Vol. 31 Special Issue
Yumei Wu and Yongli Yu
From the concept of software dynamic evolution, the paper makes a detail analysis of the influence of the software evolution on software mission reliability. The basic question of the software mission reliability for the software evolution is presented. The model framework of software mission reliability is built, and the modeling methods of software mission reliability models are given. The research conclusions have importantly theoretical and engineering value for the reliability analysis and evaluation of the reconfigurable software on function.
Dezhen Yang, Yi Ren, Zili Wang and Linlin Liu
To completely meet the requirements of reliability design in the product designing, an axiom-based Design-in Reliability approach is proposed. In light of the axiomatic design principles, products are designed preliminarily to establish their functional requirements. According to these, functions preserving requirements are augmented, which constitute a Functional Requirement Preserving domain included in functional domain, and derives the parameterized solution for reliability design systematically. Subsequently, the design parameters are augmented and optimized to achieve the functions preserving requirements. Mapping model of the augmented functional domain and the physical domain is established. And a solutions evaluation approach based on Independence Axiom is proposed. Ultimately, via identifying the potential failure modes from the perspective of the disappearance or reduction of functions preserving capability, a control process is elaborated to mitigate the failure modes on the basis of independence axiom and logic decision in order for the reliability requirements to be implemented. Being exemplified by the design of a temperature sensor, the present study demonstrates that all approaches are feasible, efficient, and could be applied in real engineering scenarios.
Yabin Wang, Jianmin Zhao and Xisheng Jia
As systems designed toward larger scale and more complex, more and more maintenance tools are needed in equipment support process. This, however, brings a greater difficulty in making decision to guarantee efficient equipment support actions. In this paper, a category integration analysis method for maintenance tools, which can classify the maintenance tools scientifically by its main characters, is developed. A maintenance tools integration strategy based on the grey situation decision-making method is also introduced. In this method, the integration flow and steps of implementation are given to improve the efficiency of the integration method. The effectiveness of the method is demonstrated via a numerical example.
Wei Guo, Weimin Cui, Tianxiang Yu and Bifeng Song
Sealing reliability plays a very important role in the aviation field. This paper put forward a new sealing reliability analysis method which can be applicable to most of the static seals. For the long-term using rubber seals, it will emerge stress relaxation which may lead to sealing failure. So, it needs to define a stress relaxation factor, which will analyze the sealing reliability taking the stress relaxation into account. Then, set the O-ring as a case, it calculated the static sealing reliability of the O-ring in operating conditions. And it also analyzed the influence of design parameters on the sealing reliability. Finally we found: (1) When the design parameters is certain, the stress relaxation factor, variance and correlation coefficient of the random variables will make a big influence on the sealing reliability; (2) When the design parameters is not certain, the compression ratio and media pressure also have a big influence on the sealing reliability.
Shijing Wu, Jia He, Xiaohua Luo, Kangkang Yang and Zenglei Zhang
In order to solve the low speed of information transmission, inefficient design and long development cycle in the design process of the belt conveyor in the thermal power plants, a multidisciplinary collaborative design System of the belt conveyor is put forward. With the analysis of the information requirement, integrated information model is established with systems accepted by user’s requirements through the network transmission protocol. Project managers can discuss and develop plans through the structure of distributed-centralized. By the framework of information interaction and conflict resolution, professional design personnel can exchange their information and finish the design of the belt conveyor collaboratively.
Shijie Wang, Jie Lu, Nan Zhao, Zengjin Xu and Yuan Li
The crankshaft of 6M50 type reciprocating piston compressor frequently cracked because of torsional vibration. To perform full analysis of crankshaft vibration of the compressor and solve the cracking problems completely, the finite element analysis software is used, and dynamic simulation of crankshaft torsional vibration is developed and analyzed. Finite element modeling process of compressor crankshafts is discussed, and the results of modal analysis for different modification plans are compared. Transient dynamic analysis of the system is performed. The basic cracking reason for crankshafts with different major diameters is explained theoretically by comparison of calculated and practical results.
Peng Zhang, Linpo Su, Xianchun Long and Yonghong Duan
After the completion of pipeline girth welding joint, the joint may be strengthened or softened and high residual stress exists. Most of weld indexes are acceptable, but when pipeline works under inner pressure conditions and the weld joint is in the high-accident risk zone. This paper establishes indirect coupling of pipe 3D pipe multilayer V girth weld based on a weld temperature field and stress field of finite element analysis program. The temperature field simulation results are compared with the experimental and simulation results from some references and those Comparison results are analyzed. The results of residual stress strength joint simulation in operation conditions (0MPa, 5MPa, 10MPa, 15MPa inner pressure) are analyzed and their law of variation is summarized.
Min Ma, Yu Ma, and Shiji Xiaohou
With the development of the LXI technology, synchronization and triggering of LXI instruments has become hot topics in the research world. This paper analyzes five modes of LXI triggering. Combined with Trigger Response Times and Trigger Output Response Times mentioned in LXI Device Specification (Revision1.4), it elaborates the significance of LXI instruments synchronization via LXI Class A and Class B instrument synchronization accuracy test. Besides, taking LXI A logic analyzer for example, it introduces the implementation of LXI trigger interface in detail. According to the result of the LXI instrument clock synchronization experiment, the instruments can synchronize to each other with good precision.
Zhendong Liang and Haibin Li
Based on the research of neural network (NN) computing method of finite element equations for the structure of the discrete model, a complete implementation of the various parts of the computing method is presented. The computation module was described with hardware description language (Verilog HDL) at the RTL level, and functional simulation was executed by Quartus II 11.0 and ModelSim 6.5. Simulation results show that the implementation of neural network computing method based on field programmable gate array (FPGA) can satisfy the requirement of the parallel computing, which could further improve the speed of structural finite element computation, and ensure the speed and accuracy of the computation.
Zhaojun Yang, Chuanhai Chen, Guofa Li, Jili Wang, Xuejiao Du, and Xinhong Zhang
Machining tools are the main equipment for metal machining and consist of mechanical parts, electrical parts and hydraulic parts, and so on. In order to reduce the failures and improve the level of machine tools reliability, the paper firstly performs the failure analysis by the statistical method. Then the failure trends for the key parts of machining center are given using the power law process. In contrast with the usual method, which optimizes the maintenance under the repair costs, an optimization approach of maintenance is presented under the reliability constraints for machining center that used in a northeast manufacturing plant of China. The proposed analysis process could be a useful tool to assess the reliability and optimize the machine tools maintenance policy.