Scopus
YÖKSİS Eşleşti
Evaluating the influence of service conditions on the out-of-plane and in-plane loading performance and damage behavior of unidirectional CF/PEKK composites for aerospace applications
Composites Part B Engineering · Eylül 2025
YÖKSİS Kayıtları
Evaluating the Influence of Service Conditions on the Out-of-Plane and In-Plane Loading Performance and Damage Behavior of Unidirectional CF/PEKK Composites for Aerospace Applications
Composites Part B: Engineering · 2025 SCI
DOÇENT HASAN ULUS →
Makale Bilgileri
DergiComposites Part B Engineering
Yayın TarihiEylül 2025
Cilt / Sayfa304
Scopus ID2-s2.0-105006880306
Özet
Ensuring the structural reliability of composite materials requires a thorough understanding of their performance under various service conditions, particularly in demanding aerospace environments. This study investigates the influence of low-temperature (LT), high-temperature (HT), and cyclic-hygrothermal (CHT) conditions—representing a broad spectrum of realistic operational environments—on the out-of-plane and in-plane mechanical properties and damage behavior of unidirectional carbon fiber/poly-ether-ketone-ketone (CF/PEKK) composites. To assess the impact of these environmental factors on mechanical performance and failure mechanisms, a comprehensive experimental approach is employed, incorporating double-cantilever beam (DCB) tests with acoustic emission (AE) monitoring, end-notched flexure (ENF), short beam shear (SBS), and three-point bending (3-PB), alongside microscopic analysis. Results emphasize the significant influence of environmental conditions on the mechanical performance and damage evolution of CF/PEKK composites. Under LT conditions, flexural strength and deflection improve due to enhanced interlaminar interactions, despite increased brittleness in the matrix. LT conditioning yields the highest interlaminar shear strength (ILSS) and damage nucleation energy. However, LT-conditioned specimens exhibit brittle fractures with unstable crack propagation and frequent fiber-tow breakage during DCB and ENF tests. Conversely, HT conditions reduce flexural strength, but crack onset is delayed because of increased ductility. HT conditioning decreases ILSS and stiffness due to thermal softening. CHT conditioning results in intermediate flexural strength due to matrix plasticization, yet induces substantial inelastic deformation, multiple delaminations, and reduced interlaminar fracture toughness. These novel findings highlight the critical role of environmental factors in designing thermoplastic-based composites for aerospace applications, emphasizing the need for optimization to ensure reliable performance under diverse conditions.
Yazarlar (4)
1
Ceren Yildirim
2
Hasan Ulus
ORCID: 0000-0001-8591-8993
3
Hatice S. Sas
4
Mehmet Yildiz
ORCID: 0000-0003-1626-5858
Anahtar Kelimeler
Extreme service environments
Mechanical properties
Out-of-plane and in-plane loading
Structural health monitoring
Kurumlar
Sabancı Üniversitesi
Tuzla Turkey
Selçuk Üniversitesi
Selçuklu Turkey
The University of Sheffield
Sheffield United Kingdom