TY - JOUR
T1 - Fracture analysis of Kevlar-49/epoxy and e-glass/epoxy doublers for reinforcement of cracked aluminum plates
AU - Kasavajhala, Ananth Ram Mahanth
AU - Gu, Linxia
N1 - Funding Information:
The supports of NASA Nebraska Space Grant and National Science Foundation under Grant No. 0811250 are gratefully acknowledged.
PY - 2011/7
Y1 - 2011/7
N2 - Adhesively bonded composite patch repair is efficient means to regain load carrying capacity, alleviate the crack growth, and improve the service life of the damaged structure. In this paper, three dimensional finite element models are developed to examine the fracture behavior of a single edge V-notched Aluminum plate repaired with Kevlar-49/epoxy or e-glass/epoxy pre-preg patches on both sides. Contour integral method was used for evaluating the stress intensity factor (SIF), an indicator of the crack stability. The load transfer mechanisms, stress distribution, damage variable (D), and crack mouth opening displacement (CMOD), were also presented to estimate the effectiveness of composite patch repair. The influence of the patch material, crack length and the adhesive thickness has been investigated. Results have shown that the crack induced damage increased nonlinearly with a larger crack size. With the composite patch repairs, SIF is reduced to 1/7-1/10 of that of the bare plate and CMOD decreased by 79%. The damage variable is reduced significantly and the load capacity is increased. A thinner adhesive layer results in a higher percentage of load shared by the composite patch.
AB - Adhesively bonded composite patch repair is efficient means to regain load carrying capacity, alleviate the crack growth, and improve the service life of the damaged structure. In this paper, three dimensional finite element models are developed to examine the fracture behavior of a single edge V-notched Aluminum plate repaired with Kevlar-49/epoxy or e-glass/epoxy pre-preg patches on both sides. Contour integral method was used for evaluating the stress intensity factor (SIF), an indicator of the crack stability. The load transfer mechanisms, stress distribution, damage variable (D), and crack mouth opening displacement (CMOD), were also presented to estimate the effectiveness of composite patch repair. The influence of the patch material, crack length and the adhesive thickness has been investigated. Results have shown that the crack induced damage increased nonlinearly with a larger crack size. With the composite patch repairs, SIF is reduced to 1/7-1/10 of that of the bare plate and CMOD decreased by 79%. The damage variable is reduced significantly and the load capacity is increased. A thinner adhesive layer results in a higher percentage of load shared by the composite patch.
KW - A. Structural composites
KW - C. Finite element analysis (FEA)
KW - C. Stress concentrations
KW - C. Stress transfer
KW - Damage variable
UR - http://www.scopus.com/inward/record.url?scp=80052291476&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80052291476&partnerID=8YFLogxK
U2 - 10.1016/j.compstruct.2011.02.012
DO - 10.1016/j.compstruct.2011.02.012
M3 - Article
AN - SCOPUS:80052291476
SN - 0263-8223
VL - 93
SP - 2090
EP - 2095
JO - Composite Structures
JF - Composite Structures
IS - 8
ER -