基于时域仿真的飞机燃油管道卡箍振动疲劳分析

近年来,随着飞机性能的逐渐提高,管路系统的设计理念不断完善,对管路的卡箍也提出了更高的可靠性要求。基于这种情况提出了一种基于时域仿真的飞机管道卡箍振动疲劳寿命分析方法,该方法的优点在于振动响应和疲劳分析均在时域进行,减小了频谱分析所带来的误差。基于梁单元模型建立了管道有限元模型,在随机激励下,通过时域数值积分法进行了管道系统动力学分析,发现振动最大的卡箍,并输出卡箍位移载荷时间历程。建立卡箍实体有限元模型,利用瞬态分析的方法仿真在卡箍振动位移载荷作用下的振动薄弱环节应力,得到危险点应力时间历程。在时域利用雨流计数法编制载荷谱,并运用线性累计损伤理论,进行了卡箍疲劳寿命仿真分析。针对某型飞机发生了卡箍断裂故障的燃油管路,对管道进行了卡箍优化,并建立了该段管道的试验模型,在振动台上进行了振动试验,试验结果验证了仿真分析的准确性,说明了该方法的有效性以及工程实用性。

Vibration Fatigue Analysis of Aircraft Fuel Pipe Clamp Basedon Time Domain Simulation

In recent years, with the gradual improvement of aircraft performance , the design conceptof the pipeline system has been continuously improved, and higher reliability requirements have beenput forward for the clamp of the pipeline. Based on this situation, this paper proposes a vibration fa-tigue life analysis method for aircraft pipe clamping based on time domain simulation, and the ad-vantage of this method is that the vibration response and fatigue analysis are carried out in the timedomain, which reduces the error caused by spectrum analysis. A pipe finite element model is established based on the beam element model. Under random excitation, the dynamic analysis of the pipeline system is carried out by the time-domain numerical integration method, the clamp with the grea-test vibration is found, and the time history of the clamp displacement load is output. The finite element model of the clamp body is established , the stress of the vibration weak link under the influ.ence of the vibration displacement load of the clamp is simulated by the method of transient analysis.and the time history of the stress at the dangerous point is obtained. The load spectrum was preparedby rain-flow counting method in the time domain , and the linear cumulative damage theory was usedto simulate the fatigue life of the clamping. For the fuel pipeline where a certain type of aircraft hasa clamp fracture failure, the clamp is optimized, the test model of the pipeline is established and theyibration test is carried out on the shaker table. The test results verify the accuracy of the simulationanalysis, and explain the effectiveness of the method and the practicality of the project.