Change search
ReferencesLink to record
Permanent link

Direct link
On the interply friction of different generations of unidirectional prepreg materials
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.ORCID iD: 0000-0002-6616-2964
2008 (English)In: Proceedings of 13th European Conference on Composite Materials (ECCM 13), 2008Conference paper (Refereed)
Abstract [en]

With the aim of reducing cost of prepreg composite components, manufacturing methods are developed and refined. An automatic tape laying machine can shorten the process cycle by stacking prepreg flat and thereafter allow for forming into desired shapes. Forming of stacked prepreg requires knowledge about the uncured properties of prepreg, such as viscosity of the matrix, intra- and interply deformation properties. This study focuses on the interply friction, i.e. the friction at the prepreg-prepreg interface, and how this affects the forming. The conclusions presented here show that the difference between prepreg material systems is significant. Further, it is concluded that the prepreg-prepreg friction is governed by a combination of Coulomb and hydrodynamic friction, where different mechanical phenomena dominate depending on the test conditions.

Place, publisher, year, edition, pages
Keyword [en]
prepreg, interply, friction
National Category
Vehicle Engineering Manufacturing, Surface and Joining Technology
Research subject
SRA - Production
URN: urn:nbn:se:kth:diva-10679OAI: diva2:224715
ECCM13: 13th European Conference on Composite Materials, 2 - 5 June 2008, Stockholm, Sweden
Kostnadseffektiva kompositer (KEKS)
XPRES - Initiative for excellence in production research

QC 20101015

Available from: 2013-01-28 Created: 2009-06-22 Last updated: 2016-08-11Bibliographically approved
In thesis
1. Deformability of unidirectional prepreg materials
Open this publication in new window or tab >>Deformability of unidirectional prepreg materials
2009 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

 To reduce cost of structural composites the development of more efficient manufacturing methods is of great interest. Sheet forming of thermoset prepreg, also known as hot drape forming, has been a promising manufacturing method for decades. An automatic tape layer (ATL) can be used to perform the lay-up in an efficient way. The flatly stacked unidirectional prepreg forms a sheet to be formed over a given mould. Knowledge about the materials forming behaviour is important to reach the required shape without flaws, such as wrinkles.

An experimental approach is developed to investigate the intra- (within the layer) and interply deformation. The intraply deformation properties are registered by the use of a bias-extension test and a digital image correlation (DIC) equipment. To measure the interlaminar (between the layers) friction in the prepreg/prepreg interface a specialized rig is designed and built.

The two tested materials are Cycom® HTA/977-2 from Cytec and HexPly® T700/M21 from Hexel, which are examples of the second and third generation of carbon fibre/epoxy prepreg. Where M21 includes craze stoppers in form of thermoplastic particles, the 977-2 has the same function but in melted stage. These particles seem to influence both the intraply deformation modes and increase the level of friction between layers.

The results from the bias-extension test was compared with the theory of pin-jointed net (PJN) and it was found that M21 behaves accordingly. The measured rotation for 977-2 is less than the theoretical, this due to slippage. The rate of deformation seems to have an influence not only on the load level, but also in the mode of deformation. Both for the interlaminar and intraply deformation the resistance to motion were much larger for M21 than 977-2.

Place, publisher, year, edition, pages
Stockholm: KTH, 2009. 25 p.
Trita-AVE, ISSN 1651-7660 ; 2009:32
prepreg, deformability, carbon composite
National Category
Vehicle Engineering
urn:nbn:se:kth:diva-10681 (URN)
2009-06-12, H1, Teknikringen 33, KTH, Stockholm, 13:15 (Swedish)
KEKS (kostnadseffektiva kompositer)
Available from: 2009-06-24 Created: 2009-06-23 Last updated: 2012-09-19Bibliographically approved

Open Access in DiVA

fulltext(295 kB)1 downloads
File information
File name FULLTEXT01.pdfFile size 295 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Other links

Search in DiVA

By author/editor
Larberg, YlvaÅkermo, Malin
By organisation
Lightweight Structures
Vehicle EngineeringManufacturing, Surface and Joining Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 1 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 185 hits
ReferencesLink to record
Permanent link

Direct link