Abstract
Due of their improved fire resistance, research on Rectangular Concrete-Filled Stainless-Steel Tubular [RCFSST] columns have recently attracted attention. The impacts of temperature gradient throughout the member length are highlighted in this investigation under post-fire conditions. After being exposed to high temperatures, 25 columns (4 short and 21 intermediate columns) were put to the test. Temperature ranges (600°C, 800°C, and 1000°C), exposure times (60, 120 minutes), exposure lengths (0.5L and L), major and minor axis loading, and various column kinds (short and intermediate) are some of the test variables. Plotting load-deformation curves allowed for the investigation of critical characteristics such initial compressive stiffness, failure mechanisms, and post-fire load capacity (Nup). Additionally, a Finite Element model was created and validated against the data. Half-exposed specimens were shown to have less strength loss. The residual strength and initial compressive stiffness were negatively impacted by high temperatures and temperature gradients, while completely exposed specimens were more negatively impacted by longer exposure times. Utilising parametric studies, a new reduction coefficient (R) formula is developed as a function of temperature (T), width to thickness (b/t), steel ratio (σ), and slenderness ratio (λ).
Key Words
elevated temperature; post fire strength; rectangular CFSST columns; temperature gradient; thin rectangular
stainless-steel section
Address
K. Anandapadmanaban: School of Civil Engineering, VIT Vellore, INDIA
A. Punitha Kumar: School of Civil Engineering, VIT Vellore, INDIA
A.S. Santhi: School of Civil Engineering, VIT Vellore, INDIA
Abstract
Lattice shells rely on axially dominated members where semi-rigid joints are common, yet most damage detection
frameworks remain global-level and do not provide design-ready residual capacity at the member level. This study proposes a
one-frequency damage quantification method that infers flexural stiffness reduction from the first natural frequency under elastic
end restraints, and a semi-rigid–aware capacity model that modifies the Perry–Robertson formulation via a corrected normalized
slenderness and a load-correction coefficient τ expressed as a linear function of the dimensionless stiffness ξ=kL2/(EI). The
approach is closed with a design workflow that maps damage severity to required FRP retrofit (type, ply number, fiber angle)
through equivalent-section transformation. Parametric FEM and external tests demonstrate that: (i) the proposed identification
reproduces stiffness loss with errors typically below 2% for semi-rigid and fixed ends; (ii) neglecting joint semi-rigidity yields
stability-coefficient errors exceeding 10% for the normalized slenderness ratio higher than 1.3. whereas the modified equation
limits errors to ≤2–6% with R2=0.98; and (iii) the retrofit workflow predicts axial capacity gains consistent with validated FEM
across 175 cases. The framework enables measure-once member-level diagnosis and design-oriented rehabilitation of lattice
structures with semi-rigid joints.
Address
Shu-Hui Huang:1)Key Laboratory of Earthquake Engineering and Engineering Vibration, Institute of Engineering Mechanics,
China Earthquake Administration; Key Laboratory of Earthquake Disaster Mitigation, Ministry of Emergency Management
2) School of Civil Engineering, Southeast University, Nanjing 210096, China
Wen-Jie Li:1)Key Laboratory of Earthquake Engineering and Engineering Vibration, Institute of Engineering Mechanics,
China Earthquake Administration; Key Laboratory of Earthquake Disaster Mitigation, Ministry of Emergency Management
2) School of Civil Engineering, Southeast University, Nanjing 210096, China
Ze Yang:School of Civil Engineering, Southeast University, Nanjing 210096, China
Ming-Liang Zhu:School of Civil Engineering, Southeast University, Nanjing 210096, China
Zhi-Wei Shan:1)Key Laboratory of Earthquake Engineering and Engineering Vibration, Institute of Engineering Mechanics,
China Earthquake Administration; Key Laboratory of Earthquake Disaster Mitigation, Ministry of Emergency Management
2) School of Civil Engineering, Southeast University, Nanjing 210096, China
Kun Liang:Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
Daniel Ting-Wee Looi:Civil Engineering, School of Engineering and Technology, Sunway University, Bandar Sunway, 47500 Selangor, Malaysia
Abstract
In recent decades continuous shear connectors have seen many improvements in research, developing many
different types of connectors and enhancing their shear resistance. Despite these advancements, numerous construction
companies still lean towards the traditional uncut I-beam for steel-concrete bridges, steel orthotropic deck bridges, or reinforced
concrete bridges, instead of embracing steel-concrete bridges with continuous shear connectors. This paper presents a study on a
shear connector in the form of a perfobond steel strip with an additional truss shear connection. This innovative design offers a
simpler construction solution while maintaining shear resistance. The experimental study consisted of two sets of experiments –
push-out tests and four-point flexural tests on a lightened beam. Furthermore, numerical models were created in finite element
method (FEM) software. Internal stresses of the shear connector were analyzed, with the breaking points being determined. A
parametric study was also carried out, investigating various diameters of the additional truss shear connector based on the
numerical models from the push-out tests. The paper concludes with a discussion on the overall behavior of the connector,
highlighting the determined ideal ratio between the steel web and truss diameter.
Key Words
composite bridge; finite element modeling; four-point flexural test; push-out test; shear connector
Address
Patricia Vanova:Faculty of Civil Engineering, Technical University of Kosice, Vysokoskolska 4, 042 00 Kosice
Daniel Dubecky:Faculty of Civil Engineering, Technical University of Kosice, Vysokoskolska 4, 042 00 Kosice
Michala Weissova:Faculty of Civil Engineering, Technical University of Kosice, Vysokoskolska 4, 042 00 Kosice
Martin Lavko:Faculty of Civil Engineering, Technical University of Kosice, Vysokoskolska 4, 042 00 Kosice
Viktoria Bajzecerova:Faculty of Civil Engineering, Technical University of Kosice, Vysokoskolska 4, 042 00 Kosice
Vincent Kvocak:Faculty of Civil Engineering, Technical University of Kosice, Vysokoskolska 4, 042 00 Kosice
Abstract
Functionally graded beams are very useful materials in structural and design engineering. In this article, we study an
analytical approach to analyze the dynamic response of functionally graded beams using Green's function coupled with a
perturbation method. Functionally graded materials are characterized by their continuous variation in composition and
properties, which provide superior performance under mechanical and thermal loads compared to traditional homogeneous
materials. The Green's function method is employed to establish a fundamental solution for the governing differential equations
of beam model, capturing the effects of graded material along the beam's length. The perturbation technique is then applied to
handle the non-homogeneous nature of the beam, allowing for an accurate approximation of the solution in the presence of small
variations in material properties. The effectiveness of the proposed method is demonstrated through several benchmark
problems, highlighting its capability to address complex boundary conditions and varying material distributions. The results
show that this combined approach offers significant improvements in computational efficiency and accuracy compared to
conventional numerical methods. The findings of this research provide a robust analytical tool for engineers and researchers to
predict the behavior of graded materials in various applications, contributing to the optimization and design of advanced
structural components. The solutions of such problems are also computed and displayed in graphical forms.
Key Words
Euler−Bernoulli beam; functionally graded beams; Green
Address
Hamza Hameed:1)Advanced Materials Science Laboratory, Computer Science Department, Green International University, Lahore, Pakistan
2)Software Engineering Department, Superior University, Lahore, Pakistan
3)Faculty of Science & Technology, University of Central Punjab, Lahore, Pakistan
4)Abdus Salam School of Mathematical Sciences, Government College University, Lahore-54000, Pakistan
Sadia Munir:Abdus Salam School of Mathematical Sciences, Government College University, Lahore-54000, Pakistan
F. D. Zaman:1)Abdus Salam School of Mathematical Sciences, Government College University, Lahore-54000, Pakistan
2)School of Mathematics, University of Witwatersrand, Johannesburg, South Africa
Shahbaz Ahmad:Abdus Salam School of Mathematical Sciences, Government College University, Lahore-54000, Pakistan
Abstract
This paper presents a comprehensive finite element (FE) study on the behaviour of high-strength steel (HSS)
circular hollow section (CHS) members with a circular perforation subjected to pure torsion. Validated FE models, against
existing test data, were developed and utilised in a broad parametric study considering different material grades (S700, S900,
and S1100), perforation sizes varying from 30% to 70% of the section diameter, and cross-section slenderness ratios ranging
from 2.5 to 400. The results show that torsional capacity decreases significantly with increasing perforation size, with slender
sections experiencing greater reductions than non-slender sections across all grades. Existing design provisions were found to be
inadequate for perforated HSS CHS members under torsion. To overcome this limitation, modified design equations were
proposed by extending current European and American code formulations, along with the Direct strength method and the
Continuous strength method, incorporating reduction factors. The proposed equations yield more accurate and reliable
predictions, thereby offering improved guidance for the safe and efficient design of perforated HSS CHS members.
Key Words
ircular hollow section; continuous strength method; direct strength method; finite element modelling; high
strength steel; perforation; torsional behaviour
Address
Soibam M. Devi:Department of Civil and Infrastructure Engineering, Indian Institute of Technology Jodhpur, India - 342030
Sanasam V. Devi:Department of Civil Engineering, National Institute of Technology Mizoram, India – 796012
Tekcham G. Singh:Department of Civil and Infrastructure Engineering, Indian Institute of Technology Jodhpur, India - 342030
Linxi Zhou, Siyuan Yang, Khidhair Jasim Mohammed, Meldi Suhatril, Ibrahim Albaijan5, Rania M.
Ghoniem, H. Elhosiny Ali, Hamid A. Zadeh and José Escorcia-Gutierrez
Abstract
Steel-Reinforced Concrete (SRC) panels with self-centering capability are increasingly applied in sports facility structures to withstand dynamic impacts; however, the interaction behavior of angle shear connectors under three-dimensional dynamic loading remains insufficiently explored, limiting optimization for impact resistance. This study analyses the dynamic 3D response of angle shear connector SRC panel systems under drop-weight impact, introducing a novel integration of self centering design into computational interaction modelling for sports facility applications. A detailed Finite Element (FE) model was developed incorporating nonlinear temperature-dependent material properties, explicit contact definitions, and realistic dynamic loading scenarios. Input parameters included panel geometry, connector dimensions, and impact velocity; outputs comprised displacement histories, connector stress distribution, and energy dissipation characteristics. Results show that self centering panels reduced residual displacement by 42 58% compared to conventional designs, with self-centering efficiencies (Ψₛ) consistently above 0.55 and reaching 0.82 under low-energy impacts. Connector stress utilization remained within ductile limits, peaking at 0.95 in the most severe cases without brittle fracture. Larger connectors decreased peak deflection by up to 12 % but increased local concrete bearing stresses by ~15 %. Elevated temperature exposure (Θ = 550 °C) reduced yield strength by 22 29 %, increasing peak displacement by 6 9 % and slightly lowering Ψₛ. Energy dissipation accounted for 58 65 % of initial kinetic energy, with 35 45 % from steel plasticity, 25 35 % from concrete damage, and the remainder from frictional slip. Boundary restraint stiffness had a more substantial influence on
Key Words
complex networks; mathematical simulation; mechanical behavior; nanotechnology
Address
Linxi Zhou:Chongqing Vocational Institute of Engineering, Chongqing, 402260, China
Siyuan Yang:Mingcheng Yucai School, Jiulongpo District, Chongqing, 400050, China
Khidhair Jasim Mohammed:Mechanical Power Technical Engineering Department, College of Engineering Technologies, Al Mustaqbal University, 51001, Hilla, Babylon, Iraq
Meldi Suhatril:Department of Civil Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia
Ibrahim Albaijan:Mechanical Engineering Department, College of Engineering at Alkharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 16273, Saudi Arabia
Rania M. Ghoniem:Department of Information Technology, College of Computer and Information Sciences,
Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riadh 11671, Saudi Arabia
H. Elhosiny Ali:Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia
Hamid A. Zadeh:1)Institute of Research and Development, Duy Tan University, Da Nang, Vietnam
2)School of Engineering & Technology, Duy Tan University, Da Nang, Vietnam
Jos é Escorcia-Gutierrez:Department of Computational Science and Electronics, Universidad de la Costa, CUC, Barranquilla, 080002, Colombia
Abstract
A novel prefabricated reinforced concrete (RC) beam-column joint, wrapped and connected by an outer square steel
tube in the core area, has been developed and widely used. In this design, the column's longitudinal reinforcement is anchored to
the inner diaphragm of the steel tube, while I-beams are pre-embedded at the beam ends. This design not only effectively
protects the core zone from damage and prevents rebar congestion but also facilitates the formation of plastic hinges within the
beam area, thereby reducing the risk of brittle failure during strong earthquakes. However, no prior study has investigated the
seismic performance of this novel prefabricated beam-column joint. To address this gap, this study performed a quasi-static
reversed cyclic loading test on two full-scale joints. The obtained test results demonstrate that the ductility coefficient and
equivalent damping coefficient of the prefabricated reinforced concrete beam-column joint are 3.152 and 0.134 respectively. It
exhibits strong abilities such as energy dissipation and deformation, which verifies the reliability of the joint design. And, the
steel tube preserves the integrity of the connection under cyclic loading. Additionally, A new formula for calculating the shear
strength of this type of joint was developed, and it is shown that the predicted results can be in good agreement with the
numerical results.
Abstract
As an eventual goal of various geotechnical experimental trials, a reliable assessment of the clay characteristics
combined with recycled materials was put into consideration. Some key physical and mechanical parameters of marine clay
(𝑀𝐶) amended with recycled tiles (𝑅𝑇) were used as independent variables in this study to estimate unconfined compressive
strength (𝑈𝐶𝑆). Four novel hybridized methods were formed, combining the extreme gradient boosting (𝑋𝐺𝐵) model with
various optimization algorithms such as the Black widow optimization algorithm (𝐵𝑊𝑂𝐴), Ant lion optimization (𝐴𝐿𝑂),
Arithmetic optimization algorithm (𝐴𝑂𝐴), and Moth flame optimization (𝑀𝐹𝑂). In the 𝑋𝐺𝐵 model, optimization methods
were utilized to determine the best appropriate value for determinative variables. Seven evaluation metrics were generated to
measure the models' correctness. As well, uncertainty with a 95% confidence level (𝑈95) was applied by the 𝑡𝑠𝑡𝑎𝑡𝑖𝑠𝑡𝑖𝑐 exam
(𝑇𝑠𝑡𝑎𝑡). The findings show that all four models have a high level of accuracy in their 𝑈𝐶𝑆 prediction procedures, demonstrating
the strong relationship between observations and predictions of the 𝑈𝐶𝑆 of mixed 𝑀𝐶, with 𝑅2 values for the learning and
evaluating collections of minimum 0.9674 and 0.9888, correspondingly. With 𝑆𝐼𝑇𝑟𝑎𝑖𝑛=0.0253 and 𝑆𝐼𝑇𝑒𝑠𝑡=0.0264, the
𝑂𝐴−𝑋𝐺𝐵 system has the least scatter index (𝑆𝐼) values in comparison with others (Excellent performance). The 𝐴𝑂𝐴−
𝑋𝐺𝐵 model clearly has the least 𝑈95, indicating that it has a higher generalization potential. Ultimately, the hybridized 𝐴𝑂𝐴−
𝑋𝐺𝐵 concept may outperform others to be acknowledged as a suggested one from this research after evaluating the
justifications of findings and comparisons with reviewed studies.
Key Words
extreme gradient boosting; marine clay; optimization
Address
Yiting Li: City Institute Dalian University of Technology, Dalian, China, 116600
Hong-da An:Dalian Minzu University School of Civil Engineering, Dalian, China, 116600
Hang Yin:Shenzhen University, Shenzhen, China, 518000
