Development of an FBG Sensor Array for Multi-Impact Source Localization on CFRP Structures.

Area of Science:

• Materials Science
• Mechanical Engineering
• Sensor Technology

Background:

• Composite materials like CFRP are susceptible to impact damage.
• Effective impact detection is crucial for structural integrity and safety.
• Existing methods may lack precision in locating multiple impact events.

Purpose of the Study:

• To develop and validate an impact detection system for carbon fiber-reinforced polymer (CFRP) plates.
• To accurately determine the location and number of low-velocity impacts.
• To assess the system's performance using a fiber Bragg grating (FBG) sensor array and the MUSIC algorithm.

Main Methods:

• Utilized a linear array of seven FBG sensors to capture ultrasonic signals from impacts.
• Employed edge-filter method for signal demodulation and Shannon wavelet transform for signal extraction.
• Applied the Gerschgorin disc theorem to estimate the number of impacts.
• Implemented the MUSIC algorithm for precise multi-impact localization.

Main Results:

• The developed system successfully detected and located multiple impacts on a CFRP plate.
• Localization errors were quantified, with a maximum error of 9.2 mm and an average error of 7.4 mm.
• The system demonstrated effectiveness in identifying both the number and coordinates of impacts.

Conclusions:

• The proposed FBG sensor array and MUSIC algorithm system offers a viable solution for impact detection in CFRP structures.
• The system achieves good localization accuracy for low-velocity impacts.
• This technology can enhance structural health monitoring and damage assessment capabilities.