Advanced Materials Research Vols. 945-949

Abstract: For research on comprehensive performance of crankshaft in piston compressor, multi-body dynamics model was built to get mechanical boundary conditions of the crankshaft, and the fatigue strength was verified; Finite element model (FEM) of the crankshaft was established, and the 1^st 6 modal of the crankshaft was obtained. The results showed that fatigue strength and dynamic characteristic of the crankshaft was qualified. Theoretical basis could be provided for optimize the crankshaft’s structure by fatigue strength and modal analysis.

Abstract: Since the work conditions of the crankshaft are complicated and the crankshaft interfaces are very weak, strength analysis of crankshaft interfaces is very important. Three dimensional finite element model of the crankshaft is built for strength analysis of the crankshaft interfaces. The crankshaft has three interfaces. During the analysis, contact problem is taken into account. The results show that the maximal stress of the crankshaft is 535MPa, which is less than the yield limit of 1Cr11Ni2W2MoV steel (993MPa). Therefore, the crankshaft interfaces can not be broken during the work of caterpillar tractor.

Abstract: The escapement mechanism in a mechanical watch movement plays a critical role. Its purpose is to maintain and count the oscillations of the balance wheel. The timekeeping accuracy is therefore regulated. The motion of the escapement mechanism is highly complicated and no in-depth study on its kinematics has been done by now. This paper investigates the kinematics of the Swiss lever escapement which is used in almost all mechanical watches. One half cycle of the motion is described in different phases. Mathematical models for each key component are developed. Simulation result shows that the model is precise in describing and predicting the motion of the escapement. This method is essential for improving and optimizing the design.

Abstract: Graphic method and analytical method are often used for calculation analysis of kinematics and dynamics of the crank-rocker mechanism. However, the analysis procedure is usually complicated and the analysis results can not be expressed visually and directly. Programs are made on the basis of theoretical analysis of kinematics and dynamics in this paper, and a kind of analyzing system of crank-rocker mechanism is designed with Java. This system may analyze the crank-rocker mechanism’s motion state, stress condition and its change regulation in different operating conditions, as well as different rotation angles of the crank. This system has also a friendly man-machine interface. Calculation results are expressed through textbox and parametric curve. Each window of the system has the following buttons: calculation button, save button, output curve button, print button, maximum/minimum value output button and exit button. This system may evidently reduce the calculation workload and improve working efficiency.

Abstract: Fork joint fracture of mill universal coupling directly affect the normal production, Using FEM software ANSYS analyzed the structure strength of fork joint of universal coupling. The results indicated the Stress concentration of the fork joint under the most dangerous working conditions. The analytical results accorded with actual status in a certain extent. The modified design prevents the joint fracture.

Abstract: Introducing the particle damping technology into the gear transmission will effectively reduce the vibration during gear engagement, especially suitable for high temperature, oil-lubricating environment for the gear transmission system. In the real working situation, centrifugal load will make the particle at one end away from the rotation center. The vibration suppression of particle damping in the gear transmission is studied through experimental method. The effect of rotation speed and particle filling rate on vibration suppression of particle damping is analyzed in gear transmission. The result will provide exact theory basis and design principle for the vibration suppression of gear transmission.

Abstract: Nonlinear bearing forces of ball bearing under five-dimensional loads are given, and five-DOF dynamic equations of rotor ball bearing system are constructed. Bifurcation of periodic motion of rotor ball bearing system in unbalance-rotating speed and radial clearance-rotating speed parametric domains are studied by use of continuation-shooting algorithm. Results show that the way of bifurcation and stability of period-1 motion vary with radial clearance and unbalance.

Abstract: Noise of building life, residential areas environmental equipment and residential district external seriously interferes with the normal life of the residents, the sources and the mechanism of noise generation are analyzed, technical measures of multi family residential building noise are put forward.

Abstract: The main goal of the present paper is to provide a method of source identification. Firstly, statistically optimal near-field acoustical holography (SONAH) techniques are applied to locate sound sources with the reflected sound field. In the presence of reflection plane parallel and perpendicular to the source plane, the incoming wave and reflected waves are separated based on the acoustic superposition principle and acoustic mirror image principle to satisfy the condition of the sound sources reconstruction using SONAH. Secondly, contribution of noise source to the special field point is analyzed and noise source ranking of interior panel groups are evaluated based the proposed three step acoustic contribution method. Finally, this method is verified experimentally.

Abstract: Semi-submersible plays an important role in ocean oil and gas exploitation. This paper carried out a model test for motion response of a deepwater semi-submersible in regular waves with the model oriented in the head, beam and quartering directions. The results were presented as Response Amplitude Operators (RAO) of the platform. Dynamic responses measured in the model test were compared with the numerical results obtained by the software HYDROSTAR. Results show that the numerical results generally tally well with the experimental measurements. This illustrates the accuracy of the numerical results, and proves that the numerical results are reliable to be the reference of judging performance of the platform.