Numerička analiza kompozitnog sjedala helikoptera pri vertikalnom udaru u tlo

master's thesis

• Title (english): Numerical analysis of a helicopter composite seat at vertical ground impact
• Author: Ana Mlinarević
• Mentor: Darko Ivančević (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-07-20, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

Ovaj rad bavi se numeričkom analizom kompozitnog sjedala helikoptera tokom vertikalnog udara o tlo u programskom paketu Abaqus/Explicit. Analiza se vrši na pojednostavljenom modelu konstrukcije sjedala helikoptera prema dostupnim podacima iz literature, kako bi se vidio utjecaj opterećenja koja sjedalo prenosi na putnike i posadu prilikom sudara.
Model sjedala je spojen s podnicom koja opisuje unutrašnji dio konstrukcije helikoptera i oslonjena je na ostatak pojednostavljenog modela konstrukcije poda kako bi se dobili što vjerodostojniji rezultati.
Sjedala, uz pod i podvozje helikoptera, dio su sustava za apsorpciju energije. Cilj izrade sjedala koja imaju neki oblik mehanizma za apsorbiranje energije je da se ublaži što više udar na čovjeka koji na njemu sjedi. Zbog nemogućnosti određivanja ponašanja sjedala tijekom udara analitičkim putem te skupog eksperimentalnog ispitivanja, koriste se numeričke simulacije koje predviđaju kako će se ono deformirati te koji će utjecaj imati na posadu. Na temelju toga, u radu je opisano eksperimentalno ispitivanje iz literature i dobiveni rezultati te je na kraju uspoređeno s provedenim simulacijama.
Izrađen je modela kompozitnih nogu sjedala helikoptera uzevši u obzir svojstva dva različita materijala u svrhu njihove kasnije usporedbe.
Nakraju je napravljena validacija numeričkog modela oštećenja i usporedba s dostupnim rezultatima ispitivanja udara kako bi se došlo do zaključka jesu li dobiveni numerički rezultati upotrebljivi za daljnja ispitivanja.

Abstract (english)

This thesis deals with the numerical analysis of a helicopter composite seat at vertical ground impact, in the Abaqus/Explicit software package. The analysis is performed on a simplified model of the helicopter seat structure according to the available data from the literature, in order to see the impact of the load that the seat transfers to the passengers and crew during the collision.
The seat model is connected to the floor which describes the inner part of the helicopter structure and is supported by the rest of the simplified floor structure model in order to obtain the most reliable results. The seats, along the floor and undercarriage of the helicopter are part of the energy absorption system. The goal of making seats that have some form of energy-absorbing mechanism is to soften the impact on the person sitting on them, as much as possible. Due to the impossibility of determining the behaviour of the seat during an impact analytically and expensive experimental testing, numerical simulations are emploved that predict how it will deform and what impact it will have on the crew. Based on this, the thesis describes the experimental test from the literature and the obtained results are finally compared with the performed simulations.
A model of composite helicopter seat legs was made, taking into account the properties of two different materials for the purpose of their later comparison. Finally, the numerical damage model was validated and compared with the available impact test resuts, in order to reach the conclusion whether the obtained numerical results are reliable for further tests.

• Keywords: Abaqus/Explicit; konstrukcija sjedala helikoptera; vertikalni udar; apsorpcija energije; validacija numeričkog modela
• Keywords (english): Abaqus/Explicit; helicopter seat design; vertical impact; energy absorption; numerical model validation
• Language: croatian
• URN:NBN: urn:nbn:hr:235:684367
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-07-16 12:27:53