PSI - Issue 24

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ScienceDirect

Procedia Structural Integrity 24 (2019) 526–540 Structural Integrity Procedia 00 (2019) 000–000 Structural Integrity Procedia 00 (2019) 000–000

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

© 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the AIAS2019 organizers Abstract The certification process of an aeronautical structural component is developed on a complex and articulated path. In particular, the certification regulations dictate requirements to be demonstrated to which certification of compliance is given by means of the evidence produced with specific qualification tests. This long and costly test activity lead, in some cases, to the sacrifice of test articles, interfering, if the results are unexpected, with the design process. In this scenario, the simulation of the test thus becomes a necessary prediction tool, which must be as accurate and predictive as possible. The test case reported here is a structure designed to equip a fleet of military helicopters with di ff erent observation devices. The qualification tests required by MIL-STD 810-G concerning durability and dynamic response were simulated. In order to increase the predictive power of the simulations, an intense experimental modal analysis campaign was carried out on which the numerical model was calibrated. The prototype of the structure was then subjected to an experimental flight activity, aimed at evaluating its functionality, and based on the data collected, to validate its numerical representation. The comparison between the simulated test and the exposure to the operating environment, have led to a critical re-reading of the standards, which involves all the test activity transversely, from the summary of the spectra to the the qualification tests compression. A case study based on the prediction of the qualification test that becomes the starting point for a critical analysis on the acceptability of the numerically produced evidences. c 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) er-review line: Peer-review und r responsibility of the AIAS2019 organizers. Keywords: Random Fatigue; Structural Dynamics; FEA; Damage Model; Sine on Random, Rainflow Counting AIAS 2019 International Conference on Stress Analysis Virtual qualification of aircraft parts: test simulation or acceptable evidence? Filippo Cianetti a , Giulia Morettini a , Massimiliano Palmieri a , Guido Zucca a,b, ∗ a Perugia University, Engineering Department,Via G. Duranti 67, 06125 Perugia b Italian Air Force, Flight Test Center, Technology Materials for Aeronautics and Space Department, M. de Bernardi AFB, via di Pratica di Mare, 00040 Pomezia (RM) Italy Abstract The certification process of an aeronautical structural component is developed on a complex and articulated path. In particular, the certification regulations dictate requirements to be demonstrated to which certification of compliance is given by means of the evidence produced with specific qualification tests. This long and costly test activity lead, in some cases, to the sacrifice of test articles, interfering, if the results are unexpected, with the design process. In this scenario, the simulation of the test thus becomes a necessary prediction tool, which must be as accurate and predictive as possible. The test case reported here is a structure designed to equip a fleet of military helicopters with di ff erent observation devices. The qualification tests required by MIL-STD 810-G concerning durability and dynamic response were simulated. In order to increase the predictive power of the simulations, an intense experimental modal analysis campaign was carried out on which the numerical model was calibrated. The prototype of the structure was then subjected to an experimental flight activity, aimed at evaluating its functionality, and based on the data collected, to validate its numerical representation. The comparison between the simulated test and the exposure to the operating environment, have led to a critical re-reading of the standards, which involves all the test activity transversely, from the summary of the spectra to the the qualification tests compression. A case study based on the prediction of the qualification test that becomes the starting point for a critical analysis on the acceptability of the numerically produced evidences. c 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review line: Peer-review under responsibility of the AIAS2019 organizers. Keywords: Random Fatigue; Structural Dynamics; FEA; Damage Model; Sine on Random, Rainflow Counting AIAS 2019 International Conference on Stress Analysis Virtual qualification of aircraft parts: test simulation or acceptable evidence? Filippo Cianetti a , Giulia Morettini a , Massimiliano Palmieri a , Guido Zucca a,b, ∗ a Perugia University, Engineering Department,Via G. Duranti 67, 06125 Perugia b Italian Air Force, Flight Test Center, Technology Materials for Aeronautics and Space Department, M. de Bernardi AFB, via di Pratica di Mare, 00040 Pomezia (RM) Italy

1. Introduction 1. Introduction

In a century of vibrant growth, aviation has established itself under the pressure of very di ff erent paradigms Moore (2013). If in the first fifty years of intense innovation, the focus was on a rapid and absolute technical improvement of the vehicle, in a second period, the evolutionary path has been oriented towards a balance between innovation, In a century of vibrant growth, aviation has established itself under the pressure of very di ff erent paradigms Moore (2013). If in the first fifty years of intense innovation, the focus was on a rapid and absolute technical improvement of the vehicle, in a second period, the evolutionary path has been oriented towards a balance between innovation,

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the AIAS2019 organizers 10.1016/j.prostr.2020.02.047 ∗ Corresponding author. Tel.: 00390691292336. E-mail address: guido.zucca@studenti.unipg.it 2210-7843 c 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review line: Peer-review under responsibility of the AIAS2019 organizers. ∗ Corresponding author. Tel.: 00390691292336. E-mail address: guido.zucca@studenti.unipg.it 2210-7843 c 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review line: Peer-review under responsibility of the AIAS2019 organizers.