摘要:本文对带弹性阻尼支承的转子系统由于丢失叶片产生的瞬态响应给出了系统的实验研究结果。进行了不同转速和不同挤压油膜阻尼器(SFD)油膜间隙情况下转子上施加不同的突加不平衡量的实验。在阻尼器处由极限圆表征的不稳定门限值可以确定;全面地观察到转子系统由于非线性引起的一些特殊现象,如“锁死”、双稳态跳跃和亚协调进动等。分析了SFD抑制转子系统不稳定的有效性和能力。

摘要:通过寿命预测与试验研究,对材料性能到构件的特异性、循环蠕变的分析和平均应力的影响,提出了处理的办法。对交互作用规律进行了深入的分析,提出了预测寿命的途径。

摘要:介绍的物光正弦调制法是给振动物体的基座以低频振动,相当于物光位相受到正弦调制,仪器在不“冻结”参考状态(即CCD采样的信号不在帧存器中锁定)时,连续进行相邻两时刻散斑图的“相减”,并在监视器上得到与振型有关的实时图象。当物体达到自振频率时,将出现清楚的振型。因此,本方法可进行频率扫描,通过观察监视器的条纹场确定各阶自振频率及相应的振型,其条纹分辨率高于时间平均法,与相减法比较则可在很宽频率范围内进行频率扫描。

摘要:本文用增量理论建立了二维弹性接触问题的边界元法方程,讨论了求解接触问题过程中的一些具体做法。文中分别对盘/片组件的燕尾型与枞树型榫头与榫槽的接触应力作了数值分析。与有限元及光弹试验结果对比表明,边界元法的结果是令人满意的。

摘要:本文介绍了一种能模拟工作叶片真实载荷环境的复合疲劳试验机,并在此试验机上进行了一系列不同载荷匹配,不同频率匹配的复合疲劳试验研究。根据试验结果及理论分析,初步揭示了这种复合疲劳的一些主要特征和规律,提出相应的寿命分析方法,按照这种方法的计算结果能够较好地符合试验结果。本文提出的方法和结论可以用于航空发动机工作叶片的寿命分析。

摘要:本文用断裂力学方法对压气机和风扇转子叶片作损伤容限分析。采用20节点立体元对叶片作应力场和位移场计算,用裂纹表面位移法求解裂尖应力强度因子K_Ⅰ、K_Ⅱ及K_Ⅲ随裂纹长度a变化的关系。根据叶片材料的断裂韧性K_IC、叶片径向伸长量δ_c以及自振频率偏移量f_c值来确定转子叶片失效的准则及临界裂纹长度a_c值。利用Paris公式并考虑到高周振动应力对低周疲劳裂纹扩展的影响求得叶片的损伤容限寿命N_f。文中给出了某压气机叶片的算例。为了研究自振频率随裂纹长度变化的关系,进行了叶片振动实验

摘要:A strategy of discretization process for the 3 D disk body of complex cross section has been developed on the basis of available functions of I DEAS system.The cutting and mending techniques are employed to realize the mesh formation at the local regions of eccentric holes.In result,it is possible to solve effectively the contradiction between element distortion and over large scale of solution,and thus the 3 D analysis of the disk with eccentric hole can be completed at one time.Also in this paper an engineering optimum method is provided by adjusting the thickness of the disk so as to control the stress level at the edge of holes.

摘要:介绍了一种高速旋转条件下,盘/片(耦合)振动的新试验技术—用全息干涉术与图象消转技术结合对航空发动机盘/片组合件进行振动特性试验研究。结果表明,运用这种方法记录的动态构件的全息图与振动理论分析和频谱记录的结果相符合,可望为新机设计和航机排故提供有效的测试手段。

摘要:本文系统地研究了TC-11钛合金在室温和高温下高、低周复合疲劳行为,其中包括高低周循环应力比m、试验温度、缺口试样的预应力超载对复合疲劳寿命N_fL的影响。结果表明:复合疲劳寿命随m值的增加而明显降低,尤其是m=35时,其N_fL降低十多倍,并在m-lgN_fL曲线上,当m=10时出现一个拐点。在相同的m值和低周应力为900MPa时,当温度从室温升高到150℃时,其N_fL下降约1/3,当温度继续升高到300℃时,其N_fL接近零。此外,还提出了复合疲劳的损伤累积模型,1/N_fL=1/NL+n/N_h。

摘要:The paper presents briefly a real time rain flow method of cycle counting and its program design for the service loads of aeroengines.The concept of real time counting and its value to engineering application are also discussed.A detailed program flow chart is given which can be used in software programming of small size airborne data processing equipment.

摘要:This paper describes the blade containment tests for six sets of single model blade on a vertical breaking down tester with excess revolution.The experimental results indicate that the blade body fragment flying off impacts against the model aeroengine case time and again.The incident angle of the blade fragment against the case in the initial impact is smaller than in the later impacts,the case damage of the first impact is smaller than that of the final impact,and the impacts of the blade fragment against the case make the blade fragment crimple.In principle the experimental results of the blade fragment containment and non containment are consistent with the containment curve of single compressor blade (for use only in case of the blade body) in the Spey MK202 Stressing Standards (EGD 3) and are on the safe side.It is the preliminary conclusion that the containment curve of single compressor blade (for use only in case of the blade body) in EGD 3 can be used to predict the containment of the similar blade.

摘要:The stress and strain field and the low cycle fatigue life of a structure member with holes are calculated theoretically and investigated experimentally.The calculated results show that it is reliable to calculate the stress and strain field of a member with holes by using the shell structural elasto plastic finite element program,which has been designed and developed by the author.The satisfactory results are obtained from LCF life prediction of a member with holes by the advanced local stress and strain method.The calculation and tests show that the stress concentration of the tensile plane member is intensified and the fatigue life reduces drastically when its holes are densified in the direction perpendicular to that of tensile;the stress concentration is mitigated slightly but the fatigue life is also shortened when they are densified in the tensile direction.

摘要:Criteria for calculating low cycle fatigue strength of DZ22 superalloy under complex stress condition are considered.The fatigue life of the material under complex stresses can be predicted according to the criteria,provided its straight axial strengths and any straight axial S—N curve are available.For DZ22 as a kind of directionally solidified high temperature alloy,the low cycle fatigue comparative tests have been made between the uniaxial tension compression and tension torsion at 850℃ and show that the results of tests and calculations are in good agreement.

摘要:The local stress strain method is applied to LCF life prediction.The method and procedure for determining reliability life and flight life are provided.The influence of the variable amplitude cycle loading on the lives and effects of the fluctuation of material fatigue constants on the lives are considered.In addition the present method is compared with the EGD 3 method.

摘要:The fibre optic amplitude monitor is developed by our institute as a non contact vibration measuring system for rotator blades,in which a magnetic needle is adopted as a one per rotation sensor and a fibre optical cable as a blade passing sensor.Multiple application of the present monitor in development of new type engines demonstrates reliability and convenience in operation.It features high temperature resistance,it can work up to 350℃ and up to 400℃ in the near future.This monitor has been put in service as a main instrumentation to monitor the blade vibration in the high pressure compressor of our new type engine during its development.

摘要:针对高速多级风扇转子出口流场的特点,突出追求高频响、小尺寸、高精度、可靠性,发展了一种圆柱单孔高频压力探针。借助位移机构和高速数据采集处理系统,并在测量过程中实时标定传感器零点和灵敏度,成功地直接测出了某高速多级风扇第三级转子出口二维周期性流场。以数据的准确性和精细的分辨率,为这个级的修改设计提供了重要的真实流场依据,并证明了这种探针、测量和数据处理计算方法及测量系统简单、精细、实用和可靠。

摘要:本文详细介绍了作者发展的圆柱单孔高频压力探针测量高亚音速二维周期性流场的方法。该方法简化了压缩性影响的修正,测量时置探针于九个方位角。它已被成功地应用于单、多级高速压气机转子出口流场的测量

摘要:A two measurement at one point method with a two colour LDA(Laser Doppler Anemometer)has been used for measuring three dimensional velocity field.Various velocity distortions of the simulator have been investigated.The velocity and turbulence patterns of 90 degree torus quadrant and of torus with 20 degree slanted cut are shown.It can be seen clearly how the low velocity and large turbulence region will be caused by the flow separation from the duct lips.In order to estimate maximum instantaneous distortion,the vortex size must be measured.It is defined classically by velocity crelation and more directly than by total pressure.Some typical results are shown in a table.The vortex size is increased by the flow velocity.At 1D section the vortex size of torus with 20 degree slanted cut is about two times larger than the size of 90 degree torus quadrant.But at 3D section the former decreases and the later increases slightly.

摘要:介绍了空气喷气发动机的分析方法,以实例对于新发展的分析法和传统的能分析法做了比较。阐述了分析对于空气喷气发动机工程发展的重要意义,并强调指出空气喷气发动机中能量损失的主要部位在燃烧室。因而提高燃烧室的效率是改善发动机性能的一个重要方面。

摘要:本文根据500多台次经过0～3次翻修的同一型号发动机的台架性能,运用统计和综合分析的方法对发动机性能衰退进行了分析。提出了反映发动机整体性能的总体性能指数的概念。建立了翻修性能衰退的数学模型,并对性能衰退的发展趋势进行了预测。其结果与实际情况较为吻合,从而为发动机的使用和寿命研究提供了依据。

摘要:本文开发了一个实用的多级燃气透平S₂流面跨音正问题的计算程序,用它对一台燃气透平的改型设计进行了计算。通过计算研究了弯扭叶片在透平改型设计中应用的可能性;分析了不同的叶片弯曲方法给透平性能带来的影响;提出了对弯扭叶片的气动设计具有指导意义的意见。

摘要:本文研究轴流压气机流场周向非均匀性的动量输运和能量输运作用。作者发展了一个多级压气机的周向非均匀作用模型。模型的主要基础及初步的试验对比表明了模型的可靠性。模型的数值结果表明:周向非均匀的动量输运作用不显著,但其能量输运作用很强、具有与湍流作用相同的量级;周向非均匀的动量输运作用能否忽略不计以及周向非均匀能量输运作用与湍流作用的相对大小,都决定于压气机的几何结构、径向位置和运行工况等三个方面。

摘要:本文以一个典型的齿轮传动系统为例,讨论了辐板式结构对系统固有频率和振型等动态特性的影响,并进一步计算了当辐板柔度不同时系统的动态响应,得到了轮齿上的动载荷,分析了辐板柔度的影响和附加阻尼的效用,得出一些规律性的结论,以指导辐板结构的设计及其在减振降噪方面的应用。