Applied Mechanics and Materials Vol. 618

Abstract: The fracture pump will vibrate remarkably in the operating process due to the complex combined loads. It is necessary to study the dynamic performance of its whole structure so as to ensure its safety and operating efficiency. Therefore, the ANSYS was applied to conduct harmonic response of a certain three-cylinder fracture pump and study vibration response by mechanical excitations of a crank-connecting rod-piston system. It was shown that the acceleration amplitude of fracture pump is very large in some frequency and easy to resonate, such as 77.35Hz, 126.7Hz, 744.6Hz and 792.2Hz. Some tests were implemented to validate the feasibility of the FEM method in the dynamic response analysis of the fracture pump, on their basis the optimal design became possible for the fracture pump.

Abstract: Robotic catheter minimally invasive operation requires control system of quick response, strong anti-jamming and real-time tracking of target trajectory. The contradiction between fuzzy PID control precision and its response speed limits its application in master-slave minimally invasive operation. The paper adopted variable universe fuzzy PID method to improve fuzzy PID method’s control precision without reducing the speed of response. The simulation results show that variable universe fuzzy PID control method has fast tracking performance and strong robustness, and it has feasibility and practicability in robotic catheter minimally invasive operation.

Abstract: This paper conducts a study on a pre-mixed micro abrasive water jet machining system. A new kind of abrasive mixing tank and the jet system are designed and tapped for the pre-mixed micro abrasive water jet machining system. The performances of the pre-mixed micro AWJ machining system are tested, and some polishing experiments are conducted for hard-brittle materials such as silicon nitride. The results show the feasibility and the advantage of the pre-mixed micro abrasive water jet machining system for polishing hard-brittle materials.

Abstract: Vehicle operation safety monitoring system (5T system) is the important means to guarantee the safe operation of the vehicle under the new situation of mixed passenger and freight rail transportation, speed, vehicles overloaded. The system using a variety of advanced motion detection technology, information processing technology and network technology to achieve real-time vehicle dynamic monitoring of running status. However, various types of failure of vehicle components are interacting and interrelated, in practical applications, there is a strong demand for information sharing, centralized monitoring and comprehensive analysis. Based on the actual research of Datong-Qinhuangdao line, a set of building methods of 5T information fusion are proposed, laid the foundation for the promotion of 5T information fusion.

Abstract: The paper presents an assessment methodology for comparable evaluation of a Spar and a Barge support with multi-megawatt OWT. Stability and hydrodynamic performance of both two floaters are checked by SESAM software. Taking consideration of rotational excitation frequencies of the OWT and primary wave excitations, reasonable engineering attributes of the structures are derived. The attributes are applied in multi-criteria decision making method-TOPSIS combining with environmental and economic attributes for benchmarking relatively better solution. The outcome of the study would contribute towards a more informed decision making process for the most suitable configuration of a new floating support structure for large wind turbine at deeper water.

Abstract: The nanofluidic devices with the nanopores are the foundation of the third generation of the DNA sequencing technology. Comparing with the traditional nanopores constructed on the nanofilms, the nanofluidic devices made by the SiO2 have higher stiffness, strength and stability. We study on the structure design of glass capillary tension feed system, used in manufacture of the nanofluidic devices with the nanopores. Firstly, we design glass capillary tension feed system, including the mechanical moving parts, heating parts and the control parts, which is used to heat glass capillary and stretch it to get glass capillary with a smaller inner diameter in need. Among them, the control accuracy of the moving parts is up to 1μm, the heating range of heating parts is less than 5mm, and the temperature can reach 1500 ̊C. Then we make a prototype, and do some experiments with it. According to the experiment results, the system can be used for glass capillary tension, and the inner diameter of the nanoglass capillary stretched by this system is as small as 500 nm.

Abstract: At present, the height measure is an important content of image processing. But the height is determined by solar height angle achieved by look-up table, and the method is imprecise and inconvenient. To overcome such drawbacks, a novel determination method was proposed in the paper. First, the imaging time is adjusted to Solar Time. Then, the solar height angle at imaging time is calculated. Finally, the height of an object is calculated based on solar height angle and shadow length. The theoretical analysis and experiment results show that the proposed method is more effectual.

Abstract: Scissor lift platform had lots of kinematic pairs and the mechanics relations between them were complex. So mechanics analysis became the focus by researchers. The mechanical model of scissor lift platform under the action of combined loads was built in the paper. The calculation formula of nodal force of scissor transmission unit was given used the transfer matrix method. The calculation formulas of drive units were given on the virtual work principle. Also the calculation method of nodal forces of drive units was given. How the different distributions of drive unit influence on the nodal force was analyzed. The drive units’s position optimization method was given in this paper. In order to verify the reliability of this calculation method, an calculation example of typical structure was given. The calculation results given by the method in this paper was identical with the result given by finite element method. The conclusions obtained could serve as theoretical guidance and reference for mechanical analysis and optimal design of scissor transmission mechanism.

Abstract: The objective of the article is the energy efficiency assessment of an energy-saving measures complex on the basis of calculation-and-experiment control of building energy-saving. An experimental determining of energy indices of multi-apartment residential building during heating period was carried out. The energy audit was carried out applying express method which allows reducing significantly the labour intensity as well as the duration of the field observation. The thermal energy consumption for heating and hot water supply as well as electrical energy consumption during heating period were determined on the basis of the energy audit results. The energy efficiency class of the building is С (normal). Thus it has been stated that the building inspected conforms to the normative requirement. The verification of the calculation method for building energy indices during heating period was conducted on the basis of experimental investigations results, which confirmed the method reliability. The method for calculating the building energy indicators during the heating period including the consumption of thermal energy for heating and hot water supply and the electrical energy consumption was developed. Based on the calculation results it is possible to show that decrease of building envelope air permeability allows to raise a class of building energy efficiency.

Abstract: In the old oilfields, Reservoir properties have a certain change in the long-term effects of the injected water, studying variation of reservoir parameter in different injection stage has important Significance, it can help to determine the distribution of remaining oil in different washing stage and make reasonable recovery methods. In this paper, combined with experimental data from a large number of samples in different washing stage and numerical analysis method, the variation of parameters of different reservoirs in different washing stage is analyzed, the conclusion includes: With the water washing degree increasing, flow capacity of class I reservoir increased gradually; There is rapid growth under a certain degree of water injection condition, the aim reservoir is divided into four classes. In the class III and IV reservoirs, average pore throat radius is less influence by washing. Water washing degree has the least impact on class I reservoir and there has the greatest impact on class IV reservoir. The influence of washing level is the greatest on the class I reservoir and the poorest on the class IV reservoir.