Damage Assessment in Composites using Fiber Bragg Grating Sensors

COMPOSITES;DAMAGE ASSESSMENT;FINITE ELEMENT;BRAGG GRATINGS

Prabhugoud, Mohanraj ; Dr. KARA J. PETERS, Committee Chair,Dr. MOHAMMED A. ZIKRY, Committee Member,Dr. TASNIM HASSAN, Committee Member,Dr. ERIC C. KLANG, Committee Member,Prabhugoud, Mohanraj ; Dr. KARA J. PETERS ; Committee Chair ; Dr. MOHAMMED A. ZIKRY ; Committee Member ; Dr. TASNIM HASSAN ; Committee Member ; Dr. ERIC C. KLANG ; Committee Member

University:North Carolina State University

关键词: COMPOSITES;    DAMAGE ASSESSMENT;    FINITE ELEMENT;    BRAGG GRATINGS;   

Others  :  https://repository.lib.ncsu.edu/bitstream/handle/1840.16/3930/etd.pdf?sequence=1&isAllowed=y

美国|英语

来源: null

【 摘 要 】

This dissertation develops a methodology to assess damage in composites using fiber Bragg grating (FBG) strain sensors. First, a strain-transfer model using the finite element (FE) method is developed to simulate the response of an embedded FBG to the applied loading. This FE model is also able to calculate birefringence in the FBG due to applied transverse loads. The model is validated considering the two-dimensional problem of diametrical compression of polarization-maintaining fibers. A modified T-matrix model is then formulated to simulate the response of an embedded FBG due to an applied axial strain field. The response of FBGs surface mounted on PMMA and two-dimensional woven composites subjected to multiple low velocity impacts is experimentally investigated. The complex spectral response is related to the residual strains after impact in the PMMA specimens and the surface strain to failure in the two-dimensional woven composites. The feasibility of using FBGs to measure internal strain in woven composites during damage progression is finally considered.