Applied Mechanics and Materials Vols. 71-78

Abstract: Based on the analysis of character of load-transfer of super-long pile, for the purpose of pile settlement control, critical pile length for single friction super-long pile was calculated by Cooke’s shear deformation-transfer model, because the assumption of Cooke’s model is similar with working condition of super-long pile. In the analysis, compression of pile is taken into account. Then, the design chart of critical pile length for super-long pile is provided for normal design index. Lastly, the critical pile length of an engineering example is analysed by the method, the calculated results have agreed well with the field measurement. The analysis show that critical pile length is greatly concerned with ratio of Young’s module of pile and soil, the greater the ratio is, longer the critical pile length is. Pile diameter also affects the critical pile length, the larger the diameter is, longer the critical pile length is. In addition, the critical pile length of super-long pile is concerned with shaft resistance distribution along the pile.

Abstract: As a new energy-saving and environmental protection building material, dry-mixed mortar has been promoting actively in China. The key techniques of control system for dry-mixed mortar production line were introduced in this paper, which was mainly based on PLC and smart weighing instrumentation. Firstly, the technology process and control demands were presented. Secondly, control system configuration, control strategy were proposed in detail. Finally, the key intelligent adjust algorithms were described as well. The practical operation verifies that the control system is highly reliable and stable, and it greatly enhances the level of automation and weighing accuracy of the raw material and meets the equipments requirements of energy-saving and green running.

Abstract: Since the eighties of last century, the single individual project is gradually taken place by programs. The program management challenges the traditional methods and technologies for management as programs are much more complex than the single individual projects. In order to improve the program management performance, the essay comes up with the adoption of the new information technology cloud computing in program management. Based on the example of Shanghai 2010 Expo, we come to the conclusion that the application of cloud computing can highly improve the performance of program management with its powerful capacity.

Abstract: Statically indeterminate frame, composed of beams and columns, is a widely used structure form in civil engineering. The frame carrying capacity under various actions is related to the absolute stiffness of frame components and relative beam-column line stiffness ratio. The matrix displacement method and programming based on MATLAB were employed in this study to calculate the internal forces and displacements of a 2-bay 2-story frame structure under the action of horizontal loads. The influence of the beam-column line stiffness ratio on the frame load capacity was discussed based on the calculated result. Furthermore some advises were provided about the reasonable beam-column line stiffness ratio for engineering design.

Abstract: In this paper an optimal maintenance policy for a Reactor Protection System (RPS) for a nuclear plant was developed. RPS consists of continuously operating sub-systems that were subject to random failures. A block system diagram for RPS had been proposed that facilitates analyzing of individual sub-systems separately. The proposed maintenance policy is the Age Replacement model, which incorporated both corrective and preventive maintenances. A Markov model was used to optimize the preventive maintenance interval of those sub-systems whose failure and repair rates were exponentially distributed. Finally, a sensitivity analysis had been performed and recommendations for maintaining the required RPS availability have been suggested.

Abstract: For the further study of bearing compressive capacity of GFRP tube filled with SHC（steel-reinforced high-strength concrete）columns subjected to eccentric compression, and analysis its whole bearing compressive process under eccentric compression. Based on the flat section assumption finite strip method, the calculating program of bearing eccentric compressive capacity of GFRP tube filled with SHC columns is proposed according to existing retrofit theory and related technical procedures. The relation curves of load-deformation is gotten using this calculating program, at the same time it can get the effect curves of concrete strength, slenderness ratio, eccentricity and containing bone rate to load-deformation. Calculations show that the ultimate bearing compressive capacity of composite column decreases with the increase of slenderness ratio, and elastic stage of component curve gradually shortens and stiffness gradually loses; The ultimate bearing compressive capacity of composite columns decreases with the increase of eccentricity; component ductility improves; the ultimate bearing compressive capacity of composite columns increases with the increase of concrete strength. The calculated results agree well with the experimental results and this study provides a basis for practical design.

Abstract: In this paper, optimal scheduling on logistics task and logistics resources for the port logistics alliance operations is discussed, the logistics service cost and time of each node is comprehensively considered, in order to establish a multi-objective optimization model. At the same time, improve genetic algorithm in use of the advantage of tabu search climbing ability to design a genetic taboo hybrid algorithm, which enhances the solution efficiency. Hope this study can effectively realize optimal allocation on logistics resources and tasks for port logistics alliance.

Abstract: Based on the theory of Fisher discriminant analysis, this paper aims to develop the Fisher discriminant function model by using the representative water inrush data from the floor of coal mining face, considering comprehensively the factors that affect the water inrush from coal floor. The predicted result is consistent with the actual situation, which corresponds with or better than that of the least squares support vector machine, artificial neural network, and so on. The results indicate that this model is a new effective way of predicting the water inrush from floor and can be widely used in the practical engineering because of the low resubstitution error rate and good distinguishing performance.

Abstract: Study was carried out on the disadvantages of QR method while calculating structures and programming currently. According to its basic idea, the necessary condition for more simplification was pointed out. In the process of simplification, the shape function matrix and node displacement were calculated and saved only for parts of elements, the element stiffness matrix and load array were divided into sub-blocks, thereafter, these sub-blocks were multiplied by coefficients of certain items, finally assembled into the spline-discretization stiffness matrix and load array according to the series and spline knots number that were corresponding to nodes. One model was calculated by QR program with the method simplified or not and other methods. Results prove that this simplified approach is correct, feasible and suitable for structure calculation. It has a good theoretical and practical value.

Abstract: The nonlinear Ball-beam system combine with a CCD camera is studied in this paper. The images which include Ball-beam system and a ruler are collected by CCD sensor. The image is segmented using the adaptive image binarization threshold algorithm, and then the ruler, the ball position and the pointer position are extracted from the image. The ruler is scaled and the pointer position is also calculated. Finally, the value of pointer position is input into Ball-beam system as an expected ball balance position. A Fuzzy self-tuning PID controller and a BP neural network PID controller are designed for ball balance stable control. After experimental, the Ball-beam balance control in any position can be fulfilled using both of algorithms.