程控振动疲劳试验系统

航空叶片的疲劳断裂是发动机的常见故障之一,为了研究其失效机理,国内外都采用恒定应力疲劳寿命试验。叶片的疲劳载荷主要以数值分析法来给出,或者按台架试车中实测到的最大振动应力作为载荷,试验做到各组样品均有一定数量的产品发生失效为止,用它来估计产品的各种可靠性特征。传统采用的试验方案是人工操作开环控制激振。

A COMPUTER-CONTROLLED VIBRATORY FATIGUE TEST RIG WITH PROGRAMMED LOADING FOR BLADING

In order to improve the accuracy in experimental prediction of service life of axial-flow compressor blade,it is necessary to simulate random field loads in the laboratory. Based on recorded flight spectrum loading, a microcomputer system for data processing and counting was successfully utilized to derive a mathematical model for a steppedload spectrum and software programming. For simulation by programmed step loading, a computer-controlled closed cycle servo-electrical test righas been newly devised. This paper describes briefly its design and technical features. On this rig, a fatigue life distribution of certain compressor blading was automatically tested under its simulated flight block load spectrum. This advanced technique for inspection of the fatigue life and quality in blade production may be employed by blade manufacturing factory to enhance the flight reliability.