Applied Mechanics and Materials Vols. 494-495

Abstract: Mechanical execution system is an important part of mechanical system that contributes to the delivery of system function. There is currently no conceptual design model that is specifically for the conceptual design of mechanical execution system. Based on the FBS (Function-Behavior-Structure) model, this paper investigates the characteristics of the conceptual design process of mechanical execution system, and subsequently proposed an FTPBM (Function-Technology-Process action-Motion behavior-Mechanism) model for its conceptual design. The model includes a functional prototype and six steps of design procedure as well as a number of design synthesis strategies and methods. A design case of press machine is also studied, which demonstrates the proposed model to be not only practicable, but also improve the designers innovation capability.

Abstract: A thermal mechanical coupled model for High-Speed rail screw spike had been established with the aid of FE software Deform-3D by using rig id-plastic FEM. According to the results of finite element simulation, the metal flowing rules in plastic deforming were discussed. Stress and strain field distribution of Screw Spike were concrete researched. It has important theoretical sense and using values on solving part precision forming and workpiece quality improvement of plat cross wedge rolling.

Abstract: The vibration isolators have witnessed significant developments due to pressing demands for high resolution metrology and manufacturing, optical, physical and chemical experiments. In the view of these requirements, the engineers and physicists have exploited different types of vibration isolators. This paper firstly presents the recent developments on the passive vibration isolators. It finds that the passive vibration isolators can constrain the high frequency oscillation. The active control is the efficient method to cancel the low frequency vibration. Then, the paper is concerned with the recent advances on the active vibration isolator. The appropriate actuator, sensor and advanced control method are the key component of the active vibration isolator to enhance their vibration isolation properties. Finally, the author proposes that the magnetic suspension vibration isolator is a future research direction in the field of the vibration isolation.

Abstract: As there is no sufficient support between the single moving tool and fixture, the formed metal sheet is easy to bend in single point incremental forming (SPIF). Double sided incremental forming (DSIF) is proposed in which two tools are used on each side of the sheet to improve the components forming accuracy. Element finite method is introduced to simulate the forming process with both DSIF and SPIF toolpaths and the component geometric accuracies are compared. The simulation result shows the DSIF toolpaths can obtain better geometric accuracy than SPIF.

Abstract: To study the effect of ignition mode and position on fragment velocity of azimuthal warhead, a simulation model was established and computed. Simulation analysis results of azimuthal warhead showed that two ignition points mode was more valuable than the three ignition points mode, the fragment velocity curve had increasing trend in 0°~180° radial direction, ignition positions near to the edge of main charge end had the highest performance-cost ratio in the practical application.

Abstract: Plastic deformation resistance is a basic parameter of mechanics parameters in press work theory and technology. In this paper, the influencing factors of deformation resistance are analyzed and the model of deformation resistance is established. The deformation resistance can be calculated by program with Lagrange interpolation method. This result provides evidence for calculating mechanics parameters and designing metalworking equipment.

Abstract: s. The purpose of this paper is to propose one of methods to measure utilization of component about mechanical system with adaptable functions. The method is based on the incidence matrix between functions and components of those mechanical systems. And cost of components is considered in this method for further expressing comprehensive utilization. Finally a case of adaptable-function pliers is studied to illustrate the feasibility of the method.

Abstract: Stiffnend panels are used to investigate the fracture behavior of the fuselage components within the framework of the damage tolerance analysis. Integral structure are gradually replace butilt-up structure in recent years. This paper presents an improved method based on displacement compatibility principle to calculate stress intensity factors. A finite element method based on intgral contour is introduced and used for verifying the solutions. Stress intensity factor solutions of built-up structure and integral structure were both calculated using these two methods. From the comparison, these two solutions are in good agreement both in built-up structure and integral structure.

Abstract: In this paper, by using a self-developed transient aerodynamic thermal simulation system, the thermal protection performances of metallic honeycomb panel were tested at different transient heating rates, with a maximum instantaneous temperature reaching 950°C. Furthermore, a three-dimensional finite element model was established to determine the thermal protection performances of the metallic honeycomb panel in different simulation environments with high heating rates. The fact that the numerical calculations agreed well with the experimental results is a good foundation for replacing certain expensive thermal experiments with numerical calculations. The results of this research provided important reference values for the design of the thermal protection system comprising metallic honeycomb panel structures.

Abstract: Cutting temperature always highly reaches over to 1000°C when high speed machining with PCBN tools. Diffusion of tool material element may have important influence on tool wear at such high temperature, the diffusion wear and oxidation wear have become the major wear mechanism. In this paper, the rules of diffusion wear and oxidation wear for PCBN cutting tools are proposed and analyzed based on thermodynamics theory. Dissolution concentrations in typical normal workpice materials of PCBN tool material at different temperature are then calculated. Diffusion reaction rules in high temperature are developed and analyzed using Gibbs free energy criterion. The machining tests were conducted using the PCBN tools at different cutting speeds of 50, 95,100 and 180 m/min, feed of 0.1, 0.2 and depth of cut of 0.1, 0.8, 1, and 1.5 mm respectively on PUMA300LM numerically-controlled lathe. It was found that the theoretical results were uniform with the experimental data; the results will provide useful references for tool material design and selection.