| At present,with the vigorous development of China’s national defense construction,the military capabilities are also constantly improving. To make the operational capability of the armored vehicles strong,it requires less faults and higher reliability.The research topic of this thesis comes from the research project.The analysis methods of system reliability are used to analyze the reliability on the hydraulic system for the amphibious armored vehicle,it is a very important reference to help the designers to design more reliable hydraulic products and the maintenance personnel to overhaul the system faults more quickly and effectively. Considering to the lacked fault statistics of the hydraulic system for the amphibious armored vehicle,it can’t directly reflect the results with the traditional reliability analysis method. Based on the results of hydraulic system reliability analysis, it can improve the safety of the design of hydraulic pipeline through the fluid-solid coupling simulation analysis of the hydraulic pipeline under the actual working conditions and checking the strength of the hydraulic pipeline.According to the problems mentioned above,at first,this paper introduces the concept of fuzzy, combine the fuzzy mathematics with the traditional reliability to form the fuzzy reliability analysis.Take the hydraulic system of the amphibious armored vehicle as the research object,carry out the Fuzzy Fault Tree Analysis(FFTA) and Fuzzy Failure Mode,Effects and Criticality(FFMECA).And then,aiming at the analysis results above, the fluid-solid coupling simulation analysis is conducted,the main research contents are as follows:(1) Through the comprehensive analysis on the structure and working principle of the hydraulic system for the armored vehicle,draw its structure principle diagram.And through the analysis on all the components function of the system,drawing the reliability block diagram of its task.(2) Combined the working principle diagram of the hydraulic system, according to the statistics of the failure mode,be access to relevant documents and establish the system fault tree, through the qualitative analysis of fault tree,find out the minimum cut set.And combine the fuzzy theory,use the triangular fuzzy number to do the fuzzy quantitative analysis of the system,calculate the fuzzy probability confidence intervals of the top event and the fuzzy importance degree of each bottom event. According to the results of the analysis,it is helpful to find out the important failure modes of hydraulic system for armored vehicle.(3) On the basis of fuzzy tree analysis,use the fuzzy FMECA method to the fuzzy comprehensive evaluation for the hydraulic components and its failure mode.Have the Quantitative calculation to get the comprehensive hazard degree of the hydraulic system and its hydraulic components and failure mode.(4) This paper studies the fluid-solid coupling modal analysis method and the fluid-solid coupling transient analysis method of the finite element simulation,and the accuracy of the method is verified by the examples.Discuss the effect of fluid pressure and piping materials for the natural frequency of the fluid-solid pipeline,and different thickness and entrance velocity for the deformation and pressure of the fluid-solid pipeline.(5) On the basis of the fuzzy reliability analysis results for the hydraulic system,the finite element analysis software ANSYS is used to conduct the fluid-solid coupling modal analysis and the fluid-solid coupling transient analysis about the hydraulic pipeline for the armored vehicle,and check the strength of the pipeline,estimate the design safety. |
