Applied Mechanics and Materials Vol. 197

Abstract: The cyclic test is becoming one of important tests in automotive industry. Various cyclic tests are needed to be done after new concept of product or technology has developed. However it is almost impossible to do same test at same test condition in real situation because it highly depends on test road condition or driving ability of the driver. Therefore, in order to perform same performance test repeatedly, this paper describes about system configuration and path following algorithm for the cyclic test of the autonomous vehicle. The areas discussed in detail include vehicle modification, controller design, system configuration, navigation and path following algorithm. The performance of the test vehicle is also described and evaluated by experiment in real environment.

Abstract: Improvement on noise, vibration and wear in silent chain drives is always an important research subject. However, design methods revealed in public are few because the silent chain shapes are variable and complex. A feasible design procedure is extremely required for improving transmission performance of chain drives. Therefore, a novel design optimization procedure for the rocker-joint silent (RJS) chain and sprocket drive is proposed in this paper. The mathematical models of geometry generation, tooth contact analysis and impact velocities at different mesh stages and chain raise amount in the RJS chain drive have been established. Besides, impact velocities and raise amount which may produce ill effects in the chine drive are incorporated as a multi-objective function to carry out the global minimization trying to find out the optimal design parameters for RJS chain drives. The single-objective optimization trends have also been verified with the previous references.

Abstract: In this research, a kind of clamp for large cylindrical segment slinging and transportation was designed. Instead of the traditional theory that based of friction to slinging and transport, a new designing method that slinging cylindrical segment by grasping double hooks was taken in this research. Parallelogram structure was used to keep the clamp synchronous and horizontal movement. The design process is that Using principles of Parallelogram structure, Parallelogram structure is initially established. Parallelogram structure Motion analysis function of the ANSYS software was used to analyze the motion status of this parallelogram structure under the load. Ensure rationality of design.

Abstract: The mechanism model of a spindle-rotating machine is proposed in this paper according to the mechanism theory.The movement model is established using coordinate transformation,and the solving of this model is discussed.Based on these,efficient algorithms for multi-choice and non-linear errors have been presented.A dedicated post-processor with non-linear error compensation function was developed by VS2010 language.A circle frame cutting experiment was conducted and the result showed that the algorithms was correct.

Abstract: A model is established in this paper about the impact of mass spring on the particle in nonlinear systems with dead-zone and the particle’s subsequent synchronised movement with spring. Simulates are conducted under different conditions, and it is found that when the spring mass is large, the phase plane of particle’s motion trajectories change significantly to the condition when spring is no mass. It is concluded that the spring mass have a great influence on the dynamic behavior of nonlinear systems with dead-zone.

Abstract: Rolling element bearings are widely used in various rotary machines. Most rotary machine failures are attributed to unexpected bearing faults. Accordingly, reliable bearing fault detection is critically needed in industries to prevent these machines’ performance degradation, malfunction, or even catastrophic failures. Feature extraction plays an important role in bearing fault detection and significant research efforts have thus far been devoted to this subject from both academia and industry. This paper intends to provide a brief review of the recent developments in feature extraction for bearing fault detection, and the focus will be placed on the advances in methods for dealing with the nonstationary characteristics of bearing fault signatures.

Abstract: In this paper, the vibration and deformation status analysis of the main beam of the linear vibrating screen under exciting force was done. It’s helpful to make sure about the safety of the linear vibrating screen which was used in the factory. Vibration frequency analysis calculation, strain and main beam deformation status under different frequency orders were analyzed in this paper, based on the simple modeling function of Solidworks software the powerful mode analysis function of the ANSYS software. The conclusion was that this linear vibrating screen was safe enough for the factory.

Abstract: According to the characteristics of automobiles exhaust noise of high pressure level and middle-low frequency, combining sound transfer matrix theory and FEM-Fluid analysis method, simulations of the transmission loss with non-insertion tube expansion chamber muffler, single insertion tube expansion chamber muffler and dual insertion tube expansion chamber muffler are carried out, which obtain the transmission loss curves of mufflers in different structures and different perforation rates. The results show that the max transmission loss and the average transmission loss of the muffler with perforation rate of 5% are greater than that of 3% and 10% below the low frequency of 200Hz; dual insertion tube expansion chamber muffler not only can increase the transmission loss below the frequency of 4000Hz, but also can effectively improve the performance of the mufflers in which have non-perforation tube and single insertion tube at some frequency points. The results of research can provide technical reference for exhaust muffler design of automotive.

Abstract: The change of ambient temperature will cause deformation during the machining process of large-scale aerospace monolithic component. Based on finite element simulation, thermally induced deformation of reinforcing plate is studied in such aspects as reinforcement structure, clamping method and temperature change, and contact function in finite element software is used to simulate the unilateral constraint between workpiece and worktable. The results indicate that reinforcing plate will produce warping deformation due to the change of ambient temperature. Different reinforcement structures and clamping methods have important influence on the deformation positions and degrees, and the deformation is proportional to the temperature change.

Abstract: In a water hydraulic jet pipe servo valve, the overall performance of the valve is directly influenced by the structure dimension of the receiver and the prestage— jet pipe amplifier. This paper deals with the influence rules of the structure dimension parameters and performance parameters on the buildup pressure in the two receiving holes, including the vertical clearance between the nozzle and the receiver, the diameter of the nozzle hole, the diameter of the receiving orifice, and the nozzle offset distance. The best combination of structure size is finally obtained by using numerical simulation, computer emulation and experiment analysis methods. Then build up the finite volume analysis models about the pressure field and the speed field of the jet pipe amplifier. Through analyzing the characteristics of the flow field, a mathematics relation between the jet nozzle offset and the pressure ratio inside the two receiver holes is established, which reveals the energy distribution and conversion mechanism. The conclusion could be an important reference for the design and research of jet pipe servo valve.