Applied Mechanics and Materials Vols. 602-605

Abstract: Different i nternal microstructure of H –Beam has great influence on the mechanical properties. In order to improve the production technology and improve the mechanical properties of products, H-beam with a residual stress products and without residual stress products are selected and observed by metallographic experiment. The internal microstructure of productions with residual stress and without residual stress are analyzed . The residual stress influence on internal microstructure of H-beam is analyzed.

Abstract: Based on the software of Deform-3D , the finish rolling process of H-beam has been simulated. According to the simulation from result , in the finishing process ,the residual stress of large sized H-Beam is mainly caused by uneven deformation. The big deformation exists in web. The flange deformation is only generated in the rolling surface. This uneven deformation leads to big residual stress in rolling piece.

Abstract: To overcome the deviation caused by the effect of subjective factors in drill wear evaluation, and make the evaluation more accurate and objective, on the basis of drill wear comprehensive evaluation criterion, the projection data are built with projection pursuit method. Two hundred drill wear comprehensive evaluation samples are randomly generated within the range of each class. The projection pursuit model is built by unitary processing according to these samples, which converts the evaluation into non-linear multi-constrained optimization problems. The optimal projection direction vector and the weight coefficient of each evaluation index are obtained with composite simplex method. Meanwhile the corresponding relationship between the region of variation of projection eigenvalue and classification grade is established. The precision of sample evaluation reaches 100% and the evaluation of the measured data achieves good effect. Thus, the scientific evaluation of drill wear is realized by the projection pursuit model.

Abstract: In order to develop a new type of high-performance axial piston pump, the impact of the dynamic response characteristics of piston chamber pressure to the stability of cylinder block were analyzed. This paper a new type of valve plate which combined two fixed throttling grooves with a triangular groove (called three-level gain) was put forward so as to reducing the excessive pressure adjustment of the dynamic response of piston chamber pressure and improving the stability of cylinder block. The simulation results indicate that not only the cavitation is reduced, but also the stability of the dynamic response of piston chamber pressure is remained at various swash plate angle which makes it applicable to variable piston pump. The results also indicate that the flow pulsation of variable displacement pump is significantly decreased in different operating conditions.

Abstract: The higher order crack-tip fields for anti-plane crack oblique to the interface between functionally graded piezoelectric materials (FGPMs) and homogeneous piezoelectric materials (HPMs) are presented. The crack is oriented in arbitrary direction. The crack surfaces are assumed to be electrically impermeable. The material properties of FGPMs are assumed to be linear functions with their gradient direction perpendicular to the interface. By using the eigen-expansion method, the high order crack tip stress and electric displacement fields are obtained. The analytic expressions of the stress intensity factors and the electric displacement intensity factors are derived.

Abstract: Parametric design method of crankshaft is investigated in this study, based on the application of VB environment and CATIA secondary development of automation technology. Using the shape design parameters, the crankshaft can be established parametrically. The research results show that the proposed method can quickly generate crank shape, thus the repetitive operations can be decreased, and the costs can be saved.

Abstract: A large number of wheel and rail profiles of different wear stages are tracked and measured using the wheel/rail profile admeasuring apparatus for DaTong-QinHuangdao heavy-haul line. The finite element method (FEM) models and dynamic models of the contact between wheels and rails are both established for two working conditions (i.e., straight line and curve line). In addition, the corresponding parameters and indexes are obtained through the simulation and calculation. The results show that the maximum equivalent stress for the wheel profile of type II is lower than those of wheel profiles in other stages for the straight and curve lines. Its contact stress distribution is more uniform than others. The dynamics indexes including stationarity and stability of the standard wheel profiles ( i.e. LM) are the best. The indexes are gradually reduced along with the abrasion of wheel profiles. When passing the curve, the dynamics indexes of wheel profiles in each stage are reached the evaluation standard. The abrasion rate of wheels and rails can be reduced relatively when wheels are matched with the worn rails in the stable stage.

Abstract: In this paper, the international common CFD software were installed on the flat three-dimensional optimal design wing tip and winglet wing for three-dimensional simulation, and use the results post-processing software post-processing.

Abstract: The vibration model of on a shaft-bladed system is built undergoing both global motion and elastic deformation by finite element method (FEM).The blade’s dynamic equation in rotating reference frame is established.The various effects are analysed such as Coriolis force,centrifugal force,spin softening,acceleration ect,which have influence to a blade vibtation frequencies in varying degrees.The shaft’s dynamic equation in stationary reference frame is deduced by setting gyroscopic matrix and inertia effects.The beam element model in the shaft-bladed system was set and the critical speeds were calculated.Calculation shows that the effects of the prestress and spin softening have great influence on shaft-bladed system vibration frequencies.The blade’s frequencies decreases slightly because the blade stiffness reduced in the system relatively.The work lays a basic foundation for improving the dynamic stability of the rotor system.

Abstract: Vibration characteristics of surface cracked plate are studied from the view of structural intensity .Line-spring model of the surface crack is put forward based on fracture mechanics. The relationship of the additional angle and displacement with the crack parameters is derived. The concept of additional structural intensity is presented and the additional structural intensity’s expression of shell finite element is deduced. The change regulars between structural intensity and vibration parameters with crack’s parameters are concluded by using ANSYS and MATLAB software, the simulation results are matched with the trend of theoretical formula.