1,720,987 research outputs found
Empirical study of the impact energy absorption enhancement of kevlar through STF impregnation
No full textImpact Monitoring of Composite Wing Using Error Outlier Assessment Based Impact Localization Algorithm and FBG Sensors
No full textLow-Velocity Impact Monitoring of Aircraft Wing Structure Using Novel Error Outlier Impact Localization Algorithm
No full textEffects of the Bonding Length on the Reflected Spectra and Strain Measurement of the Surface Bonded Fiber Bragg Grating Sensor
No full textInvestigation of Multi-layer Embedded FBG Sensor Response under Simulated LEO Environment Exposure
No full textInvestigation of LEO environment exposure monitoring potential using embedded FBG sensors
No full textComposite materials provide many advantages over conventional materials including metals, especially for space applications. However, composites have failure modes that are complex and difficult to identify, and various cracks and delamination are predominantly difficult to detect visually. In this regard, an effective method of monitoring the integrity of composite materials and structures exposed to hazardous space environments is necessary to ensure the long-term reliability of composite materials in aerospace applications. FBG sensors are advantageous for space applications due to their immunity to various environments. In this study, FBG sensors were used to investigate LEO environment exposure monitoring of CFRP
Signal characteristics of the surface bonded fiber Bragg grating sensors by bonding length under different load types
No full textThe surface-bonding method of the fiber Bragg grating(FBG) sensor is easier to handle than embedding method. However surface bonded FBG sensors have the limitation of the signal characteristics being affected by the bonding layer. In this study, the effects of the bonding length on the surface installed FBG sensor signal characteristics under various load types were empirically investigated. To evaluate the stability of the signal characteristics of the FBG sensors, the strain transfer rate and the multiple peaks ratio of the reflected spectrum were calculated and compared. From the experimental results, the strain transfer ratio and multiple peaks ratio varied because of the different strain gradients formed depending on the applied load type. Therefore, it was found that the effective bonding length for respective load types need to be determined to get a stable signal from the surface bonded FBG sensors
Low velocity impact monitoring of composite wing structure under simulated wing loading condition using fiber Bragg grating sensors
No full textA low velocity impact onto a composite structure can result in the occurrence of barely visible impact damage (BVID), which is difficult to detect. Therefore, the low velocity impact monitoring of composite structures is highly desirable for impact detection and localization. In this paper, low velocity impacts on a composite wing under a simulated wing loading condition were monitored using six multiplexed fiber Bragg grating (FBG) sensors and localized using error outlier based impact localization algorithm. The impact response signals from the FBG sensors were sampled at a rate of 100 kHz using high-speed interrogator. The impacts were localized with an average error of 18.4 mm
Numerical Modeling of High Velocity Impact of STF Impregnated Kevlar Fabric with a Focus on Friction
No full textHypervelocity impact of space debris on multiple composite bumpers: Experiments & simulations using LS-DYNA
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