Applied Mechanics and Materials Vols. 84-85

Abstract: Recent concrete specifications often require the use of combined aggregate gradation that meets the “8-18” band gradation. But theoretically “8-18” band covers a wide range of aggregate variation which may result in variable properties of concrete. To avoid this drawback, two new band gradations were proposed, these are, “5-10-14-18” and “5-10-18-22” bands. This paper analyses different aspects of these proposed bands through a number of concrete mix results.

Abstract: Insufficient welding or bad welding of motor armature is one of the main faults of motor armature. With the help of the application of multi-agent technology in the fault diagnosis system of motor armature to detect insufficient welding or bad welding, the intelligent description of the various faults has been enhanced, also, the capacity of fault diagnosis of the system have been greatly optimized and improved. In this paper, we first analyses the characteristics of the fault of motor armature with insufficient welding or bad welding, by which the characteristics of the fault are identified. Next, we introduces agent and multi-agent system. Finally, the building of fault diagnosis system based on multi-agent technology is discussed.

Abstract: In this paper, an approach for multivariate statistical process monitoring ans fault diagnosis based on an improved independent component analysis (ICA) and continuous string matching (CSM) is presented, which can detect and diagnose process fault faster and with higher confidence level. The trial on the Tennessee Eastman process demonstrates that the proposed method can diagnose the fault effectively. Comparison of the method with the well established principal component analysis is also made.

Abstract: Because of the complex structure of grader working device, its optimization is a repeated, continuously improved process. A new model has to be set up before each optimization. In order to solve the problem of repeating modeling and improve the product optimization efficiency, a second development system of working device is established. Parametric driving about working device is realized in term of spatial mechanism. At first, the overall design framework of this second development system was established, then customized user interface was completed based on UG/Open API and parametric programs about the working device system were complied based on UG/Open Grip subsequently. The connection among customized user interface, parametric programs and human-computer interaction was realized by using Visual C++, the integrated second development system design of working device was eventually completed. This second development system could not only provide engineers with a rapid design method to shorten the new product development cycle, but solve the problem of repeating modeling during optimization design as well.

Abstract: This paper addresses a kind of maximum power point tracking (MPPT) control for a single solar power generation systems use the Takagi–Sugeno (T-S) fuzzy-model-based approach. In detail, we consider a dc/dc buck converter to regulate the output power of the photovoltaic panel array. First, the system is represented by the T-S fuzzy model. Next, give an approximate desire state of the photovoltaic panel array according to estimating calculate. Next, a fuzzy MPPT controller is proposed to achieve the given state. Then a popular traditional Perturbation & Observation Method (P&O) is used to change the given state. Finally, numerical simulation results will be given to demonstrate the performance of the proposed methods.

Abstract: Distinct element method (DEM) is based on Newton's second law of motion and the basic law of particles between elements colliding. It's an effective numerical method which widely used in many engineering fields by using dynamic relaxation method on Iterative calculation. By comparing the linear contact model and nonlinear contact model of DEM, Cundall spring-damp-sliding contact model had been selected as our major studying model. Then the coordinate of the contact point, “composite quantity” of each contact unit and the relative velocity between units in this system had been calculated. And finally the numerical simulation on the motion state of single granule and granule group had be done.

Abstract: Regarding a 300mm practical mill as the research object, the mathematical model of the hydraulic AGC system in the mill is established. Experimental results show that the model is simple and reliable. It is useful for analyzing the impact of various factors on the plate thickness. It has important theoretical significance for such system’s optimal design and analysis.

Abstract: Position-limit protection equipment is the major control equipment on CNC machine, whose logic control method is the assurance of normal work of position-limit protection equipments. It will reduce the effect of position-limit protection or cause it malfunction, if we apply the logical control method not suitably. Current CNC machines are provided with a positive control limitation protection device, and then it is likely to happen malfunction even cause accidents due to its electric circuit errors or its open circuit. In order to solve this shortcoming, somebody has worked out a new method, which is called negative logic control. This paper introduces the new logic control method’s basic principle and its practical usage.

Abstract: With the gradual increasing consciousness of reducing the CO₂ emission around the world, more and more attention are paid to the study of CDM project and the methodologies which are used to determine the amount of Certified Emission Reductions. Based on the approved methodologies, we study the application of the methodologies to the practical situation of the renewable energy for the base stations. That provides very good foresight in combining the CDM project with the ICT industry technology.

Abstract: Rolling is an undesirable motion for ships. Large amplitude rolling can easily lead to capsize which will cause the loss of life and property. This paper proposes a fuzzy-extension control strategy for ship roll damping and anti-capsizing system. Fuzzy control strategy is studied in the classical domain for rudder roll stabilization to solve uncertainties in quantitative change and gradual change resulting from the change of ship model parameters so as to improve control performance. Moreover, the real-time tuning algorithm is presented to tune the fuzzy rules. Extension control strategy is studied in extension domain to solve the uncertainties in non-gradual change arising from the wave so as to extend anti-capsizing control sphere. Every control strategy can realize effective control within the scope of control.The two intelligence control methods are combined to increase the level of intelligence of system. This paper carries out the simulation under various situations such as different navigation speed, sea conditions, encounter angle and ship parameter perturbation, to test the roll reduction and robustness of the roll controller designed.