Structural Engineering and Mechanics

Volume 96, Number 2, 2025, pages 131-138

DOI: 10.12989/sem.2025.96.2.131

Investigation of the effect of composite patch repair on the life of a plate with two lateral cracks

Moulgada Abdelmadjid, Zagane Mohammed El Sallah, Ait Kaci Djafar, Sahli Abderahmane, Murat Yaylaci, İrem Mirzaloğlu, Mehmet Emin Özdemir and Ecren Uzun Yaylaci

Abstract

This paper presents a study on the effect of composite patch repair on the fatigue life of an aluminum alloy plate containing two lateral cracks and subjected to cyclic tensile stresses applied to its upper and lower parts. The investigation considers several parameters, including the load ratio between minimum and maximum stresses (0, 0.3, 0.6, and 0.7), the cracking speed as a function of the stress intensity factor (tK), and the influence of the plate material. Among the alloys examined were 2024-T3, 2024-T351, and 7075-T73. The study identifies the material most resistant to cyclic loading. The plate is analyzed in both unrepaired and repaired conditions, with repairs performed using two different composite patches: boron/epoxy and graphite/epoxy. The results demonstrate that patch reinforcement significantly improves fatigue resistance, with boron/epoxy patches providing the greatest enhancement. The study concluded that the AL 2024-T3 material presents better results compared to the other two materials. These findings confirm the effectiveness of composite patching as a promising technique for extending the service life of cracked structures.

Key Words

cracking; lifetime; load ratio; patches; plate; stress

Address

Moulgada Abdelmadjid: Department of Mechanical Engineering, University of Ibn Khaldoun Tiaret, City Zaaroura BP 78 Tiaret, 14000, Algeria; Laboratory of Mechanical and Physics of Materials LMPM, University of Djillali Liabes Sidi Bel Abbes, 22000, Algeria Zagane Mohammed El Sallah: Department of Mechanical Engineering, University of Ibn Khaldoun Tiaret, City Zaaroura BP 78 Tiaret, 14000, Algeria; Laboratory of Mechanical and Physics of Materials LMPM, University of Djillali Liabes Sidi Bel Abbes, 22000, Algeria Ait kaci Djafar: Laboratory of Mechanical and Physics of Materials LMPM, University of Djillali Liabes Sidi Bel Abbes, 22000, Algeria; Department of Mechanical Engineering, University of Djillali Liabes Sidi Bel Abbes, 22000, Algeria Sahli Abderahmane: Laboratory of Mechanical and Physics of Materials LMPM, University of Djillali Liabes Sidi Bel Abbes, 22000, Algeria; Department of Mechanical Engineering, University of Djillali Liabes Sidi Bel Abbes, 22000, Algeria Murat Yaylaci: Department of Civil Engineering, Recep Tayyip Erdogan University, 53100, Rize, Turkey; Turgut K