PSI- Issue 9

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 9 (2018) 229 – 234 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 9 (2018) 229 – 234 Available online at www.sciencedirect.com Procedia Structural Integrity 9 (2018) 229–234

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

IGF Workshop “ Fracture and Structural Integrity ” Energy damage approaches of artificially notched and aged thermoplastic pipes Fatima Majid a , * , Mohammed Ezzahi a , Mohamed Elghorba a a Laboratoire de contrôle et de caractérisation des matériaux et des structures, Génie Mécanique, Ecole Nationale Supérieure d’ Electricité et de Mécanique, Université Hassan II, Km7, route ELJADIDA, 20000, Casablanca, MAROC. Abstract In this paper, the energy parameter has been chosen for the damage modeling and specifically for the modification of the non-linear models based on the static damage. It has been determined through burst tests and tensile test of newly produced and aged HDPE pipes respectively. In fact, the energy parameter have been defined through different methods undertaking the burst and tensile behavior in order to build the energy damage models. Afterwards, the results of the modified static damage has shown good correlations between the burst models and the tensile ones. These findings have proved that the energy is a reliable and a representative parameter for the HDPE material behavior exposed to either artificial or natural degradations. Indeed, both of the developed models have shown that the degradations lead to a significant decrease in the released energy causing the acceleration of the damage proportionally to the damage degree and the harmfulness of the noticeable degradations. IGF Workshop “ Fracture and Structural Integrity ” Energy damage approaches of artificially notched and aged thermoplastic pipes Fatima Majid a , * , Mohammed Ezzahi a , Mohamed Elghorba a a Laboratoire de contrôle et de caractérisat on des m tériaux et des str ctures, Génie Mécanique, Ecole Nationale Supérieure d’ Electricité et de Mécanique, Université Hassan II, Km7, route ELJADIDA, 20000, Casablanca, MAROC. Abstract In this paper, the energy parameter has been chosen for the damage modeling and specifically for the modification of the non-linear mo els based on the static damage. It has been determined through burst tests and tensile test of newly produced and aged HDPE pipes respectively. I fact, the energy parameter have been defined through different methods undertaking the burst and tensile behavior in order to build the energy da age models. Afterwards, the results of the modified static damage has shown good correlations between the burst models and the tensile ones. These findings have proved that the energy is a reliable and a representative parameter for the HDPE material behavior exposed to either artificial or natural degradations. I deed, both of the developed models have shown that the degradations lead to a si nificant decrease in the released energy causing the acceleration of the damage proportionally to the damage degree and the harmfulness of the noticeable degradations.

© 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: Energy appraoch; Aamage modeling; Agieng effect; Thermoplastic pipes. Keywords: Energy appraoch; Aamage modeling; Agieng effect; Thermoplastic pipes.

1. Introduction HDPE pipes are generally exposed to many defects during their usage. Many studies in the literature have studied the linear and nonlinear concepts related to damage assessment of these materials. Indeed, many parameters can be 1. Introduction HDPE pipes are generally exposed to many defects during their usage. Many studies in the literature have studied the linear and nonlinear concepts related to damage assessment of these materials. Indeed, many parameters can be

* Corresponding author. Tel.: +212 663 49 90 78; E-mail address: majidfatima9@gmail.com * Correspon ing author. Tel.: +212 663 49 90 78; E-mail address: majidfatima9@gmail.com

2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2018.06.041 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 2452-3216 © 2018 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo.