DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Experimental and numerical study of the spring-in of angled brackets manufactured using different resins and fiber textiles

Bernath, Alexander and Groh, Fabian and Exner, Wibke and Hühne, Christian and Hennig, Frank (2019) Experimental and numerical study of the spring-in of angled brackets manufactured using different resins and fiber textiles. Journal of Composite Materials. Sage Publications. doi: 10.1177/0021998319855423. ISSN 0021-9983.

Full text not available from this repository.


Process-induced distortion of composite structures often leads to a violation of tolerances, making the assembly of components difficult and expensive. It therefore can inhibit a cost-effective mass production of high-performance composite structures. Process-induced distortion is often introduced by curved regions of a part due to spring-in. Main drivers are chemical shrinkage of the resin and thermal expansion of both fiber and resin during cooling after demolding. Both contribute to residual strains and consequently lead to distortion of the manufactured part. The spring-in phenomenon has been already addressed in many studies. However, variations in manufacturing and specimen properties inhibit a detailed comparison of the results. Hence, it is difficult to isolate major influencing parameters. Here we show spring-in results of specimens that were manufactured using the very same experimental setup and laminate configuration but different resin and fiber types. It is therefore possible to identify the interaction of the curing temperature and the maximum achievable glass transition temperature of the individual resins as a major influencing factor. Furthermore, it is shown that the properties of the investigated resins do not differ largely in terms of thermal expansion and chemical shrinkage. Moreover, the latter was measured using two different techniques to enable a comparison. Numerical springin prediction revealed good accuracy throughout the investigated specimen configurations. Limitations found are the influence of the sewing of fiber textiles and the sensitivity of the model to gradual changes of the layup. Moreover, different homogenization techniques are compared with regard to spring-in prediction accuracy.

Item URL in elib:https://elib.dlr.de/129337/
Document Type:Article
Title:Experimental and numerical study of the spring-in of angled brackets manufactured using different resins and fiber textiles
AuthorsInstitution or Email of AuthorsAuthor's ORCID iDORCID Put Code
Bernath, AlexanderKarlsruher Institut für TechnologieUNSPECIFIEDUNSPECIFIED
Hühne, ChristianUNSPECIFIEDhttps://orcid.org/0000-0002-2218-1223UNSPECIFIED
Hennig, FrankKarlsruher Institut für TechnologieUNSPECIFIEDUNSPECIFIED
Journal or Publication Title:Journal of Composite Materials
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In ISI Web of Science:Yes
Publisher:Sage Publications
Keywords:Process-induced distortion, spring-in, angled bracket, chemical shrinkage, thermal expansion, residual strain, spring-in prediction
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Transport
HGF - Program Themes:Road Transport
DLR - Research area:Transport
DLR - Program:V ST Straßenverkehr
DLR - Research theme (Project):V - NGC Fahrzeugstruktur II (old)
Location: Braunschweig
Institutes and Institutions:Institute of Composite Structures and Adaptive Systems > Functional Lightweight Structures
Institute of Composite Structures and Adaptive Systems > Multifunctional Materials
Deposited By: Exner, Wibke
Deposited On:07 Oct 2019 05:08
Last Modified:27 Jun 2023 09:38

Repository Staff Only: item control page

Help & Contact
electronic library is running on EPrints 3.3.12
Website and database design: Copyright © German Aerospace Center (DLR). All rights reserved.