Abstract
The paper deals with the development and application of the method for solving the dynamic problems related to the hollow eccentric cylinder made of linear elastic material. The investigations are carried out using the exact 3D linear theory of elastic waves. When satisfying the boundary conditions on the eccentric cylindrical surfaces, each term in the Fourier series, through which the solutions of the field equations are written, is once again represented in the form of the Fourier series. The method developed is based on this representation and differs from methods such as the Fourier collocation method and others used in solving dynamic problems for cylinders with complex cross-sections. The numerical results on the dispersion curves of the waves propagating in the eccentric hollow cylinder are presented and discussed. It is found that the eccentricity of the hollow cylinder leads to a significant change in the dispersion curves obtained for the corresponding co-axial cylinder. This change has not only quantitative character, but also qualitative character. Moreover, the advantages and disadvantages of the used method in contrast with other methods are discussed.
Address
Surkay D. Akbarov: Department of Mechanical Engineering, Yildiz Technical University, Istanbul, Turkey; Department of Theoretical and Continuum Mechanics, Baku State University, Baku, Azerbaijan
Sona S. Farajova: Department of Theoretical and Continuum Mechanics, Baku State University, Baku, Azerbaijan
Abstract
This paper introduces a precast concrete (PC) frame equipped with replaceable Jacketed Fuse-Type Mechanical Connectors (J-FTMC), referred to as "mechanical plastic hinges". The connector is a very effective tool as it allows for reliable
on-site assembly of the PC system. The proposed connection can control structural behavior and specifically designed to
concentrate seismic-induced damage that may occur during a credible earthquake. J-FTMC is currently recommended for use in beam-to-column connections to take advantage of energy dissipation, where relatively large rotation and plastic deformations are expected in PC frames. The earthquake-induced energy is dissipated within the mechanical plastic hinges owing to its strong post-yielding behavior. A quasi-static test was conducted in the laboratory on a nearly half-scale one-bay, two-story PC frame with mechanical plastic hinges to evaluate its seismic behavior. The contribution of the proposed mechanical plastic hinge was
investigated in terms of energy dissipation, damping, ductility, stiffness and strength degradation, self-entering capability, and failure modes. Test results concluded that plastic deformations were primarily concentrated at J-FTMCs with minimal damage observed in the beams and columns. The connectors exhibited excellent replaceability, as they were easily disassembled following the test. The frame achieved yield, and ultimate drifts were observed as 1% and 5% respectively with a maximum strength decrement of only 10% at 5% drift level. A pivot hysteretic type macro-model was generated to replicate the experimental results by assigning a group of equivalent spring elements. The numerical simulation results are in good agreement with the experiment results validating the effectiveness of the proposed modeling approach.
Key Words
energy dissipation; fuse type connector; plastic hinge; precast concrete frame; replaceable connection; seismic performance
Address
Hasan Özkaynak: Civil Engineering Department, İstanbul Beykent University, Ayazağa, 34398, Sariyer, İstanbul, Türkiye
Cihan Soydan: Civil Engineering Department, Tekirdağ Namik Kemal University, 59030, Tekirdağ, Türkiye
Melih Sürmeli: Civil Engineering Department, Bursa Technical University, 16310, Yildirim, Bursa, Türkiye
Erkan Şenol: Civil Engineering Department, Yeditepe University, 34755, Ataşehir, İstanbul, Türkiye
Hakan Saruhan: Civil Engineering Faculty, İstanbul Technical University, 34467, Sariyer, İstanbul, Türkiye
Ercan Yüksel: Civil Engineering Faculty, İstanbul Technical University, 34467, Sariyer, İstanbul, Türkiye
Abstract
In the design of long-lasting and reliable concrete pavement, it is essential to understand the response of Jointed Plain Concrete Pavement (JPCP) under various parameters like material properties, temperature variations, soil subgrade modulus, and traffic loading (single, tandem, and tridem). JPCP is generally constructed with different grades of concrete depending on the design requirements. The modulus of elasticity increases with the increase in the grade of the concrete. This study focuses on the effect of varying design parameters, such as modulus of elasticity, density of concrete, slab thickness, soil subgrade strength, loading, etc. on the flexural stresses in JPCP. Finite element (FE) models were developed using ABAQUS and SAP2000 software to simulate the pavement under various loadings based on realistic field conditions. The developed FE model has been validated, and the impact of change in modulus of elasticity on critical flexural stresses was studied. Guidelines like IRC 58 (2015) considered the effect of self-weight while calculating the stresses. In this study, the impact of self-weight was also observed on the critical stresses. Stresses are observed to be increased significantly due to the use of higher grades of concrete. However, design guidelines like IRC 58 (2015), IRC SP 62 (2014), and PCA (1984) consider a constant modulus of elasticity for evaluating the stresses developed in the slab. The conclusions of the study have significant implications for designers to understand how design parameters influence stresses and design thickness requirements. Moreover, this study also introduced a novel equation based on FE analysis to estimate the stresses due to the self-weight of the slab.
Key Words
concrete; finite element analysis; flexural stresses; jointed plain concrete pavement; modulus of elasticity
Address
Jeetendra S. Khichad: Department of Civil Engineering, North Eastern Regional Institute of Science and Technology (NERIST), Nirjuli, Itanagar, Arunachal Pradesh, 791109, India
Rameshwar J. Vishwakarma: Department of Civil Engineering, Malaviya National Institute of Technology, JLN Marg, Jaipur, Rajasthan, 302017, India
Abstract
This study numerically investigates the effect of material gradation on the nonlinear mechanical performance and load-carrying capacity of reinforced concrete (RC) beams externally strengthened with functionally graded material plates (FGMPs) bonded to the tension face. Using the ANSYS finite element platform, the research aims to quantify how varying gradation indices influence key structural performance metrics, including ultimate load capacity, mid-span deflection, stress and stress distribution across the beam–plate interface, and crack propagation behavior. The nonlinear constitutive behavior of concrete is modeled as quasi-brittle, while the FGMP is represented using a bilinear elastoplastic model. The smooth throughthickness variation of elastic and plastic properties within the FGM plate is defined using both the nonlinear power gradation law and the Tamura–Tomota–Ozawa (TTO) models. In the finite element framework, the RC beam and FGM plate are discretized using 3D solid elements (SOLID 65 for concrete and SOLID 185 for the plate), whereas the steel reinforcement is modeled
using LINK180 elements. The interaction between the concrete substrate and the FGMP is captured using a layered solid shell formulation (SOLSH 190) to simulate interfacial behavior accurately. Both static performance and failure modes are evaluated under incremental loading conditions. The validity of the proposed FE model is established through comparison with existing literature, demonstrating strong agreement between the results. The effects of functionally graded material distributions, gradation index, and plate thickness on load capacity, maximum deflection, induced interfacial stresses, and crack patterns are examined and analyzed. The findings reveal that FGMPs with higher ceramic content significantly enhance the beam's stiffness, ultimate load capacity, and resistance to cracking. The outcomes of this study contribute to the development of reliable computational tools for designing FGM strengthened RC structures subjected to complex mechanical loading.
Key Words
comprehensive computational methodology; elastoplastic functionally graded materials; load carrying capacity; nonlinear mechanical performance; strengthening RC beams; Tamura, Tomota and Ozawa (TTO) model
Address
Alaa A. Abdelrahman: Mechanical Design & Production Engineering Department, Faculty of Engineering, Zagazig University, P.O. Box 44519, Zagazig, Egypt; Industrial Engineering Department, Jeddah International College (JIC), P.O. Box 23831, Jeddah, Saudi Arabia
Hanaa E. Abd-El-Mottaleb: Department of Structural Engineering, Faculty of Engineering, Zgazig University, P.O. Box 44519, Zagazig, Egypt
Mohamed G. Elblassy: Department of Structural Engineering, Faculty of Engineering, Zgazig University, P.O. Box 44519, Zagazig, Egypt
AbdulAleem M. Al-Obaisi: Mechanical Engineering Department, Faculty of Engineering, King Abdulaziz University, Jeddah 21589, Saudi Arabia
A.M. Sadoun: Mechanical Design & Production Engineering Department, Faculty of Engineering, Zagazig University, P.O. Box 44519, Zagazig, Egypt; Mechanical Engineering Department, Faculty of Engineering, King Abdulaziz University, Jeddah 21589, Saudi Arabia
Eman A. Elshamy: Department of Structural Engineering, Faculty of Engineering, Zgazig University, P.O. Box 44519, Zagazig, Egypt; Dean of Obour High Institute of Engineering and Technology, Masr-Al Ismailia Desert Rd., Obour, Cairo, Egypt
Abstract
of mass, stiffness, and strength along the height of the structure. During earthquakes, buildings with various degrees of irregularity are commonly found to collapse, resulting in property loss and casualties. This paper presents extensive documentation of post-earthquake damage surveys conducted worldwide over the past three decades to understand different types of failure in RC structures. The severe damage resulting from past earthquakes was discussed, and then studies on softstorey buildings using numerical, analytical, and experimental methods were covered. Different codal provisions for soft-storey buildings and their recommendations for reducing earthquake effects are also discussed at a later stage. In summary, this study intends to provide an overview of seismic upgrading methods as well as several retrofitting and strengthening approaches for
soft-storey buildings, which can be utilised to examine how these structures behave during a seismic event and improve the seismic performance of the structures to reduce the causalities during earthquakes.
Key Words
Codal provisions; mass irregularity; seismic performance; soft storey behaviour; stiffness irregularity; strength irregularity
Address
Shibajee Sutar, Lipika Halder: Department of Civil Engineering, National Institute of Technology Agartala, Tripura, India.
Pranoy Debnath: Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, India
Abstract
This study introduces a novel framework for the multi-objective optimization of steel-concrete composite footbridges, integrating fire resilience with sustainability metrics such as cost, CO2 emissions, and pedestrian comfort. While previous research has largely focused on ambient or simplified fire conditions, this work uniquely incorporates six fire exposure scenarios, ranging from 200 to 1500 seconds, to assess structural performance under extreme conditions. Employing a customdeveloped Multiobjective Harmony Search (MOHS) algorithm, the optimization identifies Pareto-optimal solutions that balance economic and environmental efficiency with pedestrian comfort and fire safety. The results reveal a linear relationship between cost and CO2 emissions, demonstrating that each US$ 1.00 saved reduces emissions by 0.7727 kg per meter. Additionally, a moderate 23% cost increase enhances fire resistance, preventing collapse during 10 minutes of fire exposure, while smaller investments of 3.91% and 15.06% extend safety for 200 and 400 seconds, respectively. These findings highlight the critical trade-offs between slender, cost-effective designs and compact, fire-resilient configurations. By addressing both fire scenarios and sustainability in a single optimization process, this research offers new insights into designing safer, more sustainable footbridges, with practical implications for urban infrastructure development.
Key Words
fire safety; multiobjective optimization; steel-concrete composite structure; sustainability; vibrations
Address
Fernando L. Tres Junior: Institute of Concrete Science and Technology (ICITECH), Universitat Politècnica de València,
Camino de Vera s/n, Valencia 46022, Spain
Guilherme F. de Medeiros: Civil and Environmental Engineering Graduate Program (PPGEng), University of Passo Fundo, BR 285 Km 292,7, Passo Fundo 99052-900, Brazil
Moacir Kripka: Civil Engineering Graduate Program (PPGEC), Federal University of Technology-Paraná, Via do Conhecimento Km 1, Pato Branco 85503-390, Brazil
Victor Yepes: Institute of Concrete Science and Technology (ICITECH), Universitat Politècnica de València,
Camino de Vera s/n, Valencia 46022, Spain
