Advanced Materials Research Vols. 201-203

Abstract: Tooth broken, oil leaking and bearing burnt have influenced the original running of a 45T mining car which adopted one two-class gear reducer. In order to solve these problems, a three-class gear reducer was developed and its strength and stiffness were validated by using experience formulas and FEM. The sample of the three-class gear reducer was manufactured and tested in practical work for more than a half year. The results show that the three-class reducer works well, and the problems occurred in the two-class one can be resolved.

Abstract: Dump truck subframe is an important bearing components which is used for connecting the chassis frame and the cargo compartment, and the rationality of its design has an extremely important influence on performance of the entire vehicle, moreover, the use of CAE technology can optimize the design of the subframe. In this paper, using solid element as basic element, the finite element analysis model of dump truck frame is built up with the software ANSYS, the static characteristics of the subframe under bending mode, twisting mode, braking mode and lifting mode are studied. The dynamic characteristics of the subframe are also analyzed, the stress parameters under static characteristics, the natural frequency and the corresponding mode shape characteristics of the subframe under dynamic characteristics are obtained, the improved advice of structural design for the subframe is proposed.

Abstract: In view of the problems existing in the present transportation ways of coal mine, a kind of new auxiliary haulage system has been designed, which can achieve the going there and back transportation only by using one winch in the multi-slope and undulating roadway. And according to the requirements of safety production of coal mine, the non-wheeled supply mine car without anti-car device and the safety interlock system of wheeled supply mine car have been designed. Meanwhile, finite element analysis software is adopted to check and analyze the locking pawl strength of the safety interlock system with wheeled supply mine car. The analyzing result shows that the locking pawl can completely stand the impact loading when the mine car sliding down. The haulage costs and the occurrence of security incidents have been reduced when the designed system is applied to coal mine. Engineering practice shows that the good results have been achieved.

Abstract: Aimed at resource-restrained project scheduling problem under uncertainty which is a hot research spot, a kind of real-time feedback scheduling method is presented in this paper. Before a project is executed, the scheduling plan of all subtasks is made according to ascertain condition. The running procedure of the project is monitored by a workflow management system. When a situation, in which the finish time of the project will be delayed by changed running condition, is detected, the related information is fed back to a scheduling controller; And the controller calculates the controlling data according to optimal objective and then sends it to object scheduled; And then the old plan is rescheduled The concept model for real-time feedback scheduling of cooperative design project with resource-restrained is setup. When only the finish time of subtask is influenced and it is described as interval number, its corresponding mathematic model is setup and converted to an ascertain one by possibility-level, and solve it by GA(Genetic Algorithm). The structure of this GA is given, and a method of chromosome coding, that is the chromosome is segmented according to resources and gene is sorted in task-series, is presented in this paper. A computational example is studied in this paper, the results reveal that the method presented is valid.

Abstract: At present the study on the application of the topology optimum design in scraper conveyor is still under development. In this paper the topology optimization based on the Solid Isotropic Material Penalization (SIMP) is applied to the design of the middle pan, which can provide a valuable conceptual design scheme for the selection of the middle pan pattern. In conjunction with the homogenization theory and Finite Element Method (FEA), the mathematical models for designing the middle pan by maximizing the rigidity are developed in this paper. By applying the topology optimum design to the middle pan, the topology optimization based on the SIMP method is proved to be reliable and practical at the conceptual design stage of middle pan.

Abstract: The State Grid has proposed to construct a strong smart grid to solve the resource scarcity, environmental pollution and other social problems, which will certainly drive the development of green energy, such as wind energy, solar energy, tidal energy and biomass energy. The study will build a Green Power System Assessment Model (GPSAM) using multivariate statistical analysis to optimize the energy resources of a region and finally to provide reference for the construction of a new plant or the plant expansion to get the balance of environment benefit, economic benefit and social benefit.

Abstract: Numerical optimization method is increasingly applied into the design of machine tools so as to improve their performance. This paper employs Monte Carlo optimization method to predict and reduce the errors of ultra-precision machine tools in term of motion errors between cutting tool and workpiece closely associated with machine processing of ultra-precision machine tools. Using a quite different origin position of location coordinate system from traditional in that every ideal frame on current body is coincided with the reference actual one on the adjacent body, the motion errors are expressed in homogeneous matrix defined with adjacent bodies’ residuals in multi-body system analysis. This expression clearly shows that the final position errors are decided by the motion accuracy of the guideline, and gesture errors are affected by accuracy of the spindle assembly. With geometric errors extracted from the matrix, a new optimization method of error allocation is presented to maximize the machine precision by reasonable distribution of tolerances key parts. Using variables intimately related to motion errors and under constrained by cost, optimization model is established, then it is solved with Monte Carlo simulation method to compute top ten key factors contributed to errors and obtain distribution probabilities of both position error and gesture error. Case study formulated is reported to illustrate the method proposed and to evaluate its effectiveness.

Abstract: The parameters are provided by meeting designing requirement and machining technology in traditional design of scroll profiles. This design method is single objective optimization. It is very difficult to get optical design scheme. In fact the design of scroll profiles is a multiple objectives optimization problem. In this paper a cost function is designed. It can guarantee not only lower friction loss power and leakage loss power but also higher efficiency. In a practical example, scroll profiles optimization was realized based on CPSO. The outcomes show this method is good enough and can be applied popularly.

Abstract: Balance head is a key component of grinding wheel auto-balance device. The key issue is to design a balance head with high accuracy and durability. Considering these two factors, a new type of balance head with non-contact driving structure is proposed and described in this paper.

Abstract: a new 4-axis machine tool, which is used to relief grind sphere gear hob including spherical hob, elliptic hob and arc surface hob, is developed. The principle of machining of spherical hob is introduced first. Transmitting system, numerical system and some key techniques are then introduced. The machine tool can be reconfigured when machining of arc worms and spatial cams beside of machining spherical hob. Four forms of the machine tool for machining different workpiece are also introduced.