Research on Vibration Modal Experiments of Aero-engine External Pipes
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摘要: 为分析不平衡振动对航空发动机外部管路结构影响,构建管路的真实与简化模型,通过双应变片传感器测试管路振动模态试验方法研究两端固支长薄壁管路的振动特征,并对管路模型有限元仿真计算比较。结果表明:简化与真实模型的试验结果基本一致;两种模型主振型均为1弯、2弯、3弯;两种模型固有频率除第1阶管路两端不能完全固支约束差异大外,后2阶在10%误差内;试验结果与仿真结果保持一致。振动模态试验方法对材料参数不全构件振动特征分析,助于管路结构优化与特征精确预测。Abstract: To analyze the influence of unbalanced vibration on aero-engine external pipes, based on the construction of a real pipe model and a simplified model, the paper probed into the vibration characteristics of the long thin-walled pipes fixed at both ends of the engine with the pipe vibration modal experiment method. And a comparison was made between the experimental result and that obtained through the finite element simulation analysis of the pipe model. It proved that the results obtained from the simplified model and the real model were basically the same; the main vibration types were single bending, double bending and triple bending; the inherent frequency differences of the two models accounted for no more than 10%, except that the differences among the first order were considerable because of its adjacency to both ends of the pipe; the experimental results were in line with the simulation ones. The paper concludes that the vibration modal experiment method can be used in the analysis of the vibration characteristic of the components with incomplete material parameters, which will be helpful for the optimization of the pipe structure and actual prediction of its vibration characteristics.
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Key words:
- aircraft engines /
- vibration /
- modal analysis /
- experiments /
- structure optimization /
- natural frequencies /
- external pipe
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表 1 某型发动机外部管路外形及固定连接结构
序号 系统类型 结构外形 固定方式 连接类型 1 ATA-73燃油系统 直管
1弯管:短管(<90°、180°~360°)、长管(<90°)
2弯管:异面短管(<90°)、长管(<90°)
3弯管:异面长管(<90°)
4弯管:异面长管(<90°)单管U型卡箍螺栓固定
单管机匣L型支架螺栓固定
单管机匣U型卡箍L形支架螺栓固定
双管双头U型卡箍固定
双管U型卡箍L型支架固定喇叭形管
接头螺纹
连接2 ATA-75空气系统 直管
1弯管:长管(<90°)
2弯管:长管(90°~180°)、异面短管(90°)
4弯管:长管(90°~180°)、异面短管(90°~180°)单管皮带与支架固定
夹环螺栓固定
L型支架螺栓固定
带塑料套管双C型夹簧卡箍螺栓固定
双管夹簧卡箍固定喇叭形管
接头螺纹
连接3 ATA-79滑油系统 直管
2弯管:异面长管(<180°)
3弯管:异面长管(90°)
4弯管:长管(<180°)带塑料套管双夹簧卡箍螺栓固定
U型卡箍螺栓固定或法兰4螺栓固定
L型支架螺栓固定
双管双头卡箍固定喇叭形管
接头螺纹
连接表 2 两端固支管路的模态参数值
阶数 真实模型 简化模型 两模型比较 固有频率/Hz 阻尼比 结构主振型 固有频率/Hz 阻尼比 结构主振型 固有频率差异/% 阻尼比差异/% 1 48.83 0.041 5 管路两侧弯曲叠加为1弯主振型, 一侧1上弯, 另侧1下弯 92.77 0.038 1 1弯曲主振型, 位于振型中部 89.99 -8.19 2 351.56 0.008 4 两侧弯曲叠加为2弯主振型, 一侧1上弯1下弯, 另侧1下弯1上弯 327.15 0.006 7 2弯曲主振型, 1上弯1下弯 7.46 -20.24 3 649.41 0.007 1 两侧弯曲叠加为3弯主振型, 2下弯1上弯 659.18 0.007 2 3弯曲主振型, 2下弯1上弯变形 1.48 1.41 表 3 管路的试验和仿真结果分析
阶数 试验计算值 阶数 试验计算值 两种方法结果比较 固有频率/Hz 结构主振型 固有频率/Hz 结构主振型 1 92.77 1阶弯曲 1 139.75 1阶弯曲y+方向 固有频率:仿真值偏离试验值, 最小值与试验值相差46.98 Hz, 占比33.62%。主振型:试验值与仿真值基本一致, 前者示出1阶弯曲主振型, 后者示出x+、x-、y+、y-方向1阶弯曲振型。 2 146.32 1阶弯曲x-方向 3 185.43 1阶弯曲y-方向 4 192.91 1阶弯曲x+方向 2 327.15 2阶弯曲 5 384.17 2阶弯曲y+方向 固有频率:仿真值偏离试验值, 最小值与试验值相差57.02 Hz, 占比14.84%。主振型:试验值与仿真值基本一致, 前者示出2阶弯曲主振型, 后者示出x+、x-、y+、y-方向2阶弯曲振型。 6 400.53 2阶弯曲x-方向 7 506.62 2阶弯曲y-方向 8 525.63 2阶弯曲x+方向 3 659.18 3阶弯曲 9 749.16 3阶弯曲y+方向 固有频率:仿真值偏离试验值, 最小值与试验值相差89.98 Hz, 占比12.01%。主振型:试验值与仿真值基本一致, 前者示出3阶弯曲主振型, 后者示出x+、x-、y+、y-方向3阶弯曲振型。 10 777.82 3阶弯曲x-方向 11 981.44 3阶弯曲y-方向 12 1 015.10 3阶弯曲x+方向 -
[1] Pittard M T, Evans R P, Maynes R D, et al. Experimental and numerical investigation of turbulent flow induced pipe vibration in fully developed flow[J]. Review of Scientific Instruments, 2004, 75(7):2393-2401 doi: 10.1063/1.1763256 [2] Guo L, Wei J J. Structural damage detection based on BP neural network technique[C]//Proceedings of 2010 International Conference on Intelligent Computation Technology and Automation. Changsha, China: IEEE, 2010: 398-401 https://www.researchgate.net/publication/251942938_structural_damage_detection_based_on_bp_neural_network_technique [3] 李占营, 王建军, 邱明星.航空发动机管路流固耦合振动的固有频率分析[J].航空发动机, 2017, 43(1):66-70 http://d.old.wanfangdata.com.cn/Periodical/hkfdj201701012Li Z Y, Wang J J, Qiu M X. Analysis for natural frequencies of pipe conveying fluid considering fluid-structure interaction[J]. Aeroengine, 2017, 43(1):66-70(in Chinese) http://d.old.wanfangdata.com.cn/Periodical/hkfdj201701012 [4] 刘清友, 路军, 陶思宇, 等.单弯管系统直管段振动特性实验研究[J].科学技术与工程, 2017, 17(3):322-327 doi: 10.3969/j.issn.1671-1815.2017.03.053Liu Q Y, Lu J, Tao S Y, et al. The vibration characteristics of the single elbow system about straight pipe[J]. Science Technology and Engineering, 2017, 17(3):322-327(in Chinese) doi: 10.3969/j.issn.1671-1815.2017.03.053 [5] 刘阁, 陈彬, 张贤明.化工管路系统的耦合振动瞬态特性研究分[J].机械科学与技术, 2010, 29(3):312-317 http://www.cnki.com.cn/Article/CJFDTotal-JXKX201003009.htmLiu G, Chen B, Zhang X M. A study of the transient coupling vibration characteristics of a chemical piping system[J]. Mechanical Science and Technology, 2010, 29(3):312-317(in Chinese) http://www.cnki.com.cn/Article/CJFDTotal-JXKX201003009.htm [6] Durali M, Fazeli A, Azimi M. Investigation of dynamics and vibration of a three unit pig in oil and gas pipelines[C]//Proceedings of 2008 International Mechanical Engineering Congress and Exposition. Boston, Massachusetts, USA: ASME, 2008: 265-275 http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1643609 [7] He K, Zhu W D. A vibration-based structural damage detection method and its applications to engineering structures[C]//Proceedings of 2011 International Mechanical Engineering Congress and Exposition. Denver, Colorado, USA: ASME, 2011: 497-510 doi: 10.1080/19475411.2011.594105 [8] Bernasconi G, Giunta G, Chiappa F. Gas filled pipelines monitoring using multipoint vibroacoustic sensing[C]//Proceedings of the 34th International Conference on Ocean, Offshore and Arctic Engineering. St. John's, Newfoundland, Canada: ASME, 2015: V05BT04A046 http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2465790 [9] Feng X, Zhou J. Structural damage detection with vibration characteristics for subsea pipelines[C]//Proceedings of the 33rd International Conference on Ocean, Offshore and Arctic Engineering. San Francisco, California, USA: ASME, 2014: V04AT02A047 http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1911637 [10] 赵伟志, 陈志英.燃油管路系统振动特性有限元模拟技术分[J].航空发动机, 2016, 42(1):42-47 http://d.old.wanfangdata.com.cn/Periodical/hkfdj201601009Zhao W Z, Chen Z Y. Research on finite element simulation technology of fuel pipe system vibration characteristics[J]. Aeroengine, 2016, 42(1):42-47(in Chinese) http://d.old.wanfangdata.com.cn/Periodical/hkfdj201601009 [11] 李占营, 王建军, 邱明星.航空发动机空间管路系统的流固耦合振动特性[J].航空动力学报, 2016, 31(10):2346-2352 http://d.old.wanfangdata.com.cn/Periodical/hkdlxb201610006Li Z Y, Wang J J, Qiu M X. Dynamic characteristics of aero-engine pipe system considering fluid-structure coupling[J]. Journal of Aerospace Power, 2016, 31(10):2346-2352(in Chinese) http://d.old.wanfangdata.com.cn/Periodical/hkdlxb201610006 [12] 谭博欢, 舒宝, 李冬, 等.流体引起的空调管路振动分析与实验研究[J].振动与冲击, 2017, 36(1):261-267 http://d.old.wanfangdata.com.cn/Periodical/zdycj201701038Tan B H, Shu B, Li D, et al. Analysis and test for fluid flow induced vibration of air conditioner pipes[J]. Journal of Vibration and Shock, 2017, 36(1):261-267(in Chinese) http://d.old.wanfangdata.com.cn/Periodical/zdycj201701038 [13] 谭博欢, 李越峰, 李冬, 等.空调配管理论模态分析与试验研究[J].机械科学与技术, 2016, 35(8):1195-1200 http://journals.nwpu.edu.cn/jxkxyjs/CN/abstract/abstract6464.shtmlTan B H, Li Y F, Li D, et al. Finite element and experimental modal analysis on connecting pipes of air conditioner[J]. Mechanical Science and Technology for Aerospace Engineering, 2016, 35(8):1195-1200(in Chinese) http://journals.nwpu.edu.cn/jxkxyjs/CN/abstract/abstract6464.shtml [14] 樊洪海, 杨行, 彭齐, 等.基于传递矩阵法的高压气井生产管柱固有频率分析[J].科学技术与工程, 2015, 15(4):84-89 doi: 10.3969/j.issn.1671-1815.2015.04.017Fan H H, Yang X, Peng Q, et al. Natural frequency analysis of high-pressure gas well production strings based on the transfer matrix method[J]. Science Technology and Engineering, 2015, 15(4):84-89(in Chinese) doi: 10.3969/j.issn.1671-1815.2015.04.017 [15] 彭刚, 于乃江, 贾文强.航空发动机外部管路的结构与动力学特征参数分析[J].航空发动机, 2017, 43(5):1-6 http://d.old.wanfangdata.com.cn/Periodical/hkfdj201705001Peng G, Yu N J, Jia W Q. Analysis of structural and dynamical characteristic parameters of external pipes for aeroengine[J]. Aeroengine, 2017, 43(5):1-6(in Chinese) http://d.old.wanfangdata.com.cn/Periodical/hkfdj201705001 [16] 杨莹, 陈志英.航空发动机管路流固耦合固有频率计算与分析[J].燃气涡轮试验与研究, 2010, 23(1):42-46, 25 doi: 10.3969/j.issn.1672-2620.2010.01.008Yang Y, Chen Z Y. Calculation and analysis on natural frequency of fluid structure interaction in aero-engine pipelines[J]. Gas Turbine Experiment and Research, 2010, 23(1):42-46, 25(in Chinese) doi: 10.3969/j.issn.1672-2620.2010.01.008