Applied Mechanics and Materials Vol. 274

Abstract: A novel constant tension yarn feed control system for automatic winder is presented in this paper which is based on analyzing the principle of the generation of yarn tension and the factors which make the tension fluctuate. DSP28035 made by TI (Texas Instruments) is adopted as the main control unit of the system to acquire the real-time yarn tension which is transmitted from a yarn tension sensor. Intelligent PID (proportional-integral-derivative) algorithm is also adopted to achieve a high-dynamic performance and an ultra-low inertia servo motor speed digital control to realize constant yarn tension feed. The system not only have the function of tension setting, over current protection, error detection and alarm, but also possess the features of simple structure, low cost, real-time control and high accuracy.

Abstract: The probability of hazard of amusement rides is divided into 5 categories according to characteristics, and the degree of risk hazard is divided into 5 categories. The risk matrix of amusement ride was created according to risk matrix model. The risk categories were created according to the values of matrix elements. The risk knowledge table was created according to all links of life of amusement ride.

Abstract: A new constitutive model which is modified from Gao’s constitutive model has been introduced to analyze the finite deformation of a circular membrane with an embedded rigid inclusion under uniform pressure. Based on the basic controlling equations, the constitutive parameters and the dimension of the rigid inclusion have been discussed to demonstrate the influences on the membrane stresses.

Abstract: In this paper, the laser is used as light source and interacted with the solution of milk powder; scattered light-to-transmitted light ratio is used to characterize the milk macromolecules. At first, this paper analyzes the theory of scattered light-to-transmitted light ratio，and a relation model is preliminarily built between the macromolecules and the ratio, then the parameters of the model are fitted through self-made experimental device. The relation model between the fat and protein of milk and the ratio is established.

Abstract: Super capacitor charging voltage changes linearly: the initial stage of charge, the super capacitor voltage rises quickly, the middle of change is relatively flat, after the rise again accelerated phase voltage fluctuations in charge of the initial and end of charge; charge currentthe larger the full charge time is short, to verify the characteristics of high current fast charge of the super capacitor.

Abstract: This article takes the existing maize harvesters in the market as the example to discuss about the problems on its design, color and function. By means of the Humanity Design which is more according with people’s psychological needs on the design, color and function of the maize harvesters, it could apply to the Agricultural Machinery all the more.

Abstract: The dynamic coefficients and film pressure effect in rotor-bearing systems may lead to an unstable station. The mechanism of the dynamic coefficients and film pressure induced thermal instability in the rotor-bearing system has been studied. The journal bearing model is adopted for the derivation of analytical expressions. The results show that the rotor speed has some effect on bearing dynamic coefficients and film pressure.

Abstract: To obtain exact analytical solutions of differential equations of gear system dynamics due to the difficulty of solving complicated differential equations. Only the approximate analytical solutions can be determined. The method of multiple scales is one of the most powerful, popular perturbation methods. The dynamic model which describes the torsional vibration behaviors of gear system has been introduced accurately in this paper. The differential equation of gear system nonlinear dynamics exhibiting combined nonlinearity influence such as time-varying stiffness, tooth backlash and dynamic transmission error (DTE) has been proposed. The theory of multiple scales method has been presented in solving nonlinear differential equations of gear systems and the frequency response equation has been obtained. The fact that the approximate analytical solution by using the method of multiple scales is in good agreement with the exact solutions by numerically integrating differential equations has proved that the method of multiple scales is one of the most frequently used methods in solving differential equations, especially for large and complicated differential equations.

Abstract: The simulation research on gas turbine generator set has the important practical significance for its main development direction in marine power plant. The research object is semi-physical simulation for marine gas turbine generator set. This paper presents a new type of semi-physical simulation scheme based on “hardware agent” through reviewing the existing the structure characteristics and deficiency of semi-physical simulation system of gas turbine device. The theoretical basis and operation control strategy and framework of the new project were discussed. The experiments on sudden load-up and load rejection were made based on new type of semi-physical simulation system for marine gas turbine set and had a good test effect.

Abstract: The ball screw is a main driving component in the CNC machine tools. The ball screw’s structural performances and working conditions will have an important impact on the machining accuracy of CNC machine tools. However, the previous research method can not suffice the precise results’ requirements. So it is very necessary to do an in-depth analysis of the ball screw, which use dynamic research and be combined with the FEA software ANSYS. This article uses the above methods to do the modal analysis, and then gets the intrinsic frequency and the vibration model. It will make an important significance for guiding the practice.