Abstract
Recent advancements in composite bridges have inspired new strategies for flexural reinforcement of metal box girders. This study analyzes the behavior of a simply supported steel box girder reinforced in bending with a prestressed CFRP composite plate, focusing on deflection, interface stresses, and interfacial slip. Two slab-girder connections are considered: studs and adhesive. Using both an analytical model and a 3D finite element model in Abaqus, the effects of prestressing force and CFRP content in hybrid plates are evaluated. Results show that higher prestressing force reduces deflection and stresses, while increasing CFRP content amplifies interface stresses. Interfacial slip is greater in I-beams than in box girders, and configurations
with multiple layers of prestressed CFRP offer the best performance by minimizing deflection and stabilizing stress distribution.
Key Words
analytical and numerical analysis; behavior of composite box girder bridges; reinforced composite plate
Address
T. Hassaine Daouadji, R. Benferhat, A. Rabahi, T. Bensatallah: Department of Civil Engineering, Ibn Khaldoun University of Tiaret, Algeria; Laboratory of Geomatics and Sustainable Development LGéo2D, University of Tiaret, Algeria
B. Abbes, F. Abbes: Laboratory Materials and Mechanical Engineering MATIM, University of Reims Cedex 2, France
Abstract
This paper investigates the large deformation behavior of thin flat and corrugated (crimp) steel plates used in
prefabricated blast-resistant modular structures through finite element simulations. The study evaluates plate responses under static monotonic, cyclic static, and dynamic blast loads using pressure-impulse (P-I) curves. Closed-form models based on yield line theory are developed to predict deflection-pressure curves for both flat and corrugated plates, showing strong agreement with finite element analysis. The results indicate that the pressure-deformation behavior of flat plates changes significantly upon yielding. Under cyclic loading, their stiffness decreases substantially until membrane action mitigates the effects during unloading, which also results in a notable reduction in hysteretic energy dissipation capacity. In contrast, the cyclic analysis of corrugated plates reveals decreased load-carrying capacity due to buckling from their profile, yielding, and plastic deformations. However, these plates exhibit substantial energy dissipation and maintain consistent initial stiffness throughout hysteretic loops, with minimal deviation. The findings highlight the significant influence of aspect ratio on plate behavior. Flat plates show a highly sensitive pressure-displacement relationship based on their aspect ratio, while corrugated plates exhibit minimal sensitivity in both static and dynamic conditions. Corrugated plates display consistent one-way bending behavior, largely independent of their aspect ratio. Dynamic blast analysis reveals that corrugated plates perform better in impulse-sensitive regions across all response levels, while flat plates excel in pressure-sensitive regions, particularly at medium and high levels.
Key Words
blast; corrugated plate; large plate deflection; membrane action; modular steel building
Address
Bülent Erkmen: Department of Civil Engineering, Faculty of Engineering, Ozyegin University, 34794 Istanbul, Türkiye
Ali Sari: Department of Civil Engineering, Faculty of Civil Engineering, Istanbul Technical University, 34469 Istanbul, Türkiye
Sezer Öztürk: Department of Civil Engineering, Faculty of Engineering, Fatih Sultan Mehmet Vakif University, 34015 Istanbul, Türkiye
Abstract
Fatigue, a critical concern in aeronautical engineering, arises from the repeated application of cyclic loads, which can lead to the initiation and growth of cracks over time. Such fatigue-induced cracks, particularly internal microcracks, are challenging to detect and can severely compromise components' structural integrity and service life. This study focuses on the fatigue behavior of aluminum alloy plates featuring a central crack subjected to cyclic loading, with particular attention to the impact of overload events and the efficiency of Boron/Epoxy composite patch repairs. The investigation is conducted on four aerospace-grade aluminum alloys—2024-T3, 2024-T861, 7075-T73, and 7075-T6. It examines the effect of load ratio on fatigue
crack propagation rates (oK) and provides a comparative analysis between unrepaired plates and those reinforced with
Boron/Epoxy patches. Additionally, the study evaluates the influence of overload ratios on fatigue life and crack growth dynamics, demonstrating that composite repairs can induce significant crack growth retardation. The results confirm the effectiveness of Boron/Epoxy patches in enhancing fatigue life and resistance to crack propagation under a range of loading conditions. Among the alloys tested, 2024-T3 displayed the most favorable fatigue performance. Overall, the findings underscore the critical role of material selection and repair strategy in extending the service life and ensuring the structural reliability of aeronautical components.
Key Words
fatigue crack propagation; overload effect; composite repair; Boron/Epoxy patch; ratio load
Address
Moulgada Abdelmadjid: Department of Mechanical Engineering, University of Ibn Khaldoun Tiaret, Algeria; Laboratory Mechanics Physics of materials (LMPM), University Djillali Liabes of Sidi Bel abbes, Algeria
Zagane Mohammed El Sallah: Department of Mechanical Engineering, University of Ibn Khaldoun Tiaret, Algeria; Laboratory Mechanics Physics of materials (LMPM), University Djillali Liabes of Sidi Bel abbes, Algeria
Ait Kaci Djafar: Department of Mechanical Engineering, University of Djillali Liabes Sidi Bel Abbes, Algeria; Laboratory Mechanics Physics of materials (LMPM), University Djillali Liabes of Sidi Bel abbes, Algeria
Benouis Ali: Laboratory Mechanics Physics of materials (LMPM), University Djillali Liabes of Sidi Bel abbes, Algeria; University of Moulay Tahar, Saida 20000, Algeria
Taibaoui Hiba: Department of Mechanical Engineering, University of Ibn Khaldoun Tiaret, Algeria
Bouab Daouia: Department of Mechanical Engineering, University of Ibn Khaldoun Tiaret, Algeria
Abstract
This paper focuses on the development of an analytical model based on a new refined parabolic shear deformation
theory (RPSDT) to address the static bending behavior of functionally graded sandwich (FGS) shallow shells with double curvature under transverse mechanical loading. The novelty of the proposed theory arises from the introduction of an improved kinematic model in which the transverse displacement is expressed as the sum of bending and shear components. This formulation is designed to reduce the number of unknowns and governing equations, and therefore exactly satisfies the shear stress-free boundary conditions on the upper and lower shell surfaces, thus eliminating the need for any shear correction factors. It provides a unified solution to the bending problems of doubly-curved shallow shells with varying geometrical properties, without the need to adjust the formulations and solution procedures. The sandwich shell structures consist of a homogeneous ceramic core and two FG face sheets, which have broad application in various fields of engineering and defense technology. The
mechanical properties of FG layers are assumed to vary gradually through the thickness direction, depending on a simple powerlaw distribution of the volume fractions of the constituents. The shell governing differential equations are derived using the principle of virtual work and are analytically solved by applying the Navier method for simply supported boundary conditions. The accuracy of the proposed theory is confirmed by the good agreement between the present predictions and the corresponding solutions found from the conventional shear deformation shell theories. From this investigation, it can be concluded that the present model, has proven to be computationally efficient and highly accurate in predicting the bending behavior of FGS shells.
Address
Kada Draiche: Department of Civil Engineering, University of Tiaret, BP 78 Zaaroura, 14000 Tiaret, Algeria; Material and Hydrology Laboratory, Civil Engineering Department, Faculty of Technology, University of Sidi Bel Abbes, Algeria
Emrah Madenci: Department of Civil Engineering, Necmettin Erbakan University, 42090, Konya, Turkey
Youcef Tlidji: Department of Civil Engineering, University of Tiaret, BP 78 Zaaroura, 14000 Tiaret, Algeria; Laboratoire Matériaux et Structures (LMS), University of Tiaret, Algeria
Abdelouahed Tounsi: Material and Hydrology Laboratory, Civil Engineering Department, Faculty of Technology, University of Sidi Bel Abbes, Algeria; Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Eastern Province, Saudi Arabia; Department of Civil and Environmental Engineering, Lebanese American University, 309 Bassil Building, Byblos, Lebanon
Abstract
Compared with conventional single-plate structures, double-layer plate configurations have gained widespread engineering applications owing to their enhanced compressive performance and vibration damping capabilities. Building upon Reddy's higher-order plate theory, this study develops an innovative spring-coupled bilayer model to examine wave propagation phenomena in graphene platelet-reinforced metal foam (GPLRMF) composite plates. Three distinct kinematic modes are investigated: in-phase, anti-phase (out-of-phase), and single-plate-fixed boundary conditions. The research framework comprises three key aspects: First, a refined displacement field formulation is established using higher-order shear deformation theory (HSDT). Second, the governing wave equation is derived through the Lagrangian variational principle. Finally, comprehensive parametric studies are conducted to evaluate the influences of material characteristics (GPL distribution patterns, porosity types), geometric parameters, thermal effects, and interfacial spring stiffness on wave propagation characteristics. The findings demonstrate that the GPL-C distribution pattern combined with Type-I porosity achieves superior wave propagation performance compared to other configurations. This work provides theoretical insights for designing tunable wave manipulation devices in advanced composite structures.
Address
Xiao-Qiang Sun: Chongqing Industry Polytechnic University, Chongqing, 401120, P.R. China; College of Aerospace Engineering, Chongqing University, Chongqing, 400044, P.R. China
Gui-Lin She: College of Mechanical and Vehicle Engineering, Chongqing University, Chongqing, 400044, China
Abstract
This paper presents the first part of a comprehensive numerical study investigating the seismic responses of guyed towers in different earthquake zones. For this purpose, nonlinear dynamic time history analyses were performed on nine towers (ranging from 60 to 519 meters) using 24 sets of earthquakes with a 50-year return period of 2% and 10% in Canada and the USA. This paper describes the details of towers, numerical modeling, and ground motions. The results of the bending moment and axial force of the towers are discussed. Furthermore, prediction equations for determining the maximum bending moment and axial force of towers in different earthquake zones are proposed. The results obtained from these proposed equations are compared with existing literature and show good agreement. Consequently, it can be concluded that the developed equations can
be used for practical applications in designing guyed towers for bending moment and axial force.
Key Words
axial force distribution; guyed towers; moment distribution; nonlinear dynamic analysis; seismic analysis
Address
Hussam M. Meshmesha: Department of Civil & Environmental Engineering, University of Windsor, Windsor, Canada
Khaled Sennah: Department of Civil Engineering, Toronto Metropolitan University, Toronto, Ontario, Canada
Ahad Javanmardi: College of Civil Engineering, Fuzhou University, Fuzhou, 350108, China; Centre for Infrastructure Engineering, Western Sydney University, Sydney, NSW 2000, Australia; Research and Development Center, PASOFAL Engineering, Sydney, NSW 2000, Australia
John B. Kennedy: Department of Civil & Environmental Engineering, University of Windsor, Windsor, Canada
