Research output: Contribution to journal › Article
Effective use of metallic Z-pins for composites’ through-thickness reinforcement. / M'membe, Beene; Yasaee, Mehdi; Hallett, Stephen R.; Partridge, Ivana K.
In: Composites Science and Technology, Vol. 175, 03.05.2019, p. 77-84.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effective use of metallic Z-pins for composites’ through-thickness reinforcement
AU - M'membe, Beene
AU - Yasaee, Mehdi
AU - Hallett, Stephen R.
AU - Partridge, Ivana K.
PY - 2019/5/3
Y1 - 2019/5/3
N2 - Z-pins offer effective through-thickness reinforcement for laminated composites. Various studies have however, shown that metal Z-pins are less effective at bridging Mode I delaminations than carbon-fibre composite Z-pins, due to poor interfacial bonding with the laminate. This is exacerbated by high thermal mismatch between the metallic Z-pins and the laminate. This study investigates inserting metallic Z-pins at angles offset from the laminate normal, to improve the Mode I bridging in composites. The effects on the apparent fracture toughness under pure and mixed Mode I/II loads using single pin specimens is investigated. Results show that, unlike orthogonally inserted metal Z-pins, inclined Z-pins exhibit high energy absorption throughout the mixed mode range. Double Cantilever Beam (DCB) tests show that the inclined metal Z-pins increase the Mode I apparent fracture toughness by a factor of 2 compared to traditional carbon fibre Z-pins. In End Loaded Split (ELS) tests, the Mode II apparent fracture toughness of inclined stainless steel Z-pins, although less than their uninclined equivalent, is greater than that of carbon fibre Z-pins.
AB - Z-pins offer effective through-thickness reinforcement for laminated composites. Various studies have however, shown that metal Z-pins are less effective at bridging Mode I delaminations than carbon-fibre composite Z-pins, due to poor interfacial bonding with the laminate. This is exacerbated by high thermal mismatch between the metallic Z-pins and the laminate. This study investigates inserting metallic Z-pins at angles offset from the laminate normal, to improve the Mode I bridging in composites. The effects on the apparent fracture toughness under pure and mixed Mode I/II loads using single pin specimens is investigated. Results show that, unlike orthogonally inserted metal Z-pins, inclined Z-pins exhibit high energy absorption throughout the mixed mode range. Double Cantilever Beam (DCB) tests show that the inclined metal Z-pins increase the Mode I apparent fracture toughness by a factor of 2 compared to traditional carbon fibre Z-pins. In End Loaded Split (ELS) tests, the Mode II apparent fracture toughness of inclined stainless steel Z-pins, although less than their uninclined equivalent, is greater than that of carbon fibre Z-pins.
KW - Fracture toughness
KW - Inclined insertion
KW - Metal Z-pins
UR - http://www.scopus.com/inward/record.url?scp=85062902647&partnerID=8YFLogxK
U2 - 10.1016/j.compscitech.2019.02.024
DO - 10.1016/j.compscitech.2019.02.024
M3 - Article
VL - 175
SP - 77
EP - 84
JO - Composites Science and Technology
JF - Composites Science and Technology
SN - 0266-3538
ER -