Low-energy impact issues in GLARE laminates
Jarosław Bieniaś, Patryk Jakubczak*, Barbara Surowska
Quarterly No. 3, 2013 pages 165-169
DOI:
keywords: GLARE laminates, low-energy impact, non-destructive testing, failure
abstract The purpose of the study is to present low-energy and low-velocity impact issues of hybrid laminates based on aluminium alloys connected with glass/epoxy composite (GLARE type) composites and conventional glass fibre reinforced polymer (GFRP) used in aerospace. The tested laminates were prepared by means of the autoclave method. Their reaction to low- velocity impact was analyzed using a hemispherical impactor (diameter 38.1 mm). The laminates were characterized in terms of damage size and failure mechanisms after impact with different energy levels (1.5 and 2.5 J). After the impact tests, the failure was evaluated using ultrasonic, microtomography and microscopic methods in order to determine the nature of internal degradation of the structure. It was noted that low-energy impact phenomena are of importance in aerospace materials. They cause barely visible impact damage to composite materials. However, the used FML are innovative materials characterized by higher low-velocity impact resistance because of the superior properties of both metals and fibrous composite materials with a strong adhesion bonding. The damage of GLARE laminates is much less than in polymer composites. Some transverse cracks and micro-delamination between the composite layers and in the adhesive layer are the major failure types in GLARE laminates as a result of low-energy impact.