某辅助动力装置燃油总管裂纹故障分析

Failure Analysis of Fractured at Fuel Manifold in Auxiliary Power Unit

某型辅助动力装置燃油总管采用聚四氟乙烯软管,在外场发生裂纹故障,裂纹部位在金属管接头与聚四氟乙烯内管的接触处。采用断口分析并利用ANSYS进行管路装配应力仿真计算对燃油总管裂纹故障进行了分析。结果表明,燃油总管装配应力较大是引起疲劳裂纹的主要原因。基于应变能最小原理,提出了一种管路装配的改进措施,可有效减少管路在装配时的应力集中。

Fuel manifold with PTFE hose in an auxiliary power unit fractured at the end of pipe junction between the metal joint and the PTFE inner pipe.The failure cause of the manifold was analyzed by fracture surface observation and fuel manifold assembly stress simulation calculation on ANSYS.The result show that the fatigue fracture of the fuel manifold mainly result from excessive assembly stress during assembly.Base on principle of minimum strain energy,put forward a improved pipe assembly method,the assembly stress should reduce.