风扇轴高/低周复合疲劳试验方法研究及设计

为了实现风扇轴在轴向力、主扭矩、振动扭矩和旋转弯矩载荷联合作用下，真实模拟试验件边界环境，且不引入额外载荷的要求下进行高/低周复合疲劳（HCF/LCF）试验.采用机械设计技术、液压技术、计算机技术和数据采集技术，提出了轴向力、主扭矩、振动扭矩和旋转弯矩载荷的加载方法，建立了4种载荷的控制系统和标定系统，并设计了大涵道比涡扇发动机风扇轴试验器.试验器利用计算机测控系统，通过信号提取、电液伺服阀和机械系统可同时实现轴向力、主扭矩、振动扭矩和旋转弯矩载荷的协调加载.结果表明:试验器高周载荷加载频率可达到9Hz，低周疲劳载荷加载精度优于±0.12%，振动扭矩载荷加载精度优于±2%，92.75%的旋转弯矩加载数据精度优于±5%，旋转弯矩误差范围为±9%.试验器具有良好的重复性和线性度. 

Investigation and design for HCF/LCF complex fatigue experiment method of fan shaft

In order to accomplish the fan shaft's high-cycle fatigue/low-cycle fatigue (HCF/LCF) complex fatigue experiment under combined loading of axial force,principal torsion,vibration torsion and rotating moment,the sample's boundary conditions was simulated truly without inducing other extra loading.A loading method under these conditions was proposed based on mechanism design skills,hydraulics kills and computer data acquisition technology,meanwhile four kinds of loading control and calibrated system were established,and a fan shaft fatigue experiment device of high bypass ratio turbofan engine was designed.Making use of computer measurement and control systems,this experiment device can achieve the harmonious loading of axial force,principal torsion,vibration torsion and rotating moment by signal extraction,electro-hydraulic servo valve and mechanism system.Result showed that the high circle loading frequency could reach to 9 Hz,the precision of low circle fatigue,vibration torsion and 92.75％ the rotating moment to be loaded was superior to than ±0.12％,±2％ and ±5％,respectively,the maximum error of rotating moment didn't exceed ±9％.This experiment device has well repeatability and linearity.