PSI - Issue 14

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 14 (2019) 354–361 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000

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XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Thermo-mechanical modeling of a high pressure turbine blade of an airplane gas turbine engine P. Brandão a , V. Infante b , A.M. Deus c * a Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal b IDMEC, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal c CeFEMA, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal Abstract During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation company, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2nd International Conference on Structural Integrity and Exhibition 2018 Mixed-Mode Cohesive Law Estimation of Composite Joints Made of Toughened Epoxy Adhesive Mohd Tauheed, Naresh V. Datla * Department of Mechanical Engineering, IIT Delhi, Hauz Khas, New Delhi, India 110016 Abstract Joining composites using adhesive bonding is attractive because they reduce the weight of structure and allow to join complex shapes. These benefits encourage use of composite adhesive joints in aerospace and automotive industries. However, composite adhesive joints are seldom used for primary structures because of our limited understanding of their failure, especially under mixed-mode loads. Predicting the f ilure of compo ite joints is challenging b cause th failure can ccur cohesive in adhesive, interfacial between adhesive/adherend, or within the composite adherend. Moreover, these failures depend on the specimen geometry, loading conditions, surface treatments, and environmental conditions. Recent studies showed that cohesive zone approach can be used to reliably predict failure, but most of these studies are limited to failure under mode I loads and further for brittle epoxy adhesives. In this study, traction-separation laws (TSL) were extracted for composite joints made of toughened epoxy adhesive through fracture tests and by applying the digital image correlation (DIC) technique. These TSLs were used for strength prediction of composite joints subjected to mixed-mode loading. Composite adhesive joints were made of carbon fiber/epoxy composite adherend and Araldite 2015 epoxy adhesive. Mode I and mode II fracture testing were conducted using the double cantilever beam and end notch flexural specimens, respectively. From these fracture tests, TSLs were extracted by using a direct method based on the DIC technique. These TSLs were used in a finite element (FE) model of a lap shear joint model in ANSYS to predict the failure strength. This FE predicted failure strength reasonably agreed with the experimentally determi ed failure strength of the toughened adhesive joint. © 2018 The Au hors. Published by Elsevier B.V. This is an open access articl under the CC BY-NC-ND icense (https://crea ivecommons org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2nd International Conference on Structural Integrity and Exhibition 2018 Mixed-Mode Cohesive Law Estimation of Composite Joints Made of Toughened Epoxy Adhesive Mohd Tauheed, Naresh V. Datla * Department of Mechanical Engineering, IIT Delhi, Hauz Khas, New Delhi, India 110016 Abstract Joining composites u ing adhesive bonding is attractive because they r duce the weight of structure and allow to join complex shapes. These benefits encourage use of composite adhesive joints in aerospace and automotive industries. However, composite adh sive joints are s l om used for primary structur s because of our limited un rstand ng of their failure, especially und r mixed-mode loads. Predicting t failure of composite j ints is challengi g because the failure can occur cohesive in adhesive, interfacial between adhes ve/adherend, or within the composite adherend. M reover, these fa lures depend on the p cimen geometry, loading conditions, su face treatments, and environmental conditions. Recent st dies sh wed that cohesive zone approach can be used to reliably pre ict f ilure, but most of the e studies a limited to ailure under mode I loads and further for brittle epoxy adhesives. In this study, traction-separation laws (TSL) were x racted for composite joints made of to ghened epoxy adhesive through fracture tests and by applying the digital image correlation (DIC) technique. These TSLs w re used f r str ngth prediction of composite joints subjected to mixed-mode loading. Composite adhesiv joints were made of carbon fiber/epoxy composite adhere a Araldite 2015 e oxy adhesive. Mode I and mode II fracture testing were conducted using the double cantil ver be m and end notch flexural specimens, resp ctively. From thes fracture tests, TSLs were extracted by using a direct meth d based on the DIC echnique. These TSLs were used in a finit element (FE) model of a la shear joint model n ANSYS to predict the failure strengt . This FE predicted failure stre gth reasonably agreed with the experimentally det rmined failure strength of the tough n d adhesive joint. © 2018 The Authors. Published by Els v er B.V. This is a open access article und r the CC BY-NC-ND lic nse (https://creat vecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under respon ibility of Peer-review under responsibility of the SICE 2018 organizers. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywo ds: Cohesive zon m delling; mixed-mode; digital image corr lation; toughened epoxy Keywords: Cohesive zone modelling; mixed-mode; digital image correlation; toughened epoxy

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.:+91-11-2659-6071 E-mail address: datla@mech.iitd.ac.in * Corresponding au hor. T l.:+91-11-2659-6071 E-mail address: datla@mech.iitd.ac.in

2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is a open access article und r the CC BY-NC-ND lic nse (https://creat vecommons.org/licenses/by- c-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 10.1016/j.prostr.2019.05.044