• norsk
    • English
  • English 
    • norsk
    • English
  • Login
View Item 
  •   Home
  • Fakultet for ingeniørvitenskap (IV)
  • Institutt for bygg- og miljøteknikk
  • View Item
  •   Home
  • Fakultet for ingeniørvitenskap (IV)
  • Institutt for bygg- og miljøteknikk
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Perforation of Welded Aluminium Structures

Breivik, Steffen Mikael Walnum; Thomsen, Espen Frøyen
Master thesis
Thumbnail
View/Open
747490_COVER01.pdf (184.3Kb)
747490_FULLTEXT01.pdf (35.15Mb)
URI
http://hdl.handle.net/11250/233116
Date
2014
Metadata
Show full item record
Collections
  • Institutt for bygg- og miljøteknikk [3699]
Abstract
The ballistic properties of three welded plates have been investigated, with special emphasis on the weld and heat affected zone (HAZ). The material is aluminium alloy EN AW-6082 T6 and the plates are 10, 20 and 30 mm thick. Physical experiments have been compared with numerical simulations. Material input for the numerical simulations have either been taken from direct calibration and inverse modelling of tensile tests, or from NaMo results provided by Dr. Ole Runar Myhr at Hydro Aluminium. NaMo, a software developed by Dr. Myhr, uses material composition and temperature history as input, and gives material parameters for any point in the material as output. The material models from tensile tests have also been combined with hardness measurements in order to estimate material parameters for selected points across the HAZ.Preliminary hardness measurements were taken to determine the weakest point of the HAZ, and these results were used to determine target positions for ballistic testing. A limited amount of ballistic experiments with 7.62 mm APM2 projectiles were performed. The exit velocity of the projectiles was higher in the HAZ for all three plates. In addition, the experiments targeting the weld itself revealed that this was somewhat stronger than the HAZ. Too few tests were performed in order to make a substantiated conclusion, however, trends were observed.The numerical ballistic simulations have been performed using the finite element code IMPETUS Afea Solver. Simulations overall gave non-conservative results, meaning that they overestimate the resistance of the plates. An initial model was calibrated with tensile tests from the base material of the 10 mm plate, and therefore these results are closest to the values given by ballistic experiments. The complete numerical model gave the best results for the HAZ. Tensile tests combined with hardness measurements overestimated the strength of the HAZ, i.e. the results were non-conservative.The Cylindrical Cavity Expansion Theory has been applied. With material parameters and geometry as input, it calculates the energy needed for perforation. Different material models have been tested, and generally the results are also with CCET, non-conservative. Thicker plates make the method less conservative.Relatively accurate results were obtained using the two pure numerical methods described.
Publisher
Institutt for konstruksjonsteknikk

Contact Us | Send Feedback

Privacy policy
DSpace software copyright © 2002-2019  DuraSpace

Service from  Unit
 

 

Browse

ArchiveCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsDocument TypesJournalsThis CollectionBy Issue DateAuthorsTitlesSubjectsDocument TypesJournals

My Account

Login

Statistics

View Usage Statistics

Contact Us | Send Feedback

Privacy policy
DSpace software copyright © 2002-2019  DuraSpace

Service from  Unit