Abstract:
In order to raise the tractive efficiency of a boat-type tractor further, according to a point of view about reducing energy consumption by reducing the volume of the balde cavity, and idea of four-footed walking boat-type tractor is put forward, and a walking device with two feet and four small wheels is designed and manufactured. It can move on the rails of a paddy soil bin to simulate the tractive performance of a boat-type tractor in the paddy field. Kinematics and dynamics of the walking device is analysed. Because it can ensure that the blade foot enters and leaves the soil vertically, and eliminates the functions of the soil compression and pick by the blade entirely, so the volume of the blade cavity can be reduced to a minimum and the efficiency of the walking system has been rasied considerably. Thus, it is feasible to adopt a four-footed walking mechanism in the boat-type tractor.
STUDY ON AUTOMATIC BALANCE TECHNOLOGY FOR THE RIGID ROTOR
1996, 10(3).
[Abstract](2082) [PDF 222KB](95)
Abstract:
The theory and application of automatic balance technology for the rigid rotor is researched. New analysis about the mechanical model of vibratory system is done in view of feature of automatic balance, and the result is that the accurate model of system can be gained by compensation method and the traditional principle error of balance machines both for soft and hard bearing can be overcome. The automatic balance testing theory for soft and hard bearing can be overcome. The automatic balance testing theory for soft and hard bearing machines is proposed. The automatic balance system has been developed and the function and technical key is also introuduced in detail.
INVESTIGATION ON BRITTLE FRACTUREPROPAGATION-ARRESTING CHARACTERISTICS OF STEEL PIPE
1996, 10(3).
[Abstract](2067) [PDF 182KB](92)
Abstract:
In order to study crack propagation-arresting characteristics of steel pipe construction, a new test installation was designed. The experiments of 20 steel pipes, pipes with longitudinally weld, pipes with circumferential weld and steel pipe with sleeve were conducted. The testing results indicated that circumferential weld in pipe with overmatching weld had beneficial feeect on crack propagation arresting properties and the mechanical split sleeve can be used as crack arrrester to prevent cranck propagation.
STUDY ON THE MECHANISM TO IMPROVE PERFORMANCE OF CARBIDE BLADE BY LASER
1996, 10(3).
[Abstract](2067) [PDF 343KB](136)
Abstract:
The expermental rescarch on the change of chemical composition and structure of carbide blade surface treated by laser is carried out, and the relation between their structure and performance is studied. The result shows that the element Coexists as a simple substance phase in primitive sintering structure, while in new melt-sintering structure it forms a fine alloy phase with original carbide, and this is the main factor which improves the performance of carbide blade treated by laser.
TOOTH PROFILE ANALYSIS AND BASIC PARAMETER DETERMINATION OF PUSH-ROD REDUCTOR
1996, 10(3).
[Abstract](2092) [PDF 148KB](69)
Abstract:
By means of the relationship between working angle of inside and outside roller, a new method of analyzing tooth profile and its property of push-rod reductor is presented. The principle of determining basic design parameters of the push -rod reductor based on the contact stress is studied. These make the basis for analysis and optimum design of the push-for reductor.
EXPERIMENTAL STUDY ON ELASTIC-PLASTIC CONTROLLING DESIGN FOR BOX STEEL STRUCTURES
1996, 10(3).
[Abstract](2104) [PDF 148KB](91)
Abstract:
The priciple of increasing structural loading abillity by the using of elastic-platic controlling design, which can make steel reach a higher yield strength through controlling undue strains produced in loaded box steel structures and no damager to the static mechanical propertise of the used materials, is dealt with under the guarantee of strength, rigidity, and stability. A new idea of elastic-plastic controlling design, which is mainly based on the elastic-plastic theory and experimental results and is different from the current design which is mainly based handbooks and designer's experiece, is established. That is: the loading time and its effect on loaded structures are considered, and the potential strength in used materials is fully utilized through the controlling of structural strains in design. By the using of this design method, the weight and cost of box structures will be reduced in large amount.
MODELING OF A SOLID CONE PRESSURE-SWIRL ATOMIZER
1996, 10(3).
[Abstract](2170) [PDF 273KB](212)
Abstract:
A Balistic Modeling (BM) / Discrete Droplet Modeling (DDM) method is used to determine the characteristics of a solid cone pressure-swirl atomizer (Dyna Coin nozzle). The characteristic of its liquid spray is of considerable importance to the operation and performance of combustion systems. A two-dimensional spray model has been developed to simulate a continuous spray under steady-state condition. This model can simulate the resultant drop-size of atomization and reveal the effects of the important physical variables such as fuel injection pressure, air pressure (or density), co-axial air flow and fuel properties on the result of atomization process. Dimensional analysis is used to simulate the drop-size immediately after jet breakup and further breakup of the droplets is determined by testifying the critical condition of aerodynamics breakup I.e.(Wed)c=8/CD.
ACQUIREMENT AND COMPUTER PROCESSING OF 3-D SURFACE SHAPE DATA
1996, 10(3).
[Abstract](2130) [PDF 255KB](110)
Abstract:
The laser scanning and CCD image-transmitting measurement method and principle on acquiring 3-D curved surface shape data are discussed. Computer processing technique of 3-D curved surface shape (be called "3-D surface shape" for short) data is analysed. This technique includes these concrete methods and principles such as data smoothing, fitting, reconstructing, eliminating and so on. The example and result about computer processing of 3-D surface shape data are given.
POWER FLOW ANALYSIS FOR A NEW ISOLATION SYSTEM-FLEXIBLE FLOATING RAFT
1996, 10(3).
[Abstract](2124) [PDF 169KB](126)
Abstract:
A new model for a raft isolation system is proposed, in which the raft supports two machines on a flexible foundation via a series of isolators. The interaction between the flexible floating raft and the non-rigid foundation is studied by the novel approach of power flow. The power flow input and transmited in the complicated compound system are then formulated in closed forms, in which the coupling between the raft and the foundation is considered. The effect of the raft flexibility on power flow spectra is also revealed. This study shows that it may lead to an overoptimistic evaluation to the effectiveness of the raft isolation when simplifying the raft to an ideal rigid structure. Thereby, the reliable estimation and effective design for raft isolation system are provided.
STUDY ON EFFECTS OF PHYSICO-AND CHEMICO-PROERTIES OF MELTING SLAG ON DETACHABILITY OF SSFCE
1996, 10(3).
[Abstract](2138) [PDF 220KB](75)
Abstract:
The effects of physico-and chemico-properties of melting slag on detachability of self shielded flux cored electrode (SSFCE) are investigated. In physico-properties, liner expansion coefficient is mainly considered. As for chemico-properties, basic index, oxygen content and composition of slag are studied. An equation can be obtained by using ceramics and mineralography which may predict detachability of basic type SSFCE. Other valuable conclusions are also drawn.
HOLE PROFILE AND TUNNELLING EFFECT IN LASER DRILLING
1996, 10(3).
[Abstract](2133) [PDF 303KB](80)
Abstract:
A theoretical model was developted to describe blind hole profiles in Nd:YAG laser drilling. In most cases, the drilled holes resemlbe a spindle-like shape as is predicted by the theoretical model. Derived from the model, an interseting and useful phenomenon: the so-called tunnelling effect, by which cylindrical holes with minimal tapering together with a realtively small heat affected zone can be achieved. The mechanism and the drilling conditions to realize the tunnelling effect are analyzed and experimental evidences are provided.
RESEARCH ON COMBINATION AND PLANNING OF PROCESSING UNITS UNDER CIMS CONDITION
1996, 10(3).
[Abstract](2105) [PDF 239KB](73)
Abstract:
A method of the rational combinging and planning os the given processing machines into units under the condition of computer integrated manufacturing system is presented. Here the modeling method is a kind os queuing network model with the change of productivity, which has been checked in the reality and effectiveness by a manufacturing case in China.