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CONTENTS
Volume 85, Number 2, January25 2023
 


Abstract
Based on the ideas of variational differential quadrature (VDQ) and finite element method (FEM), a numerical approach named as VDQFEM is applied herein to study the large deformations of plate-type structures under static loading with arbitrary shape hole made of functionally graded graphene platelet-reinforced composite (FG-GPLRC) in the context of higherorder shear deformation theory (HSDT). The material properties of composite are approximated based upon the modified Halpin-Tsai model and rule of mixture. Furthermore, various FG distribution patterns are considered along the thickness direction of plate for GPLs. Using novel vector/matrix relations, the governing equations are derived through a variational approach. The matricized formulation can be efficiently employed in the coding process of numerical methods. In VDQFEM, the space domain of structure is first transformed into a number of finite elements. Then, the VDQ discretization technique is implemented within each element. As the last step, the assemblage procedure is performed to derive the set of governing equations which is solved via the pseudo arc-length continuation algorithm. Also, since HSDT is used herein, the mixed formulation approach is proposed to accommodate the continuity of first-order derivatives on the common boundaries of elements. Rectangular and circular plates under various boundary conditions with circular/rectangular/elliptical cutout are selected to generate the numerical results. In the numerical examples, the effects of geometrical properties and reinforcement with GPL on the nonlinear maximum deflection-transverse load amplitude curve are studied.

Key Words
cutout with arbitrary shape; finite element method; mixed formulation; nanocomposite plate

Address
Reza Ansari, Ramtin Hassani, Yousef Gholami: Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
Hessam Rouhi: Department of Engineering Science, Faculty of Technology and Engineering, East of Guilan, University of Guilan, P.C. 44891-63157, Rudsar-Vajargah, Iran

Abstract
The design of segmental bridges, a structure that typically employs precast prestressed concrete elements and the balanced cantilever construction method for the deck, may demand a highly complex structural analysis for increased precision of the results. This work presents a comprehensive numerical analysis of a 3D finite element model using the software ANSYS, version 21.2, to simulate the constructive deck stages of the New Guaiba Bridge, a structure located in Porto Alegre city, southern Brazil. The materials concrete and steel were considered viscoelastic. The concrete used a Generalized Kelvin model, with subroutines written in FORTRAN and added to the main model through the customization tool UPF (User Programmable Features). The steel prestressing tendons used a Generalized Maxwell model available in ANSYS. The balanced cantilever constructive steps of a span of the New Guaiba Bridge were then numerically simulated to follow the actual constructive sequence of the bridge. A comparison between the results obtained with the numerical model and the actual vertical displacement data monitored during the bridge's construction was carried out, showing a good correlation.

Key Words
ANSYS; balanced cantilever method; construction stages; finite element method; precast concrete; prestressed concrete; segmental bridges; UPF-User Programmable Features

Address
Gabriela G. Machado, Américo Campos Filho, Paula M. Lazzari, Bruna M. Lazzari and Alexandre R. Pacheco: Civil Engineering Graduate Program, Federal University of Rio Grande do Sul, 99 Osvaldo Aranha Ave., 90035-190, Porto Alegre, RS, Brazil

Abstract
The performance of reinforced concrete (RC) beam specimens strengthened using a newly proposed Side Near Surface Mounted (S-NSM) technology was investigated experimentally in this work. In addition, analytical and nonlinear finite element (FE) modeling was exploited to forecast the performance of RC members reinforced with S-NSM utilizing steel bars. Five (one control and four strengthened) RC beams were evaluated for flexural performance under static loading conditions employing four-point bending loads. Experimental variables comprise different S-NSM reinforcement ratios. The constitutive models were applied for simulating the non-linear material characteristics of used concrete, major, and strengthening reinforcements. The failure load and mode, yield and ultimate strengths, deflection, strain, cracking behavior as well as ductility of the beams were evaluated and discussed. To cope with the flexural behavior of the tested beams, a 3D non-linear FE model was simulated. In parametric investigations, the influence of S-NSM reinforcement, the efficacy of the S-NSM procedure, and the structural response ductility are examined. The experimental, numerical, and analytical outcomes show good agreement. The experimental findings were shown a significant increase in yield and ultimate strengths as well as improved failure modes.

Key Words
analytical model; ductility; flexural response; numerical model; S-NSM; steel bars; strengthening

Address
Md. Akter Hosen: Department of Civil and Environmental Engineering, College of Engineering, Dhofar University,
PO Box 2509, PC 211, Salalah, Sultanate of Oman
Mohd Zamin Jumaat: Department of Civil Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
A.B.M. Saiful Islam: Department of Civil & Construction Engineering, Imam Abdulrahman Bin Faisal University, 31451, Dammam, Saudi Arabia
Khalid Ahmed Al Kaaf: Department of Civil and Environmental Engineering, College of Engineering, Dhofar University, PO Box 2509, PC 211, Salalah, Sultanate of Oman
Mahaad Issa Shammas: Department of Civil and Environmental Engineering, College of Engineering, Dhofar University, PO Box 2509, PC 211, Salalah, Sultanate of Oman
Ibrahim Y. Hakeem: Civil Engineering Department, Najran University, Najran P.O. Box 1988, Saudi Arabia
Mohammad Momeen Ul Islam: Discipline of Civil and Infrastructure Engineering, School of Engineering, RMIT University, Melbourne, 3000, Victoria, Australia

Abstract
The deterioration caused by chloride penetration and carbonation plays a significant role in a concrete structure in a marine environment. The chloride corrosion in some marine concrete structures is invisible but can be dangerous in a sudden collapse. Therefore, as a novelty, this research investigates the ability of a non-destructive damage detection method named the Power Spectral Density (PSD) to diagnose damages caused only by chloride ions in concrete structures. Furthermore, the accuracy of this method in estimating the amount of annual damage caused by chloride in various parts and positions exposed to seawater was investigated. For this purpose, the RC Arosa bridge in Spain, which connects the island to the mainland via seawater, was numerically modeled and analyzed. As the first step, each element's bridge position was calculated, along with the chloride corrosion percentage in the reinforcements. The next step predicted the existence, location, and timing of damage to the entire concrete part of the bridge based on the amount of rebar corrosion each year. The PSD method was used to monitor the annual loss of reinforcement cross-section area, changes in dynamic characteristics such as stiffness and mass, and each year of the bridge structure's life using sensitivity equations and the linear least squares algorithm. This study showed that using different approaches to the PSD method based on rebar chloride corrosion and assuming 10% errors in software analysis can help predict the location and almost exact amount of damage zones over time.

Key Words
Chloride attack; concrete bridge; damage identification; non-destructive technique; Power Spectral Density method (PSD); steel corrosion

Address
Mehrdad Hadizadeh-Bazaz, Ignacio J. Navarro and Víctor Yepes: Department of Construction Engineering, Institute of Concrete Science and Technology (ICITECH), Universitat Politècnica de València, 46022 Valencia, Spain

Abstract
Three time-discontinuous Galerkin quadrature element methods (TDGQEMs) are developed for structural dynamic problems. The weak-form time-discontinuous Galerkin (TDG) statements, which are capable of capturing possible displacement and/or velocity discontinuities, are employed to formulate the three types of quadrature elements, i.e., single-field, singlefield/least-squares and two-field. Gauss-Lobatto quadrature rule and the differential quadrature analog are used to turn the weakform TDG statements into a system of algebraic equations. The stability, accuracy and numerical dissipation and dispersion properties of the formulated elements are examined. It is found that all the elements are unconditionally stable, the order of accuracy is equal to two times the element order minus one or two times the element order, and the high-order elements possess desired high numerical dissipation in the high-frequency domain and low numerical dissipation and dispersion in the lowfrequency domain. Three fundamental numerical examples are investigated to demonstrate the effectiveness and high accuracy of the elements, as compared with the commonly used time integration schemes.

Key Words
numerical dissipation and dispersion; quadrature element method; structural dynamics; time-discontinuous Galerkin; unconditional stability

Address
Minmao Liao and Yupeng Wanga: School of Civil Engineering, Chongqing University, Chongqing 400045, China

Abstract
The bending analysis of sandwich functionally graded (FG) beams under temperature circumstances is performed in this article utilizing Navier's solution-based parabolic shear deformation theory. For the first time, a comparative study has been carried out between the exponential and sigmoidal sandwich FGM beams under thermal conditions. During this investigation, temperature-dependent material characteristics are postulated. Both symmetric and unsymmetric sandwich examples have been studied. The effect of gradation law, gradation coefficient, and thickness scheme on beam behavior has been thoroughly investigated. Three possible temperature combinations at the top and bottom surfaces of the beam are also investigated. Beams with a higher proportion of ceramic to metal are shown to be more resistant to thermal stresses than beams with a higher proportion of metal.

Key Words
bending; Navier

Address
Aman Garg: Department of Multidisciplinary Engineering, The NorthCap University, Gurugram, Haryana, 122017, India
Mohamed-Ouejdi Belarbi: Laboratoire de Génie Energétique et Matériaux, LGEM, Faculté de la Science et de lo Technologie, Université de Biskra, B.P. 145, R.P. 07000, Biskra, Algeria
Li Li: State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Hanuman D. Chalak: Department of Civil Engineering, National Institute of Technology Kurukshetra, Kurukshetra, Haryana, 136119, India
Abdelouahed Tounsi: YFL (Yonsei Frontier Lab), Yonsei University, Seoul, Korea; Department of Civil and Environmental Engineering, King Fahd University of Petroleum &Minerals, 31261 Dhahran, Eastern Province, Saudi Arabia; Material and Hydrology Laboratory, Civil Engineering Department, Faculty of Technology, University of Sidi Bel Abbes, 22000 Sidi Bel Abbes, Algeria

Abstract
Bending and buckling analysis of multi-directional porous functionally graded sandwich plate has been performed for two cases namely: FG skin with homogeneous core and FG core with homogeneous skin. The principle of virtual displacements was employed and the solution was obtained using Navier's technique. This theory imposes traction-free boundary conditions on the surfaces and does not require shear correction factors. The validation of the present study has been performed with those available in the literature. The composition of metal-ceramic-based FGM changes in longitudinal and transverse directions according to the power law. Different porosity laws, such as uniform distribution, unevenly and logarithmically uneven distributions were used to mimic the imperfections in the functionally graded material that were introduced during the fabrication process. Several sandwich plates schemes were studied based on the plate's symmetry and the thickness of each layer. The effects of grading parameters and porosity laws on the bending and buckling of sandwich plates were examined.

Key Words
bending; buckling; multi-directional FGM; Navier

Address
Lazreg Hadji: 1Department of Civil Engineering, University of Tiaret, BP 78 Zaaroura, Tiaret, 14000, Algeria; Laboratory of Geomatics and Sustainable Development, University of Tiaret, 14000, Algeria; Faculty of Civil Engineering, Ton Duc Thang University, Ho Chi Minh City 70000, Vietnam
Fabrice Bernard: 4Laboratory of Civil Engineering and Mechanical Engineering, INSA Rennes, University of Rennes, France
Royal Madan: Department of Mechanical Engineering, G H Raisoni Institute of Engineering & Technology, Nagpur, Maharashtra, 440016, India
Ali Alnujaie, Mofareh Hassan Ghazwani: Mechanical Engineering Department, Faculty of Engineering, Jazan University, P.O. Box 114, Jazan, 45142, Kingdom of Saudi Arabia

Abstract
The paper deals with the study of the mechanical time-harmonic forced vibration of the hydro-piezoelectric system consisting of the piezoelectric plate and compressible viscous fluid with finite depth. The exact equations of motion of the theory of linear electro-elasticity for piezoelectric materials are employed for describing the plate motion, however, the fluid flow is described by employing the linearized Navier-Stokes equations for a compressible (barotropic) viscous fluid. The plane-strain state in the plate and the plane flow of the fluid are considered and the corresponding mathematical problems are solved by employing the Fourier transform with respect to the space coordinate which is on the coordinate axis directed along the platelying direction. The expressions of the corresponding Fourier transform are determined analytically, however, the inverse transforms are found numerically. Numerical results on the interface pressure and the electrical potential are obtained for various PZT materials and these results are discussed. According to these results, in particular, it is established that the electromechanical coupling effect can significantly decrease the interface pressure.

Key Words
compressible viscous fluid; electric potential; mechanical forced vibration; piezoelectric plate; plate -fluid interaction pressure

Address
Zeynep Ekicioglu Kuzeci: Department of Mechanical Engineering, Kirsehir Ahi Evran University, 40100, Kirsehir, Turkey
Surkay D. Akbarov: Department of Mechanical Engineering, Yildiz Technical University, 34349, Besiktas, Istanbul, Turkey; Institute of Mathematics and Mechanics of the National Academy of Sciences of Azerbaijan, AZ1141, Baku, Azerbaijan

Abstract
The spherical steel bearings (SSBs) has been gradually replaced traditional rubber bearings and extensively applied to high-speed railway (HSR) bridges in China, due to their durability and serviceability. Nevertheless, SSB is generally simplified to the ordinary constraints in the finite element model, which cannot reflect its detailed mechanical characteristics, especially its seismic performance. To provide a more precisely simulation, an innovative and simplified finite element simulation method is proposed and the combined element group is developed in ANSYS. The primary parameters were determined by means of the performance test of SSB. The finite element model of SSB applied to a single-span HSR simply supported girder bridge was established through the proposed method. The seismic performance of the SSB was further investigated. A shake table test was conducted to evaluate the accuracy of the proposed simulation method. It is found that the numerical results could have a good agreement with the experiment, namely, the proposed method is feasible and efficient.

Key Words
finite element simulation; high-speed railway bridge; shake table test; spherical steel bearing

Address
Renkang Hu, Shangtao Hu, Menggang Yang: School of Civil Engineering, Central South University, Changsha 410075, China; National Engineering Research Center of High-speed Railway Construction Technology, Central South University, Changsha 410075, China
Xiaoyu Zhang: School of Civil Engineering, Central South University, Changsha 410075, China
Na Zheng: Luoyang Sunrui Special Equipment Co., Ltd., Luoyang 471032, China

Abstract
The use of environmental-friendly building materials is becoming increasingly popular worldwide. Compared to the normal concrete, rubber-based concrete is considered more durable, environmentally friendly, socially and economically viable. In this investigation, M20 grade concrete was designed and the fine aggregates were replaced with crumb rubber of two different micron sizes (0.221 mm and 0.350 mm). Fly ash (FA) and silica fume (SF) replaces the binder as supplementary cementitious materials at a rate of 0, 5, 10, 15, and 20% by weight. The mechanical properties of concrete including compressive strength, tensile, and flexural strength were determined. The polynomial work expectation validates the response surface approach (RSM) concept for optimizing SF and FA substitution. The maximum compressive strength (22.53 MPa) can be observed for the concrete containing 10% crumb rubber, 15% fly ash and 15% silica fume. The reduced unit weight of the rubberized concrete may be attributed to the lower specific gravity of the rubber particles. Two-way ANOVA with a significance criterion of less than 0.001 has been utilized with modest residual error from the lack of fit and the pure error. The predictive model accurately forecasts the variable-response relationship. Since, the crumb rubber is obtained from wasted tires incorporating FA and SF as a cementitious ingredient, it helps to significantly improve mechanical properties of concrete and reduce environmental degradation.

Key Words
ANOVA; fly ash; RSM; rubber concrete; silica fume; sustainable concrete

Address
Muhammad Akbar: Department of Engineering Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China
Zahoor Hussain: School of Civil Engineering, Zhengzhou University, Zhengzhou 450001, China; Department of Civil Engineering, Sir Syed University of Engineering and Technology, Karachi, Pakistan
Pan Huali: Department of Engineering Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China
Muhammad Imran: Department of Civil Engineering, Sir Syed University of Engineering and Technology, Karachi, Pakistan
Blessen Skariah Thomas: Department of Civil Engineering, National Institute of Technology Calicut 673601, Kerala, India


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