Advanced Materials Research Vol. 819

Abstract: Additional power head with common milling machine.Two and a half axis CNC system are used for CNC grinding circular surface curve trajectory. The advantages of this processing method are: We can avoid the influence on processing of lead screw clearance because of changing the parts clamping position,effectively ensure the integrity of the great circle arc curve trajectory. Because of using digital control technology in grinding process is instantaneous automatic compensation of grinding wheel wear, the machining accuracy of parts in outline is improved, the machining error is decreased. it will effectively ensure the consistency of the large circle curve precision.This method has the effect of infer other things from one fact for CNC grinding of large circular arc curve parts. Broaden the scope of application of CNC technology and practical.

Abstract: This paper presents an adaptive tool path generation method for Fused Deposition Modeling (FDM). The proposed method consists of three steps. First, an adaptive slicing considering both surface quality and building time is proposed for following tool path generation. Second, a hybrid tool path strategy is introduced to improve the boundary contours accuracy. This step is an adaptive process to choose an appropriate proportional relationship between the two types of tool paths according to the specific fabrication requirements. For further improvement, a tool path adjustment is employed on the original tool paths. A case study of a sliced layer is used to verify the feasibility and advantage of the proposed method.

Abstract: Granular particle damping technique is a means for achieving high structural damping by the use of metal particles filled into an enclosure which is attached to the structure in a region of high vibration levels. The particle dampers are now preferred over traditional dampers due to the stability, robustness, cost effectiveness and the lower noise level than the impact damper. Such a promising technique has been used successfully in many fields over the past 20 years. In this paper, a state-of-art review on the development of modeling for particle damping is presented. The fundamentals and individual features of three main mathematical models of the granular particle damping are briefly summarized, i.e. the lumped mass model, the Discrete Element Method (DEM) and the approach based on the multiphase flow (MPF) theory of gas-particle. It is worth noting that an improved analytical model of the particle damping based on MPF theory is also introduced. The co-simulation of the COMSOL Multiphysics live link for MATLAB is conducted using this improved model. It can be shown that this model makes the complicated modeling problem more simply and offers the possibility to analyze the more complex particle-damping vibrating system.

Abstract: With the rapid pace of urbanization, more and more people begin to pay attention to environment protection. Green design has long been an area of concern. The foundation of design is the material. The paper firstly emphasizes the benefits of the green design and then explores the development and application of new materials. From the cases listed in the paper, it is not difficult to find out the social progress driving force and the new energy generation promoted by the design. Besides these, this paper also presents the methods of green design, the switch from materialization to dematerialization, the design theory drawn from the essence of traditional green materials, the popularity of the advanced forming technology of green materials and smart materials and the significance of the visual, tactile experience and users psychology in design. At last, this paper generalizes the basic function and great value of the materials role in green design.

Abstract: The dynamic performance of modern machine tools is more and more highly emphasized. The research purpose of this paper is to research dynamic performance of gantry machining center through modal experiment. In this paper, the theory of relative excitation test on the machine tool is expounded, and relative excitation test is carried on gantry machining center and then the modal parameters of this machine tool are obtained through experimental modal analysis. Analyze the weak link of this gantry machining center, show that the stiffness of Z direction of Z to feed component of this machine tool is insufficient and the stiffness of X, Y direction of ram is insufficient.

Abstract: For different three-axis machining characteristics, SolidCAM provides many machining strategies including linear, correction, spiral, imitation cutting and so on. This paper chooses three-axis revolving curved surface parts as the research object and reference three-axis stereo processing combinating wrap-around roughing and linear processing. Finally, the cutting model of this machining strategy based on parameters has been established to provide a reference for the determination of cutting parameters.

Abstract: The error distribution of a machined NURBS surface is complex to describe since the machined surface isnt that easy to obtain. A new method for machined NURBS surface description based on inspection database of on-machine probing is presented. The main idea is to approximate the machined surface using the inspection data and the basis functions of the nominal NURBS surface and to get the error distribution of the surface. A virtual part with a NURBS surface is presented and its error caused by the interaction of the machine-tool-workpiece is obtained using the FEA method at the inspection points. A machined NURBS surface is achieved and the error distribution of the surface is expressed. This method provides a new way in error compensation and it will improve the machining accuracy of a NURBS surface.

Abstract: With the evolution and degradation of mechanical fault, changes of the structural inherent characteristics will directly affect the overall response of system. Spur gear, which worked as the research object, is to be explored on the changes of modal parameters under different damage state. Optimum driving-point mobility and modal parameter identification is achieved by comprehensive utilization of experimental modal analysis and finite element analysis. is used to determine the experiment results is whether accurate or not. Then comparing with the differences of modal parameters, the preliminary judgment of gear damage can be made. According to the experimental data of different gears, theis taken to complete the correlation analysis and to judge the degree of the damage. The results shows that provide an effective basis for the identification of vibration mechanism and vibration characteristic of fault gear.

Abstract: This paper uses the FE (finite element) and experimental hybrid modeling method to establish the dynamic model of the spindle system. Calculate and analyze how static stiffness, span, and cantilever length affects mode frequency and mode shapes. Analyze the effect of the flywheel on dynamic performance based on harmonic respond. Moreover, the effect of the flywheel is well testified by experiment.