PSI - Issue 18

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 18 (2019) 353–367

25th International Conference on Fracture and Structural Integrity The effect of residual stress induced by manufacturing on strength on free edge of carbon-epoxy composite with [0 0 /90 0 ] n layup D.A. Bondarchuk a , B.N. Fedulov a,b , A.N. Fedorenko a,b * a Lomonosov Moscow State University, GSP-1, Leninskie Gory,Moscow,119991,Russian Federation Skolkovo Institute of Science and Technology,Bolshoy Boulevard 30,bld.1,Moscow,121205,Russian Federation 25th International Conference on Fracture and Structural Integrity The effect of residual stress induced by manufacturing on strength on free edge of carbon-epoxy composite with [0 0 /90 0 ] n layup D.A. Bondarchuk a , B.N. Fedulov a,b , A.N. Fedorenko a,b * a L monosov Moscow St te University, GSP-1, Leninskie Gory,Moscow,119991,Russian Federation Skolkovo Institute of Science and Technology,Bolshoy Boulevard 30,bld.1,Moscow,121205,Russian Federation Last decades, increased attention is paid to well-known stress concentration phenomenon rich in research tradition is so-called free-edge effect. Despite the fact that the problem is not new there is no well-known approaches in engineering practice to take residual stress and free edge effects simultaneously for fracture analysis. The presence of residual stresses combined with mechanical loads can cause several defects in composite laminates and structures such as fiber and tow misalignment, transverse cracking (known as micro-cracking) delamination and warpage. In the present study, the effect of free edge on residual stresses inherited during manufacturing of thermoset multilayered composites was investigated. Last decades, incr ased attention is paid to w ll-known stress concentration phenomenon rich i research tradition is s -called free-edge effect. Despite the fact that the pr blem is not new there is no well-known approaches in engineering practice to take residual stress and fre edge eff ts simultaneously for fracture analysis. The presenc of residual stresses combined with me hanical l ads can cause several defects in c mposite laminates and structures such as fiber and tow misalignment, transverse cracking (known as micro-cracking) delamination and warpage. In the present study, the effect of free edge on residual stresses inherited during manufacturing of thermoset multilayered composites was investigated. - predict the value of r sidual stresses in composite sample during the polymerization process; - determine the change in residual stress states of p lymerized composite sample after straight line cut into two parts. Compare the stress distribution in a sample after cut without consid ring th influence of residual stresses - determine the cha ge in stress distributi n near free edge after te sile loading after cut (along the notch line). Compare with the stress distribution in sample after tensile loading along the notch line without considering residual stresses. - compare damage distribution near the free edge with the presence of manufacturing residual stresses and without one in case of uniaxial loading of composite material. The purpose of this study can be formulated by following steps: The purpose of this study can be formulated by following steps: - predict the value of residual stresses in composite sample during the polymerization process; - determine the change in residual stress states of polymerized composite sample after straight line cut into two parts. Compare the stress distribution in a sample after cut without considering the influence of residual stresses - determine the change in stress distribution near free edge after tensile loading after cut (along the notch line). Compare with the stress distribution in sample after tensile loading along the notch line without considering residual stresses. - compare damage distribution near the free edge with the presence of manufacturing residual stresses and without one in case of uniaxial loading of composite material. Abstract Abstract

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 201 9 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 201 9 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: composite material; residual stress; stress relaxation; defects; free edge Keywords: composite material; residual stress; stress relaxation; defects; free edge

* Corresponding author. Tel.: +7-915-240-52-53. E-mail address: bondarchuk.da@mail.ru * Corresponding author. Tel.: +7-915-240-52-53. E-mail address: bondarchuk.da@mail.ru

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo.

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2019.08.175