OS08-4-3 Electrical Resistance Change in the Moisturized CFRP Laminates under the Freezing Point

2011 ◽  
Vol 2011.10 (0) ◽  
pp. _OS08-4-3-
Author(s):  
Keiji Ogi
Keyword(s):  
Electrical Resistance ◽  
Freezing Point ◽  
Resistance Change ◽  
Cfrp Laminates ◽  
Electrical Resistance Change

PS31 Electrical resistance change of CFRP laminates under cyclic loading

2012 ◽  
Vol 2012 (0) ◽  
pp. _PS31-1_-_PS31-3_
Author(s):  
Daichi HARUYAMA ◽  
Akira TODOROKI ◽  
Yoshihiro MIZUTANI ◽  
Yoshiro SUZUKI
Keyword(s):  
Cyclic Loading ◽  
Electrical Resistance ◽  
Resistance Change ◽  
Cfrp Laminates ◽  
Electrical Resistance Change

Effect of Dent on Self-Sensing Method of CFRP

2010 ◽  
Vol 123-125 ◽  
pp. 963-966 ◽  
Author(s):  
Akira Todoroki ◽  
Roysuke Matsuzaki ◽  
Yusuke Samejima ◽  
Yoshiyasu Hirano
Keyword(s):  
Residual Stress ◽  
Electrical Resistance ◽  
Stress Relief ◽  
Resistance Change ◽  
Delamination Crack ◽  
Cfrp Laminates ◽  
Crack Location ◽  
Indentation Tests ◽  
Resistance Decrease ◽  
Electrical Resistance Change

Authors’ group has been done researches on the damage monitoring of the laminated Carbon Fiber Reinforced Plastic (CFRP) using the electrical resistance change method. The method adopts reinforcement carbon fibers as sensors, and it is called self-sensing method. Using thin CFRP laminates, delamination crack location and dimension are identified with the electrical resistance change method. However, the electrical resistance decreases when a delamination crack is made in a thick CFRP beam. The present paper experimentally investigates the effect of the dent for the measurements of electrical resistance change. Indentation tests are performed for the thick CFRP plates. The effect of the dent is calculated compared with the effect of piezoresistivity caused by the residual stress relief. As a result, the effect of the dent is larger than the effect of the residual stress relief for the thick CFRP. For the thick CFRP, dents cause the significant reduction of the electrical resistance in the thickness direction, and that causes electrical resistance decrease.

Matrix Crack Detection of CFRP Laminates in Cryogenic Temperature Using Electrical Resistance Change Method

2006 ◽  
Vol 321-323 ◽  
pp. 873-876 ◽  
Author(s):  
Akira Todoroki ◽  
Kazuomi Omagari ◽  
Masahito Ueda
Keyword(s):  
Electrical Resistance ◽  
Cryogenic Temperature ◽  
Matrix Crack ◽  
Fuel Tank ◽  
Matrix Cracking ◽  
Resistance Change ◽  
Cfrp Laminates ◽  
Resistance Increase ◽  
Matrix Cracks ◽  
Electrical Resistance Change

For a cryogenic fuel tank of a next generation rocket, a Carbon Fiber Reinforced Plastic (CFRP) laminated composite tank is one of the key technologies. For the fuel tank made from the laminated composites, matrix cracks are significant problems that cause leak of the fuel. In the present paper, electrical resistance change method is adopted to monitor the matrix cracking of the CFRP laminate. Previous studies show that tension load in fiber direction causes electrical resistance increase due to the piezoresistivity of the carbon fibers, and fiber breakages also cause the electrical resistance increase of the CFRP laminates. In order to distinguish the electrical resistance changes due to matrix cracking from those due to the piezoresistivity and the fiber breakages, residual electrical resistance change under the complete unloading condition is employed in the present study. Experimental investigations were performed using cross-ply laminates in cryogenic temperature. As a result, it can be revealed that the residual electrical resistance change is a useful indicator for matrix crack monitoring of the cross-ply CFRP laminates.

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