kth.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Geometric compensation of convex forming tools for successful final processing in concave cure tools – An experimental study
KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics. Saab AB, Bröderna Ugglas gata, Linköping, SE-581 88, Sweden.ORCID iD: 0000-0001-5567-1037
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.ORCID iD: 0000-0003-0613-2680
KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics.ORCID iD: 0000-0002-6616-2964
2019 (English)In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 116, p. 187-196Article in journal (Refereed) Published
Abstract [en]

To enable shimless composite part assembly it is desired to manufacture composite spars in concave, female tools. However, due to restricted access this process is often associated with a high degree of manual operations or expensive highly specialized production equipment. This study investigates a sequential manufacturing operation where the material is automatically laid up flat and hot formed onto a convex forming tool. Thereafter it is placed in the concave tool for curing. The study investigates four different ways to geometrically compensate the forming tool to simplify seating and enhance part quality. All compensations require material movement in-between forming and curing; this movement was tracked using Micro-CT. Micrographing and optical shape measurements show that a correct compensation provides high quality parts without adding labour intensive manufacturing steps.

Place, publisher, year, edition, pages
Elsevier BV , 2019. Vol. 116, p. 187-196
National Category
Composite Science and Engineering
Identifiers
URN: urn:nbn:se:kth:diva-312050DOI: 10.1016/j.compositesa.2018.10.030ISI: 000451491700020Scopus ID: 2-s2.0-85056199790OAI: oai:DiVA.org:kth-312050DiVA, id: diva2:1657160
Funder
Swedish Foundation for Strategic Research
Note

QC 20220510

Available from: 2022-05-10 Created: 2022-05-10 Last updated: 2022-06-25Bibliographically approved
In thesis
1. Tooling and processing for efficient and high tolerance prepreg composite manufacturing
Open this publication in new window or tab >>Tooling and processing for efficient and high tolerance prepreg composite manufacturing
2022 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Composite use is normally motivated in aircraft design by improved weight-specific mechanical properties as compared to metals. However, fatigue and dielectric properties may also be critical for material selection. In the modern world the environmental footprint, with reduced emissions in focus, will be lighter with the successful use of composites. Flight safety is the most important requirement for the aerospace industry. In order to benefit from the important properties which ensure the necessary performance of the aircraft, part materials must be according to material specification. This is not unique to the composite materials. However, since the composite material is often created simultaneously with the composite part, the manufacturing processes used are even more critical for a composite part than for a metal part. Tooling is required for most of the process steps in composite part manufacturing. The large number of tools required to complete a composite part and the relatively small series involved in most composite applications render tooling cost a major contributor to final part cost. This is especially true in the aeronautical field considering the high-quality requirements as concerns shape accuracy and laminate quality, as well as low production rates with annual production ranging from a few dozen to the rare thousands of parts. Since tooling adds a substantial contribution to the part cost, it is imperative to be aware of the different options available for each process step and how these affect process stability and cost. Göte Strindberg, a former technical director at Saab, often said “Ninety-nine per cent right can be one hundred per cent wrong in a composite manufacturing process”. Finding the correct parameters for the last per cent is key to composite part success. This has been the overall goal of this project. The beginning of the project focused on both process and tooling related improvements for hot-forming of prepreg laminates enabling new opportunities and improved ergonomics. The research results in improvements in laminate quality, for example, reduced thickness variation, and a significant increase in process efficiency. One conclusion is that an 80% reduction of cycle time can be achieved with maintained, or even improved, laminate quality. A novel method for compensation of forming tools is also presented. Research then continued with cure tool related issues. Shape fidelity and durability for composite cure tools was studied with the combined outcome of an in-depth understanding of composite cure tool performance at the elevated temperature and moisture conditions present during the use of the tools.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2022. p. 161
Series
TRITA-SCI-FOU ; 2022:10
Keywords
Tooling, Composite Manufacturing, Mould, Cure tool, Hot-forming, Compensation, Moisture, Shape distortion
National Category
Composite Science and Engineering
Research subject
Aerospace Engineering
Identifiers
urn:nbn:se:kth:diva-312115 (URN)978-91-8040-246-0 (ISBN)
Public defence
2022-06-08, https://kth-se.zoom.us/j/61052452396, F3, Lindstedtsvägen 26, Stockholm, 09:00 (English)
Opponent
Supervisors
Funder
Swedish Foundation for Strategic Research, ID15-0042
Note

QC 220512

Available from: 2022-05-12 Created: 2022-05-11 Last updated: 2022-06-25Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records

Grankäll, TommyHallander, PerÅkermo, Malin

Search in DiVA

By author/editor
Grankäll, TommyHallander, PerÅkermo, Malin
By organisation
Vehicle Engineering and Solid MechanicsAeronautical and Vehicle Engineering
In the same journal
Composites. Part A, Applied science and manufacturing
Composite Science and Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 75 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf