UAV Modal Testing for Vibration Analysis & Structural Optimization
Project title: UAV Modal Testing for Vibration Analysis & Structural Optimization
A new reconnaissance-strike UAV exhibited abnormal vibrations during high-speed dive maneuvers, causing blurring in its electro-optical pod imagery. A research institute utilized the DE-944 dynamic testing system to conduct modal testing on critical components, identifying vibration sources and guiding structural optimization.
1. Innovative Test System Configuration
Multi-Excitation Coordination System:
Main Exciter: TEN-M200 (200N) for global modal excitation
Auxiliary Exciter: Miniature electromagnetic (20N) for local structural analysis
DE-944 System Integration: Achieved multi-channel phase synchronization (<0.1° error)
Intelligent Sensor Network:
Deployed 32 triaxial accelerometers (including 4 high-temperature sensors near the engine bay)
Utilized wireless sensing nodes for rotating components (e.g., fuel pump)
2. Key Technological Breakthroughs
(1) Composite Excitation Technology
Developed "Stepped Sweep" algorithm:
Baseline sweep: 0.1-500Hz @ 2Hz/s
Critical frequency band: 80-150Hz @ 0.2Hz/s (engine operating range)
Random excitation overlay: Enhanced nonlinear feature identification
(2) Environmental Noise Suppression
Applied adaptive filtering:
Real-time separation of engine background noise (SNR improved to 45dB)
Developed deep learning-based anomaly detection (98.7% accuracy)
3. Engineering Issue Diagnosis
Identified Critical Abnormal Modes:
| Location | Frequency | Damping Ratio | Root Cause |
|---|---|---|---|
| Right Wing Pylon | 118Hz | 0.3% | Insufficient actuator mounting stiffness |
| EO Pod Bracket | 87Hz | 1.2% | Composite material delamination |
Vibration Transmission Path Analysis:
4. Structural Optimization Solutions
(1) Dynamic Performance Improvements
Pylon Stiffness Enhancement: Added titanium alloy bushings (40% stiffness increase)
EO Pod Vibration Isolation: Installed active dampers (90% vibration reduction)
(2) Process Improvements
Implemented laser-ultrasonic inspection for composite curing quality
Optimized bolt fastening process (±5% preload control accuracy)
5. Validation Results
Flight Test Data Comparison:
| Metric | Pre-Optimization | Post-Optimization |
|---|---|---|
| Image Stability | 2.3 pixels | 0.5 pixels |
| Structural Fatigue Life | 800h | 2500h |
| Maximum Maneuver G-Load | 5.2G | 6.8G |
Technology Extension Value
Established "UAV Modal Testing Standards" (Q/AVIC-2023)
Applied to new high-speed UAV development, cutting testing time by 40%
Developed real-time vibration monitoring system for in-flight early warning
