Evaluation of mechanical properties of four different carbon/epoxy composites used in aeronautical field

Abstract

Four families of carbon fiber reinforced composites (CFRC) used in aeronautical industry were evaluated by flexural and interlaminar shear tests. It is also characterized three families of non-conditioned and conditioned CFRC by compression test. The composites were obtained by hand lay-up process in autoclave by using prepregs based on epoxy matrices (F155 and F584) and carbon fiber fabric reinforcements (PW-"Plain Weave" and 8HS-"Eight Harness Satin"). The F155-epoxy matrix was cured at 121 °C and the F584-epoxy type at 177 °C. After molding, the laminates were cut in specimens attending the ASTM D790 for the flexural test, the ASTM D2344 for the interlaminar shear test (ILSS) and the ASTM D3410 for the compressive test. The compressive tests were performed for testing the specimens before and after hygrothermal conditioning. The results show that the F584-epoxy matrix laminates present higher mechanical properties when compared to the F155-epoxy ones. The shear-tested samples observed by scanning electron microscopy and that ones tested in flexural, analyzed by stereoscopy, revealed that the fractured surfaces present typical aspects. The compressive results show that the hygrothermal conditioning caused the decrease of the compressive strength in, approximately, 8-20% depending on the laminate type. The failure modes of the tested specimens were evaluated showing good agreement with the literature

Mechanical and morphological characterizations of carbon fiber fabric reinforced epoxy composites used in aeronautical field

“…These results show that the F584 (modified epoxy, medium toughness) resin gives a higher flexural strength for the laminate composite than the 8552 (toughened epoxy, amine cured) epoxy system. Comparing the tendencies presented in this study and that one reported in literature 14 , it is also verified that the PW laminate confers a better flexural strength performance for the processed laminates.…”

“…A previous work 14 shows flexural strength results for F584/PW and F584/8HS laminates of 1288.5 ± 45.4 MPa and 1119.1 ± 43.2 MPa, respectively. These results show that the F584 (modified epoxy, medium toughness) resin gives a higher flexural strength for the laminate composite than the 8552 (toughened epoxy, amine cured) epoxy system.…”

“…These results show that both epoxy matrices present good performance in shear tests. In a previous work 14 , the authors show that the epoxy laminates based on F155/PW and F155/8HS present similar interlaminar shear strength values, 63.9 ± 1.8 MPa and 63.5 ± 3.5 MPa, respectively. F155 matrix is an epoxy resin without specific modifiers.…”

Tribological behaviour of unidirectional carbon fibre-reinforced epoxy composites

“…Fibre-reinforced composites have been used successfully for many decades as engineering applications such as aerospace, automobile, chemical, construction and ship/marine industries and sport equipment due to high specific strength and high modulus, wide varieties of availability and design flexibility as compared to metal based counterparts [1,2]. The application of carbon fibers as reinforcement in polymer composites has been continuously growing during the last few years.…”

Charpy impact toughness of conventional and advanced composite laminates for aircraft construction

“…TP laminates are highly sensitive to the epoxy resin employed, whereas the mechanical behavior of TC materials depends only slightly on the type of thermoset polymer. Paiva et al 19 , who performed flexural, interlaminar shear and compressive strength tests on identical TC laminates, also confirmed the superiority of thermoplastic-toughened composites over standard epoxy resin laminates. The authors attributed this behavior to the improved fiber/matrix interface provided by the rubber-toughened resin.…”