Papers by Author: Hong Lin Zhao

Abstract: Self-healing is the most important feature of smart distribution network. This paper analyzes the mathematic model and the optimization scenario of the loop closing power supply switching operation in the self-healing frame. An effective distribution network loop closing optimization strategy is proposed, which is significant for reducing loop closing operation risk and increasing the stability of power supply.

Abstract: All-Electric Subsea Production Control System, which has many advantages over conventional Multiple Electric-hydraulic control system, is the development tendency of subsea production control system. Being based on principle of all-electric control system, its advantages, working principle and key technologies were analyzed in this paper, which could be a reference for further study.

Abstract: Onshore hydraulic systems are not generally applied in subsea production control system,so how to design a special needed hydraulic system for subsea X-tree has been one of the hot research questions.Several specific hydraulic components were analyzed, such as hydraulic power unite,umbilical,subsea control model,hydraulic control valve and valve actuator, and then corresponding hydraulic schematic which can meet the requirements of subsea X-tree is presented.

Abstract: The parameters of joint parts must be included in the finite element model of a whole grinding machine. The subject investigated in this paper is B2-K3000 high-precision composite flexible grinding machine. Through finite element modeling, the joint part parameters are integrated into the whole grinding machine model to establish a dynamic model and then analyze its static and dynamic characteristics. The result shows that the whole grinding machine possesses good features, but it still needs to be improved. This paper gives suggestions for its structure development and application.

Abstract: It is commonly used method to analyze the overall thermal characteristics of mechanical structure without considering the thermal contact resistance of components. But in terms of precision composite grinding machine, the impact of thermal contact resistance can not be ignored. On the basic of thermal contact resistance characteristics, this article gives the concept and empirical value of the equivalent area factor. By calculating the equivalent contact coefficient, the thermal contact resistance characteristics were integrated into the grinder simulation. According to the structure and processing characteristics of grinder, grinding machine was analyzed in two parts respectively to get the pattern of temperature rise and thermal deformation. Analysis shows the impact that thermal deformation has on working accuracy, so as to provide basis to the compensation of numerical control system to improve the working accuracy.

Abstract: Contact heat transfer are widely used in mechanical system and research on thermal contact resistance is a significant link in engineering application. In this article, main influencing factors of thermal contact resistance such as material characteristics, contact pressure, surface roughness, intermediate medium had been further researched by experimental methods, and the relations between pressure and thermal contact resistance had been taken under different materials, different suface processing quality and different medium. Several other problems related to thermal contact resistance had also been discussed. The research contents provide reference for the application of thermal contact resistance and reasonable design of mechanical structure.

Abstract: After modeling and calculating of whole machine, the static and dynamic characteristics are obtained, since it is difficult not only to judge out machine components’ influence on machining precision intuitively , but also to identify the weak link of the whole machine. Therefore, through extracting key nodes coordinates of machine components and deformation information of finite element software calculated, we brought forward a space vector transfer algorithm, calculated the contribution of components for tools and work piece system and expressed impact of machine components on tool and work piece system by histogram. By this means ,we can judge out the whole machine’s weak links intuitively. Take XK713B Vertical Milling Machine as the case research object, extract key nodes and their deformation information of general structure such as lathe bed , column, headstock, sliding table, workbench etc. By using space vector transfer algorithm, the result shows that the largest contribution to tool system and workbench system is column, which is the weakest link in the whole machine and its vibration type is swing. According to this, further optimize design of column can be proceed.

Abstract: A design method of structural optimization of large part of machine tools was proposed based on neural network and finite element method. With the pillar of XK713B numerically-controlled boring and milling machine as an example, the BP neural network model corresponding to structure parameters and dynamic characteristics of the pillar was built, and rapid sampling of the neural network model was carried out with the help of APDL language. Then, optimization of the design variables was done and satisfied results were obtained. Calculation results show that, by using the neural network model, error between calculation results and expectations is less than 5%.

Abstract: The bridge plug is a staple tool used in downhole operation and the performance of the slips has a directly influence on the oil well productivity and production safety. We raised an optimize method based on BP network and genetic algorithm to make sure the slips satisfy the high temperature and high pressure demands. Establishing the slips system and making finite element analysis by ANSYS, abtaining sixteen group datas to constitute the BP network training samples, establishing the BP simulation model reflecting curvature radius of the slip fluke, dip angle of the fluke, angle of the fluke and distance between flukes using nonlinearity mapping ability of the neural network, applying optimize design for the simulation model using global optimization ability of the genetic algorithm and abtaining the optimum structure parameters of the slip. The optimized results indicate the whole performance of the slips system has increased notably.

Abstract: Based on finite element analysis software ANSYS, the deformation and force condition of the rubber sealing o-ring pre and post with back-up ring under different oil pressure conditions was analyzed. The von mises stress distribution of the o-ring and the change of contact pressure between o-ring and sealing interface pre and post with back-up ring under different oil pressure conditions were discussed. The results show that, the maximum von mises stress of the o-ring is smaller and the maximum von mises stress of the sealing system concentrates on the left top and the right bottom of the back-up ring after using it; the o-ring will not be extruded into the gap of the groove because of the existence of back-up ring which prevents gap-bite and prolongs service life of the o-ring; the contact pressure between o-ring and sealing interface increased, thus the sealing reliability of the system increased.