Shear-Dominated Bending Response of CFRP/Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves

Hasan Ulus

doi:10.17798/bitlisfen.1834444

Shear-Dominated Bending Response of CFRP/Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves

Abstract

Fiber–metal laminates (FMLs) that pair aluminum with CFRP offer an appealing balance of low weight and damage tolerance, yet their structural efficiency often depends on how well the composite–metal joints are designed. Here, we examine the shear-dominated flexural response of Al/CFRP sandwich joints and quantify how (i) stacking sequence and (ii) PAN nanofiber-interleaved toughening influence strength, energy absorption, and failure mode. Two laminate architectures were studied: Al–CFRP–Al (A–C–A) and CFRP–Al–CFRP (C–A–C). For each architecture, five joint concepts were produced using a structural epoxy: bolt-only (reference), neat bonded, PAN nanofiber-interleaved bonded, neat bonded/bolted hybrid, and nanofiber-bonded/bolted hybrid. Short-span three-point bending was selected to emphasize interlaminar and bondline shear, and load–displacement curves were used to extract maximum load, apparent interlaminar shear strength, total failure energy, and energy to maximum load, supported by post-failure observations. Nanofiber interleaves did not push bonded joints beyond the bolt-only peak-load level, but they markedly increased energy absorption and shifted failure from mainly adhesive debonding to mixed adhesive/cohesive fracture. Hybrid joints consistently outperformed both bonded and bolted configurations; with PAN toughening, nano-hybrid joints showed the highest loads and the most progressive, non-catastrophic response. Switching from A–C–A to C–A–C further enhanced strength and energy, especially for hybrids. The best-performing nanofiber-interleaved hybrid reached 6789 N (A–C–A) and 8406 N (C–A–C), about 52% and 90% above bolt-only, respectively, highlighting a robust route to simultaneous gains in strength, energy absorption, and damage tolerance.

Keywords

Project Number

Selçuk University Scientific Research Projects: Project No.25401041.

Ethical Statement

The study is complied with research and publication ethics.

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Details

Primary Language

English

Subjects

Composite and Hybrid Materials

Journal Section

Research Article

Authors

Hasan Ulus ^*
0000-0001-8591-8993
Türkiye

Publication Date

June 30, 2026

Submission Date

December 2, 2025

Acceptance Date

February 7, 2026

Published in Issue

Year 2026 Volume: 15 Number: 2

DOI

https://doi.org/10.17798/bitlisfen.1834444

IZ

https://izlik.org/JA25KD84JZ

Cite

RIS / Bibtex

APA

Ulus, H. (2026). Shear-Dominated Bending Response of CFRP/Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves. Bitlis Eren Üniversitesi Fen Bilimleri Dergisi, 15(2), 767-781. https://doi.org/10.17798/bitlisfen.1834444

AMA

1.Ulus H. Shear-Dominated Bending Response of CFRP/Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves. Bitlis Eren Üniversitesi Fen Bilimleri Dergisi. 2026;15(2):767-781. doi:10.17798/bitlisfen.1834444

Chicago

Ulus, Hasan. 2026. “Shear-Dominated Bending Response of CFRP Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves”. Bitlis Eren Üniversitesi Fen Bilimleri Dergisi 15 (2): 767-81. https://doi.org/10.17798/bitlisfen.1834444.

EndNote

Ulus H (June 1, 2026) Shear-Dominated Bending Response of CFRP/Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves. Bitlis Eren Üniversitesi Fen Bilimleri Dergisi 15 2 767–781.

IEEE

[1]H. Ulus, “Shear-Dominated Bending Response of CFRP/Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves”, Bitlis Eren Üniversitesi Fen Bilimleri Dergisi, vol. 15, no. 2, pp. 767–781, June 2026, doi: 10.17798/bitlisfen.1834444.

ISNAD

Ulus, Hasan. “Shear-Dominated Bending Response of CFRP Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves”. Bitlis Eren Üniversitesi Fen Bilimleri Dergisi 15/2 (June 1, 2026): 767-781. https://doi.org/10.17798/bitlisfen.1834444.

JAMA

1.Ulus H. Shear-Dominated Bending Response of CFRP/Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves. Bitlis Eren Üniversitesi Fen Bilimleri Dergisi. 2026;15:767–781.

MLA

Ulus, Hasan. “Shear-Dominated Bending Response of CFRP Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves”. Bitlis Eren Üniversitesi Fen Bilimleri Dergisi, vol. 15, no. 2, June 2026, pp. 767-81, doi:10.17798/bitlisfen.1834444.

Vancouver

1.Hasan Ulus. Shear-Dominated Bending Response of CFRP/Al Sandwich Joints: Influence of Stacking Sequence, Hybrid Bonding and PAN Nanofiber Interleaves. Bitlis Eren Üniversitesi Fen Bilimleri Dergisi. 2026 Jun. 1;15(2):767-81. doi:10.17798/bitlisfen.1834444