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CONTENTS
Volume 84, Number 6, December25 2022
 


Abstract
In this study, a new refined hyperbolic shear deformation theory (RHSDT) is developed using an equivalent singlelayer shell displacement model for the static bending and free vibration response of cross-ply laminated composite spherical shells. It is based on a new kinematic in which the transverse displacement is approximated as a sum of the bending and shear components, leading to a reduction of the number of unknown functions and governing equations. The proposed theory uses the hyperbolic shape function to account for an appropriate distribution of the transverse shear strains through the thickness and satisfies the boundary conditions on the shell surfaces without requiring any shear correction factors. The shell governing equations for this study are derived in terms of displacement from Hamilton's principle and solved via a Navier-type analytical procedure. The validity and high accuracy of the present theory are ascertained by comparing the obtained numerical results of displacements, stresses, and natural frequencies with their counterparts generated by some higher-order shear deformation theories. Further, a parametric study examines in detail the effect of both geometrical parameters (i.e., side-to-thickness ratio and curvature-radius-to-side ratio), on the bending and free vibration response of simply supported laminated spherical shells, which can be very useful for many modern engineering applications and their optimization design.

Key Words
bending; cross-ply laminated composite; free vibration; RHSDT; spherical 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
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; YFL (Yonsei Frontier Lab), Yonsei University, Seoul, Korea

Abstract
Functionally graded materials (FGMs) have been spotlighted as an advanced composite material, accordingly the intensive studies have focused on FGMs to examine their mechanical behaviors. Among them is thermal buckling which has been a challenging subject, because its behavior is connected directly to the safety of structural system. In this context, this paper presents the numerical analysis of thermal buckling of metal-ceramic functionally graded (FG) plates. For an accurate and effective buckling analysis, a new numerical method is developed by making use of (1,1,0) hierarchical model and 2-D natural element method (NEM). Based on 3-D elasticity theory, the displacement field is expressed by a product of 1-D assumed thickness monomials and 2-D in-plane functions which are approximated by NEM. The numerical method is compared with the reference solutions through the benchmark test, from which its numerical accuracy has been verified. Using the developed numerical method, the critical buckling temperatures of metal-ceramic FG plates are parametrically investigated with respect to the major design parameters.

Key Words
critical buckling temperature; hierarchical model; metal-ceramic FG plate; natural element method (NEM); parametric investigation; thermal buckling analysis

Address
J.R. Cho: Department of Naval Architecture and Ocean Engineering, Hongik University, Sejong, 30016, Korea

Abstract
The amount of natural gas that is used on a worldwide scale is continuously going up. Natural gas and acidic components, such as hydrogen sulfide and carbon dioxide, cause significant corrosion damage to transmission lines and equipment in various quantities. One of the fundamental processes in natural gas processing is the separation of acid gases, among which the safety and environmental needs due to the high toxicity of hydrogen sulfide and also to prevent wear and corrosion of pipelines and gas transmission and distribution equipment, the necessity of sulfide separation Hydrogen is more essential than carbon dioxide and other compounds. Given this problem's significance, this endeavor aims to extend the lifespan of the transmission lines' pipes for gas and oil. Zinc oxide nanoparticles made from the environmentally friendly source of Allium scabriscapum have been employed to accomplish this crucial purpose. This is a simple, safe and cheap synthesis method compared to other methods, especially chemical methods. The formation of zinc oxide nanoparticles was shown by forming an absorption peak at a wavelength of about 355 nm using a spectrophotometric device and an X-ray diffraction pattern. The size and morphology of synthesized nanoparticles were determined by scanning and transmission electron microscope, and the range of size changes of nanoparticles was determined by dynamic light scattering device.

Key Words
gas; Green synthesis; life extending; nanoparticles; oil; pipeline

Address
Yunye Liu: School of Petroleum Engineering, China University of Petroleum (East China), 266580, Qingdao, China
Hai Zhu: Guangzhou Gas Group South Branch, 510440, Guangzhou, China
Jianfeng Niu: Henan YUNENG Holdings Company Limited, Zhengzhou, China

Abstract
Near-surface excavations may cause the tilting and destruction of the adjacent superstructures in big cities. The stability of a huge excavation and its nearby superstructures was studied in this paper. Some test instruments monitored the deformation and loads at the designed location. Then the numerical models of the excavation were made in FLAC3D (a threedimensional finite difference code) and Plaxis-3D (a three-dimensional finite element code). The effects of different supporting and reinforcement tools such as nails, piles, and shotcretes on the stability and bearing capacity of the foundation were analyzed through different numerical models. The numerically approximated results were compared with the corresponding in-field monitored results and reasonable compatibility was obtained. It was concluded that the displacement in excavation and the settlement of the nearby superstructure increases gradually as the depth of excavation rises. The effects of support and reinforcements were also observed and modeled in this study. The settlement of the structure gradually decreased as the supports were installed. These analyses showed that the pile significantly increased the bearing capacity and decreased the settlement of the superstructure. As a whole, the monitoring and numerical simulation results were in good consistency with one another in this practically important project.

Key Words
excavation; field measurements; FLAC3D; nail; pile; Plaxis 3D; shotcrete

Address
Lei Zhou: State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Failure Mechanics and Engineering Disaster Prevention, Key Laboratory of Sichuan Province, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Zahra Jalalichi: Department of Mining Engineering, Amirkabir University of Technology, Tehran, Iran
Vahab Sarfarazi: Department of Mining Engineering, Hamedan University of Technology, Hamedan, Iran
Hadi Haeri: Department of Mining Engineering, Higher Education Complex of Zarand, Zarand, Iran
Parviz Moarefvand: Department of Mining Engineering, Amirkabir University of Technology, Tehran, Iran
Mohammad Fatehi Marji: Department of Mining Engineering, Yazd University, Yazd, Iran
Shahin Fattahi: Department of Mining Engineering, Higher Education Complex of Zarand, Zarand, Iran

Abstract
In this paper, the nonlinear vibration behavior of the spiral stiffened multilayer functionally graded (SSMFG) cylindrical shells exposed to the thermal environment and a uniformly distributed harmonic loading using a semi-analytical method is investigated. The cylindrical shell is surrounded by a nonlinear viscoelastic foundation consisting of a two-parameter Winkler-Pasternak foundation augmented by a Kelvin-Voigt viscoelastic model with a nonlinear cubic stiffness. The distribution of temperature and material constitutive of the stiffeners are continuously changed through the thickness direction. The cylindrical shell has three layers consisting of metal, FGM, and ceramic. The interior layer of the cylindrical shell is rich in metal, while the exterior layer is rich in ceramic, and the FG material is located between two layers. The nonlinear vibration problem utilizing the smeared stiffeners technique, the von Kármán equations, and the Galerkin method has been solved. The multiple scales method is utilized to examine the nonlinear vibration behavior of SSMFG cylindrical shells. The considered resonant case is 1:3:9 internal resonance and subharmonic resonance of order 1/3. The influences of different material and geometrical parameters on the vibration behavior of SSMFG cylindrical shells are examined. The results show that the angles of stiffeners, temperature, and elastic foundation parameters have a strong effect on the vibration behaviors of the SSMFG cylindrical shells.

Key Words
multilayer FG cylindrical shells; internal resonances; spiral stiffeners; thermal environment; nonlinear viscoelastic foundation; subharmonic of order 1/3

Address
Kamran Foroutan and Habib Ahmadi: Faculty of Mechanical and Mechatronics Engineering, Shahrood University of Technology, Shahrood, Iran

Abstract
This study attempts to investigate the impact of thickness stretching and nonlinear hygro-thermo-mechanical loading on the bending behavior of FG beams. Young

Key Words
bending behavior: FG beams; nonlinear hygro-thermo-mechanical loading; thickness stretching

Address
Faicel Khadraoui: Laboratory of Materials and Reactive Systems, Department of Mechanical Engineering, University of Sidi Bel Abbes, Faculty of Technology, Algeria; Department of Mechanical Engineering, University of Abbès Laghrour Khenchela, Faculty of Science and Technology, Algeria
Abderahmane Menasria, Belgacem Mamen, Abdelhakim Bouhadra:
Fouad Bourada: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Algeria; Department of Civil Engineering, University of Abbés Laghrour Khenchela, Faculty of Science and Technology, Algeria
Soumia Benguediab: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Algeria; Département des Sciences et de la Technologie, Université de Tissemsilt, BP 38004 Ben Hamouda, Algérie; Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Algeria; Université Dr Tahar Moulay, Faculté de Technologie, Département de Génie Civil et Hydraulique, BP 138 Cité En-Nasr 20000 Saida, Algérie
Kouider Halim Benrahou: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Algeria; Princess Nourah bint Abdulrahman University, Saudi Arabia
Mohamed Benguediab: Laboratory of Materials and Reactive Systems, Department of Mechanical Engineering, University of Sidi Bel Abbes, Faculty of Technology, Algeria
Abdelouahed Tounsi: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Algeria; 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

Abstract
Adhesive bonding has seen rapid development in recent years, with emphasis to composite patch repairing processes of geometric defects in aeronautical structures. However, its use is still limited given its low resistance to climatic conditions and requirement of specialized labor to avoid fabrication induced defects, such as air bubbles, cracks, and cavities. This work aims to numerically analyze, by the finite element method, the failure behavior of a damaged plate, in the form of a bonding defect, and repaired by an adhesively bonded composite patch. The position and size of the defect were studied. The results of the numerical analysis clearly showed that the position of the defect in the adhesive layer has a large effect on the value of J-Integral. The reduction in the value of J-Integral is also related to the composite stacking sequence which, according to the mechanical properties of the ply, provides better load transfer from the plate to the repair piece through the adhesive. In addition, the increase in the applied load significantly affects the value of the J-Integral at the crack tip in the presence of a bonding defect, even for small dimensions, by reducing the load transfer.

Key Words
bonding defect; J-integral; peel stress; repair patch; shear stress

Address
N. Kaddouri, K. Madani, S.CH. Djebbar, M. Belhouari: Department of Mechanical Engineering, University of Sidi Bel Abbes, BP 89 Cité Ben M

Abstract
In this article, the buckling and free vibration of multi-directional FGM sandwich plates are investigated. The material properties of FGM sandwich plates are assumed to be varying continuously in the in the longitudinal, transverse and thickness directions. The material properties are evaluated based on Voigt's micro-mechanical model considering power law distribution method with arbitrary power index. Equations of motion for the buckling and vibration analysis of multi-directional FGM sandwich plate are obtained based on refined shear deformation theory. Analytical solution for simply supported multidirectional FGM sandwich plate is carried out using Navier's solution technique. The FGM sandwich plate considered in this work has a homogeneous ceramic core and two functionally graded face sheets. Influence of volume fraction index in the longitudinal, transverse and thickness direction, layer thickness, and geometrical parameter over natural frequency and critical buckling load of multi-directional FGM sandwich plate is investigated. The finding shows a multi-directional functionally graded structures perform better compared to uni-directional gradation. Hence, critical grading parameters have been identified which will guide researchers in selecting fabrication routes for improving the performance of such structures.

Key Words
buckling; FGM sandwich plate; free vibration; multi-directional FGM

Address
Ali Alnujaie: Mechanical Engineering Department, Faculty of Engineering, Jazan University, P.O. Box 45142, Jazan, Saudi Arabia
Atteshamuddin S. Sayyad: Department of Structural Engineering, Sanjivani College of Engineering, Savitribai Phule Pune University, Kopargaon, 423601, Maharashtra, India
Lazreg Hadji: Department 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
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

Abstract
This study considered the experimental parameters (Nano-graphene oxide reinforced polycarbonate, GFRP) under low-velocity impact load and vibration analysis. The effect of nano-graphene oxide (NGO) on a polycarbonate-based composite was studied. Two test procedures were adopted to obtain experimental results, vibration analysis. The mechanical tests were performed on damaged and non-damaged specimens to determine the damaging effect on the composite specimens. After the test was carried out, the effect of NGO was measured and damping factors were ascertained experimentally. 0. 2 wt% NGO was determined as the optimum amount that best affected the Vibration Analysis. The experiments revealed that the composite's damping properties were increased by adding the nanoparticles to 0.25 wt% and decreased slightly for the specimens with the highest nanoparticles content. Cyclic sinus loading was applied at a frequency of 3.5 Hz. This paper study the frequency effect of 3.5khz frequency damage on mechanical results. Found that high frequency will worthlessly affect the fatigue life in NGO/polycarbonate composite. In 3.5 Hz frequency, it was chosen to decrease the heat by frequency. Transmission electron microscopy (TEM) micrographs were used to investigate the distribution of NGO on the polycarbonate matrix and revealed a homogeneous mixture of nano-composites and strong bonding between NGO and the polycarbonate which increased the damping properties and decreased vibration. Finally, experimental modal analysis was conducted after the high-velocity impact damage process to investigate the defect on the NGO polycarbonate composites.

Key Words
damping; DMTA; mechanical properties; NGO; TEM; vibration analysis

Address
Mohammad Afzali: Department of Mechanical Engineering, Kashan University, Kashan, Iran
Yasser Rostamiyan, Pooya Esmaeili: Department of Mechanical Engineering, Sari Branch, Islamic Azad University, Sari, Iran

Abstract
One of the most prevalent causes of reinforced concrete (RC) structural deterioration is chloride-induced corrosion. This paper aims to provide a comprehensive insight into the environmental effect of RC's chloride ingress process. The first step is to investigate how relative humidity, temperature, and wind influence chloride ingress into concrete. The probability of initiation time of chloride-induced corrosion is predicted using a probabilistic model that considers these aspects. Parametric analysis is conducted on several factors impacting the corrosion process, including the depth of concrete cover, surface chloride concentration, relative humidity, and temperature to expose environmental features. According to the findings, environmental factors such as surface chloride concentration, relative humidity and temperature substantially impact on the time to corrosion initiation. The long- and short-distance impacts are also examined. The meteorological data from the National Meteorological Center of China are collected and used to analyze the environmental characteristics of the chloride ingress issue for structures along China's coastline. Finally, various recommendations are made for improving durability design against chloride attacks.

Key Words
chloride; corrosion; diffusion; durability; environmental characteristic; probabilistic analysis; reinforced concrete structures

Address
Taisen Zhao, Yi Zhang, Kefei Li and Junjie Wang: Department of Civil Engineering, Tsinghua University, Beijing, China


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