{"title":"Influence of backing layers on the interlaminar fracture toughness energy – Mode I – of quasi-unidirectional GFRP","authors":"Simon Backens, Stefan Schmidt, W. Flügge","doi":"10.1515/mt-2024-0020","DOIUrl":null,"url":null,"abstract":"\n Quasi-unidirectional glass fiber non-crimp fabrics consist of a unidirectional main layer in the 0° direction stabilized by a backing layer in the 90° direction with a significantly lower amount of fibers. It is known that the backing layers impair the fatigue performance of respective reinforced plastics due to their orientation perpendicular to the main load direction. They act as damage initiators for the failure of the load-carrying unidirectional fibers. In the present work, the positive influence of the backing layers on the interlaminar fracture toughness energy – Mode I – G\n IC is demonstrated by tests in accordance with DIN EN 6033. The presence of backing fibers in the delamination plane can improve the G\n IC values by up to 43 %. Furthermore, results from evaluation according to DIN EN 6033 and ASTM D5528 are shown to have a good agreement, if the correction factor for large displacements recommended in the ASTM standard is not applied. If it is applied, however, there is a clear gap of up to 19 % between the two standards because the DIN simply does not provide a correction for large deflections.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.4000,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Testing","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1515/mt-2024-0020","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, CHARACTERIZATION & TESTING","Score":null,"Total":0}
引用次数: 0
Abstract
Quasi-unidirectional glass fiber non-crimp fabrics consist of a unidirectional main layer in the 0° direction stabilized by a backing layer in the 90° direction with a significantly lower amount of fibers. It is known that the backing layers impair the fatigue performance of respective reinforced plastics due to their orientation perpendicular to the main load direction. They act as damage initiators for the failure of the load-carrying unidirectional fibers. In the present work, the positive influence of the backing layers on the interlaminar fracture toughness energy – Mode I – G
IC is demonstrated by tests in accordance with DIN EN 6033. The presence of backing fibers in the delamination plane can improve the G
IC values by up to 43 %. Furthermore, results from evaluation according to DIN EN 6033 and ASTM D5528 are shown to have a good agreement, if the correction factor for large displacements recommended in the ASTM standard is not applied. If it is applied, however, there is a clear gap of up to 19 % between the two standards because the DIN simply does not provide a correction for large deflections.
准单向玻璃纤维非卷曲织物由 0° 方向上的单向主层和 90° 方向上的背层组成,背层的纤维量要少得多。众所周知,背衬层会损害增强塑料的疲劳性能,因为它们的取向与主载荷方向垂直。它们是承载负荷的单向纤维失效的损伤触发器。在本研究中,根据 DIN EN 6033 标准进行的测试证明了背衬层对层间断裂韧性能量(模式 I - G IC)的积极影响。在分层面上存在背衬纤维可将 G IC 值提高 43%。此外,根据 DIN EN 6033 和 ASTM D5528 标准进行的评估结果表明,如果不采用 ASTM 标准中建议的大位移校正系数,两者的一致性很好。但是,如果采用该修正系数,则两种标准之间的差距明显,最高可达 19%,因为 DIN 标准根本没有提供大位移修正系数。
期刊介绍:
Materials Testing is a SCI-listed English language journal dealing with all aspects of material and component testing with a special focus on transfer between laboratory research into industrial application. The journal provides first-hand information on non-destructive, destructive, optical, physical and chemical test procedures. It contains exclusive articles which are peer-reviewed applying respectively high international quality criterions.