Large strain detection of SRM composite shell based on fiber Bragg grating sensor

Abstract

There may be more than 2% strain of carbon fiber composite material on solid rocket motor (SRM) in some extreme cases. A surface-bonded silica fiber Bragg grating (FBG) strain sensor coated by polymer is designed to detect the large strain of composite material. The strain transfer relation of the FBG large strain sensor is deduced, and the strain transfer mechanism is verified by finite element simulation. To calibrate the sensors, the tensile test is done by using the carbon fiber composite plate specimen attached to the designed strain sensor. The results show that the designed sensor can detect the strain more than 3%, the strain sensitivity is 0.0762 pm/με, the resolution is 13.13με, and the fitting degree of the wavelength-strain curve fitting function is 0.9988. The accuracy and linearity of the sensor can meet the engineering requirements.

Highly stretchable hybrid silica/polymer optical fiber sensors for large-strain and high-temperature application

“…Huang et al reported a long-period fiber grating (LPFG) optic sensor packaged with a hybrid mechanism of elastic attachment and gauge length change in a high-temperature environment. The maximum strain was as high as 15200 με (~1.5%) [9]. Zhang et al proposed an FBG sensor packaged by polydimethylsiloxane (PDMS) to monitor 2% strain of carbon fiber composite material on solid rocket motor [10].…”

Mechanical and piezo-resistance behavior of CNTs/Epoxy resin composite for structural health monitoring

“…However, many diagnostic technologies are still complicated [1]. For example, fiber Bragg grating sensor (FBG) is sensitive to strain and temperature, which needs to be pasted on the surface (or embedded inside the material) of the measuring material or structure [2,3]. For signal detection and fault diagnosis, applications like rail fastener gasket, hydraulic device seals, and aircraft composite structural parts, were inconvenient to disassemble from the product and re-install a certain amount of sensors for signal acquisition.…”