Dynamic Deformation Measurement of Fan Blades

Experimental Background

The deformation and failure mechanisms of materials under extreme conditions (e.g., high-speed rotation, impact, explosion) are critical research topics in aerospace, automotive, and civil engineering. Traditional contact methods (e.g., strain gauges) are constrained by single-point measurements and susceptibility to interference, rendering them inadequate for full-field strain analysis and high-temporal-resolution acquisition in dynamic scenarios.

As a non-contact optical technique, Digital Image Correlation (DIC) tracks surface speckle displacement fields to accurately compute full-field strain distributions. When coupled with high-speed cameras, DIC captures dynamic deformation processes at millisecond or microsecond scales. This experiment focuses on fan blades—components subjected to complex centrifugal and aerodynamic loads during high-speed rotation. Their strain distribution and structural reliability are intrinsically linked, making them a typical scenario for validating the engineering practicality of DIC technology.

  Experimental Methodology

his study employed a high-speed imaging system and Digital Image Correlation (DIC) to establish a comprehensive experimental framework, from hardware setup to data acquisition.

01 Hardware Configuration

• High-Speed Cameras: Two SinceVision SH3-108 cameras were utilized. At a full-frame resolution of 1280×1024, they achieved a frame rate of 8000 fps, enabling clear capture of high-speed fan blade dynamics.

• Setup & Synchronization: The two cameras were mounted at an optimal angle in front of the fan, ensuring the region of interest remained stably within the field of view for continuous, clear dynamic image acquisition.

02 Sample Preparation

• Speckle Pattern: A random speckle pattern was applied to the blade surface to provide the texture features required for DIC software analysis.

• Region of Interest (ROI): Small sub-regions ("Stage Rectangles 0-5") were defined at the blade root, mid-span, and tip. This configuration covers critical stress zones from root to tip, facilitating the analysis of strain gradients.

Experimental Results and Analysis

This experiment fully demonstrates the advantages of the SinceVision SH3-108 high-speed camera and DIC technology in dynamic deformation measurement:

• Non-contact Full-field Measurement: Overcoming the single-point limitation of traditional contact methods, it enables visualized measurement of the full strain field on the blade surface, providing comprehensive data support for structural optimization.

• High Spatiotemporal Resolution: With a frame rate of 8000 fps and a measurement accuracy of 50 micro-strains, it precisely captures instantaneous deformation under high-speed rotation, meeting the measurement demands of extreme operating conditions.