Search results

Guo1,c 1 Department of Mechanical Engineering, Baoji University of arts and science, Baoji 710016, China ahanyuqiang62@163.com, blfz1010@sohu.com, cgguo2006@126.com Key words: industrial overlock machine, multiple-bar linkage, kinematic analysis, the method of successive approximation of link length Abstract.
Introduction The differential feed mechanism of overlock machine have to carry out complicated movements to suit a wide variety of elastic properties of different fabrics, by which the application range of the machine could be expanded.
Feeding is only affected by needle range.
The mainly factors which can affect that is the needle spacing mechanism.
Chinese Journal of Mechanical Engineering, Vol. 17(1981) , p. 68-76.

Then, performance degradation process of gas turbine system for different factors was analyzed.
The results showed that: (1) An equivalent method on contact stiffness of turbine interface was presented, pretightening force is reducing as the result of stress relaxation, that affects contact stiffness of turbine interface
Changes of Material Properties and Life Management of Steam Turbine Components under Long Term Service[J].
Contact Stiffness of Rough Mechanical Joint Surface[J].
Modern mechanical dynamics and engineering application[M].

Numerical simulation of differential injection molding based on Moldex 3D Lilei Miaoa，Pengcheng Xieb, Panpan Zhangc and Weimin Yangd College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China amiaoxinyu@163.com, bxiepengcheng@gmail.com, cpeterpan9152@126.com, dyangwm@mail.buct.edu.cn Keywords: differential injection molding; melt pump; filling length; theoretical basis Abstract.
Introduction Kim[2] carried out a study on the effect of thermo-physical properties, relative humidity and stiffness on the warpage of a PMMA diffusing plate modified with glass fibers in a direct-lit backlight unit of a liquid crystal display.
Conclusion This study is to find the factor affecting the filling volume during the filling stage.
The single factor experimental simulation shows that the influence degree of process parameters on filling volume can be ordered in melt temperature > mold temperature.
China Mechanical Engineering. 13 (2002) 592-596

The microscale effect is beneficial to accurate grasp of all kinds of microscale effect in the forming reasonable classification and evaluation.Change law of microscale affects the nature of knowledge for the right team which provides effective quantitative data, when determine the major hours of rights, it also can provide the guiding idea for material selection and process optimization.The reasonable classification and evaluation of microscale effect is the experience that conventional forming calculation provides a reality way.
All aspects is spreaded to the whole process system miniaturization,. material party and the influence of the main table.Now the flow stress in the process of forming, anisotropy, forming limit and crystal materials of body scale and products relate the size: tiny structures to further spread to the influence of concrete material process,such as the forming force, friction and precision of the springback, burr and products are different with conventional scale , the micro forming process of friction lubrication conditions change, macroscopic in tribology friction theory control method is no longer applicable, the ratio of surface area and volume increase due to a microscopic scale bigger, the influence of friction on the forming is bigger than under macro dimensions, accordingly, lubrication has become a very important factors in the process, lubrication mechanism and macro situation is no longer the same.
Pultrusion products in the fiber content can be as high as 80%, rubber can give full play to the role of the reinforced material under the tension,, the product has high strength; Longitudinal and transverse strength of products can be arbitrary adjusted, can satisfy the use requirement of different mechanical properties of products.No marginal waste appear in production process, product does not need after processing, it saves work , raw materials and energy than other processes, Product quality is stable, good repeatability..
The microscale effect is beneficial to accurate grasp of all kinds of microscale effect in the forming reasonable classification and evaluation.Change law of microscale affects the nature of knowledge for the right team which provides effective quantitative data, when determine the major hours of rights, it also can provide the guiding idea for material selection and process optimization.The reasonable classification and evaluation of microscale effect is the experience that conventional forming calculation provides a reality way.

Introduction One of the most important factors in gaining optimum physical properties of composite resins is an adequate polymerization [1].
Kruskal-Wallis statistical test result (p values) when compared different composite resins hardness in each light-cure mode Ramp mode Constant mode Pulse mode G C F G C F G C F G - 0.02 0.02 - 0.02 0.02 - 0.02 0.02 C 0.02 - 0.00 0.02 - 0.00 0.02 - 0.00 F 0.02 0.00 - 0.02 0.00 - 0.02 0.00 - G- G-aenial; C- Charisma; F- Filtek Z 250 Discussions The inorganic fillers included in the resin matrix of composite material determine the physical and mechanical properties of the composite.
The factors that could be related with surface microhardness of composite resin are: the size of the filler, the volume occupied by the fillers in the resin, the nature of the filler and the way in which the filler was obtained [14, 15].
Okuno, The effect of filler loading and morphology on the mechanical properties of contemporary composites.
Ştefănescu, Stuctural Properties of Nanofilled and Microfilled Restorative Composites, Mat.

Various factors account for the irregular width ,such as nonuniform motion and irregular cutting of the weldment edge.
Welding beading not only affects the welding line beauty,but also always covers the slag inclusion and lacking of penetration which may lead to flaw.
And it distribute in different layers which will decrease the mechanical property of the welding joint.
And it will decrease the mechanical property of the welding joint.
[5] Yanhong Zhang, Mechanical and Electrical Product Development and Innovation, 2 (2003), p. 27-29.

Factors that may cause wrinkling in deep drawn parts are summarised as follows: l Blank holder force.
Preliminary experimental results in the multi-pass ISF process showed that the process variables affecting wrinkling behaviour are similar to those in deep drawing, as summarised as follows: l Blank holder force.
The aims of this study are first to clarify how the process variables affect the wrinkling deformation in multi-pass ISF process and then to analyse the wrinkling formation mechanism.
Blank holder force also affects the lateral hoop stress, which further leads to wall wrinkling and tearing.
Meehan, Experimental investigation of mechanical properties, formability and force measurement for AA7075-O aluminium alloy sheets formed by incremental forming, Int.

On the one hand, the air gap formed between the casting and the mould during solidification of the melt leads to the complexity of heat transfer; on the other hand, the heat transfer between the casting and the mould is affected by many factors that are difficult to quantify, such as enclosed strength on spindle, the geometry of the casting, and the roughness of the contact surface.
Meshing of two-dimensional models for calculation 3.3 Thermal properties and boundary conditions In order to accurately simulate the cooling process, it is of primary importance to obtain accurate thermal parameters of castings and moulds[9].
This method is simple in concept and is suitable for general one-dimensional two-dimensional models with temperature-related physical properties.
This gap significantly reduces the heat flow between the casting and the mould, affecting the internal grain growth rate of the casting.
During the actual casting cooling process of molten tin, due to the great difference in temperature and thermal properties between the casting and the refractory mould, the heat of the surface after liquid tin filling is rapidly diffused into the refractory mould, and then the heat is slowly diffused through the mould and the insulating medium.

result in an overall deterioration of the component mechanical properties.
Thus, estimation of the heat damaged layer thickness and its structural morphology, which affects the resultant properties of the machined surface, became an important concern to predict service life of machined components since components machined by µEDM such as micro-dies are often subjected to severe cyclic pressure and temperature loadings.
Current results suggest that properties of µEDM'ed surfaces are much more similar to the properties of conventional EDM'ed surfaces.
Summary Properties of µEDM'ed surfaces are found to be much more similar to the properties of conventional EDM'ed surfaces.
Rahman, Influences of pulsed power condition on the machining properties in micro EDM.

The Micro-analysis about the Morphology and Characteristics of the Ball Mill Slag Powder Tao YE1, a, Peng JIA2,b, Bin JIANG3,c 1,2School of Mechanical and Electronical Engineering, WHUT, Wuhan 430070, China awhyetao@hotmail.com, bjiapenglg@163.com, c14.bin@163.com.
The quality of image segmentation will directly affect the follow-up study.
The main purpose of the image threshold in accordance with a gray level particles, it is divided pixel again, so that each adjacent area of particle has uniform properties, and the threshold selection is particularly important, it determines an image segmentation success or not.
Tab.1 Micro- appearance Quantization Parameter of Slag Morphology quantitative parameters computing method Shape factor Roundness factor Flat degree Edge angle Surface roughness P represents the perimeter of the grain boundaries, A represents the particle size, L and B respectively represents the maximum and minimum particle diameter Fred, represents minimum circumscribed polygon perimeter of particle, represents the circumference of the equivalent ellipse.
Tab. 2 Micro- appearance Quantization Result of GBFS Parameters Grinding time The average shape factor The average factor of roundness The average degree of flat The average angle of edge Ag Surface roughness 5min 2.460094 0.65935 2.539048 1.545127 1.71675 10min 1.779947 0.666454 2.368288 1.265975 1.56131 15min 1.589298 0.669378 2.018109 1.054925 1.458074 20min 1.187282 0.673551 1.791028 0.931079 1.377043 From the table, results showed that: (1) With the extension of the ball mill grinding time, the slag powder group shape index, flatness, angularity and surface roughness were decreased, roundness coefficient increases, the morphology of slag powder will become more spherical; (2) The shape index of slag powder particles reflect the contour features, K become the greater indicates that the more complex the shape of the particles, the shape index was significantly decreased and roundness coefficient no significant change after segmentation; (3)The size of particles shadow