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CONTENTS
Volume 43, Number 2, April25 2022
 

Abstract
Steel-reinforced concrete (SRC) L-shaped column is the vertical load-bearing member with high spatial adaptability. The seismic behavior of SRC L-shaped column is complex because of their irregular cross sections. In this study, the hysteretic performance of six steel truss reinforced concrete L-shaped columns specimens under the combined loading of compression, bending, shear, and torsion was tested. There were two parameters, i.e., the moment ratio of torsion to bending (γ) and the aspect ratio (column length-to-depth ratio (Φ). The failure process, torsion-displacement hysteresis curves, and bending-displacement hysteresis curves of specimens were obtained, and the failure patterns, hysteresis curves, rigidity degradation, ductility, and energy dissipation were analyzed. The experimental research indicates that the failure mode of the specimen changes from bending failure to bending-shear failure and finally bendingtorsion failure with the increase of γ. The torsion-displacement hysteresis curves were pinched in the middle, formed a slip platform, and the phenomenon of "load drop" occurred after the peak load. The bending-displacement hysteresis curves were plump, which shows that the bending capacity of the specimen is better than torsion capacity. The results show that the steel truss reinforced concrete L-shaped columns have good collapse resistance, and the ultimate interstory drift ratio more than that of the Chinese Code of Seismic Design of Building (GB50011-2014), which is sufficient. The average value of displacement ductility coefficient is larger than rotation angle ductility coefficient, indicating that the specimen has a better bending deformation resistance. The specimen that has a more regular section with a small Φ has better potential to bear bending moment and torsion evenly and consume more energy under a combined action.

Key Words
compression-bending-shear-torsion combined action; hysteretic behavior; L-shaped columns; quasi-static test; steel truss reinforced concrete

Address
Fan Ning:College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China

Zongping Chen:1)College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China
2)Key Laboratory of Disaster Prevention and Structure Safety of Chinese Ministry of Education, Nanning 530004, China

Ji Zhou:College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China

Dingyi Xu:College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China

Abstract
In this study, a series of cyclic loading tests were performed on viscoelastic dampers (VED) composed of viscoelastic polymer composite material and thin steel plates to observe the variation of the mechanical properties under different loading conditions. A mathematical model was developed based on the Kelvin–Voigt and Bouc–Wen models to formulate the nonlinear force-displacement relationship of the viscoelastic damper. The accuracy of the proposed mathematical model was verified using the data obtained from the tests. The mathematical model was applied to analyze a reinforced concrete framed structure retrofitted with viscoelastic dampers. Nonlinear dynamic analysis results showed that the average maximum inter-story drift ratios of the retrofitted structure met the target limit state after installing the VED. In addition, both the maximum and residual displacements were significantly reduced after the installation of the VED.

Key Words
cyclic loading test; energy dissipation devices; seismic retrofit; viscoelastic damper

Address
Mohammad Seddiq Eskandari Nasab, Seungho Chun and Jinkoo Kim:Deptartment of Global Smart City, Sungkyunkwan University, Suwon, Republic of Korea

Abstract
Most transportation departments have recognized and developed procedures to address the ever-increasing weights of trucks traveling on bridges in a service today. Transportation agencies also recognize the issues with overheight vehicles' collisions with bridges, but few stakeholders have definitive countermeasures. Bridges are becoming more vulnerable to collisions from overheight vehicles. The exact response under lateral impact force is difficult to predict. In this paper, nonlinear impact analysis shows that the degree of deformation recorded through the modeling of the unprotected vehicle-girder model provides realistic results compared to the observation from the US-61 bridge overheight vehicle impact. The predicted displacements are 0.229 m, 0.161 m, and 0.271 m in the girder bottom flange (lateral), bottom flange (vertical), and web (lateral) deformations, respectively, due to a truck traveling at 112.65 km/h. With such large deformations, the integrity of an impacted bridge becomes jeopardized, which in most cases requires closing the bridge for safety reasons and a need for rehabilitation. We proposed different sacrificial cushion systems to dissipate the energy of an overheight vehicle impact. The goal was to design and tune a suitable energy absorbing system that can protect the bridge and possibly reduce stresses in the overheight vehicle, minimizing the consequences of an impact. A material representing a Sorbothane high impact rubber was chosen and modeled in ANSYS. Out of three sacrificial schemes, a sandwich system is the best in protecting both the bridge and the overheight vehicle. The mitigation system reduced the lateral deflection in the bottom flange by 89%. The system decreased the stresses in the bridge girder and the top portion of the vehicle by 82% and 25%, respectively. The results reveal the capability of the proposed sacrificial system as an effective mitigation system.

Key Words
bridge impact; crash beam; damage mechanics; energy dissipation; early warning detection; overheight vehicle

Address
Aly Mousaad Aly and Marc A. Hoffmann:Windstorm Impact, Science and Engineering (WISE) Research Lab, Department of Civil and Environmental Engineering,
Louisiana State University, Baton Rouge, LA-70803, USA

Abstract
A Closed-form solution for dynamic response of a functionally graded (FG) nonlocal nanobeam due to action of moving harmonic load is presented in this paper. Due to analyzing in small scale, a nonlocal elasticity theory is utilized. The governing equation and boundary conditions are derived based on the Euler-Bernoulli beam theory and Hamilton's principle. The material properties vary through the thickness direction. The harmonic moving load is modeled by Delta function and the FG nanobeam is simply supported. Using the Laplace transform the dynamic response is obtained. The effect of important parameters such as excitation frequency, the velocity of the moving load, the power index law of FG material and the nonlocal parameter is analyzed. To validate, the results were compared with previous literature, which showed an excellent agreement.

Key Words
closed-form solution; dynamic response; FG Nano beam; moving harmonic load; nonlocal elasticity theory

Address
S.A.H. Hosseini:Department of Industrial, Mechanical and Aerospace Engineering, Buein Zahra Technical University, Qazvin, Iran

O. Rahmani:Smart Structures and New Advanced Materials Laboratory, Department of Mechanical Engineering, University of Zanjan, Zanjan, Iran

S. Bayat:Smart Structures and New Advanced Materials Laboratory, Department of Mechanical Engineering, University of Zanjan, Zanjan, Iran

Abstract
This paper firstly proposed high performance composite columns for cold-region infrastructures using ultra-high performance concrete (UHPC) and ultra-high strength steel (UHSS) Q960E. Then, 24 square UHPC-filled UHSS tubes (UHSTCs) at low temperatures of -80, -60, -30, and 30°C were performed under axial loads. The key influencing parameters on axial compression performance of UHSS were studied, i.e., temperature level and UHSS-tube wall thickness (t). In addition, mechanical properties of Q960E at low temperatures were also studied. Test results revealed low temperatures improved the yield/ultimate strength of Q960E. Axial compression tests on UHSTCs revealed that the dropping environmental temperature increased the compression strength and stiffness, but compromised the ductility of UHSTCs; increasing t significantly increased the strength, stiffness, and ductility of UHSTCs. This study developed numerical and theoretical models to reproduce axial compression performances of UHSTCs at low temperatures. Validations against 24 tests proved that both two methods provided reasonable simulations on axial compression performance of UHSTCs. Finally, simplified theoretical models (STMs) and modified prediction equations in AISC 360, ACI 318, and Eurocode 4 were developed to estimate the axial load capacity of UHSTCs at low temperatures.

Key Words
deformation demand; earthquake resistant design philosophy; limit states; structural damage states; levels of earthquake shaking

Address
Jia-Bao Yan:1)Key Laboratory of Coast Civil Structure Safety of Ministry of Education, Tianjin University, Tianjin 300350, China
2)School of Civil Engineering, Tianjin University, Tianjin 300350, China

Shunnian Hu:School of Civil Engineering, Tianjin University, Tianjin 300350, China

Yan-Li Luo:Architectural Engineering Institute IV, Automotive Engineering Corporation, Tianjin 300113, China

Xuchuan Lin:Architectural Engineering Institute IV, Automotive Engineering Corporation, Tianjin 300113, China

Yun-Biao Luo:1)Key Laboratory of Coast Civil Structure Safety of Ministry of Education, Tianjin University, Tianjin 300350, China 2)School of Civil Engineering, Tianjin University, Tianjin 300350, China

Lingxin Zhang:Key Laboratory of Earthquake Engineering and Engineering Vibration, Institute of Engineering Mechanics, CEA, Harbin 150080, China

Abstract
Two-dimensional stagnation point slip flow of a Casson fluid impinging normally on a flat linearly shrinking surface is considered. The modeled PDEs are changed into nonlinear ODEs through appropriate nonlinear transformations.The flow is assumed to be steady and incompressible, with external magnetic field acting on it. Similarity transformation is utilized to investigate the behavior of many parameters for heat and velocity distributions using truncation approach. The influence of buoyancy parameter, slip parameter, shrinking parameter, Casson fluid parameter on the heat profile. The effect of the magnetic parameter on the streamwise velocity profile is also investigated.

Key Words
buoyancy parameter; heat profile; magnetic parameter; steady and incompressible

Address
Faisal Al Thobiani:Marine Engineering Department, Faculty of Maritime Study, King Abdulaziz University, Jeddah, Saudi Arabia

Muzamal Hussain:Department of Mathematics, Goverment College University Faisalabad, 38000, Faisalabad, Pakistan

Mohamed Amine Khadimallah:Prince Sattam Bin Abdulaziz University, College of Engineering, Civil Engineering Department, Al-Kharj, 16273, Saudi Arabia

Emad Ghandourah:Department of Nuclear Engineering, Faculty of Engineering, King Abdulaziz University, Jeddah, Saudi Arabia

Abdulsalam Alhawsawi:Department of Nuclear Engineering, Faculty of Engineering, King Abdulaziz University, Jeddah, Saudi Arabia

Adil Alshoaibi:Department of Physics, College of Science, King Faisal University, Al-Hassa, P.O. Box, Hofuf, 31982, Saudi Arabia

Abstract
The main objective of this work is presenting a mathematical model for the concrete slab with fiber reinforced polymer (FRP) layer under the impact load. Impacts are assumed to occur normally over the top slab and the interaction between the impactor and the structure is simulated using a new equivalent three-degree-of-freedom (TDOF) spring–mass–damper (SMD) model. The structure is assumed viscoelastic based on Kelvin-Voigt model. Based on the sinusoidal shear deformation theory (SSDT), energy method and Hamilton's principle, the motion equations are derived. Applying DQM, the dynamic deflection and contact force of the structure is calculated numerically so that the effects of mass, velocity and height of impactor, boundary conditions, FRP layer, structural damping and geometrical parameters of structure are shown on the dynamic deflection and contact force of system. Results show that considering structural damping leads to lower dynamic deflection and contact force. In addition, increasing the impact velocity of impactor yields to increases in the maximum contact force and deflection while the contact duration is decreased. The result shows that the contact force and the central deflection of the structure decreases and the contact time decreases with assuming FRP layer.

Key Words
concrete slab with FRP layer; low velocity impact; numerical method; SSDT; viscoelastic

Address
Mohammad Reza Bayati:Department of Civil Engineering, Khomein Branch, Islamic Azad University, Khomein, Iran

Hamid Mazaheri:Department of Civil Engineering, Khomein Branch, Islamic Azad University, Khomein, Iran

Mahmood Rabani Bidgoli:1)Department of Civil Engineering, Khomein Branch, Islamic Azad University, Khomein, Iran
2)Department of Civil Engineering, Jasb Branch, Islamic Azad University, Jasb, Iran

Abstract
In this article, an analytical procedure is presented for static analysis of composite cylinders with the geometrically nonlinear behavior, and non-uniform thickness profiles under different loading conditions by considering moderately large deformation. The composite cylinder includes two inner and outer isotropic layers and one honeycomb core layer with adjustable Poisson's ratio. The Mirsky-Herman theory in conjunction with the von-Karman nonlinear theory is employed to extract the governing equations which are a system of nonlinear differential equations with variable coefficients. The governing equations are solved analytically using the matched asymptotic expansion (MAE) method of the perturbation technique and the effects of moderately large deformations are studied. The presented method obtains the results with fast convergence and high accuracy even in the regions near the boundaries. Highlights: · An analytical procedure based on the matched asymptotic expansion method is proposed for the static nonlinear analysis of composite cylindrical shells with a honeycomb core layer and non-uniform thickness. · The effect of moderately large deformation has been considered in the kinematic relations by assuming the nonlinear von Karman theory. · By conducting a parametric study, the effect of the honeycomb structure on the results is studied. · By adjusting the Poisson ratio, the effect of auxetic behavior on the nonlinear results is investigated

Key Words
adjustable Poisson's ratio; analytical method; composite cylinder with honeycomb core layer; moderately large deformation; nonlinear static analysis

Address
Hamidreza Eipakchi:Faculty of Mechanical and Mechatronics Engineering, Shahrood University of Technology, Shahrood, I.R. Iran

Farid Mahboubi Nasrekani: School of Information Technology, Engineering, Mathematics and Physics, The University of the South Pacific (USP), Suva, Fiji

Abstract
Recycled aggregate concrete (RAC) is rarely used in load-carrying structural members. To widen its structural application, the compressive behavior of a promising type of composite column, steel-fiber reinforced polymer (FRP) doubletube confined RAC column, has been experimentally and analytically investigated in this study. The objectives are the different performance of such columns from their counterparts using natural aggregate concrete (NAC) and the different mechanisms of the double-tube and single-tube confined concrete. The single-tube confined concrete refers to that in concrete-filled steel tubular (CFST) columns and concrete-filled FRP tubular (CFFT) columns. The test results showed that the use of recycled coarse aggregates (RCA) affected the axial load-strain response in terms of deformation capacity but such effect could be eliminated with the increasing confinement. The composite effect can be triggered by the double confinement of the steel and carbon FRP (CFRP) tubes but not by the steel and polyethylene terephthalate (PET) FRP tubes. The proposed analysis-oriented stress-strain model is capable to capture the load-deformation history of such steel-FRP double-tube confined concrete columns under axial compression.

Key Words
composite effect; FRP tube; load share; recycled aggregate concrete; steel tube; stress-strain model

Address
Ming-Xiang Xiong:Protective Structures Centre, School of Civil Engineering, Guangzhou University, Guangzhou 510006, China

Guangming Chen:State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510641, China

Yue-Ling Long:School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China

Hairui Cui:School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China

Yaoming Liu:School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China

Abstract
Buckling is one of the most critical phoneme in the design of steel structures. Lateral torsional buckling (LTB) is particularly significant for slender beams generally subjected to loading in plane. The web distortion effects on LTB are not addressed explicitly in standards for flexural design of steel I-section members. Hence, the present study is focused to predict the influence of the web distortion on the elastic (Lr) limiting lengths given in American Institute of Steel Construction (AISC) code for the lateral torsional buckling (LTB) behavior of steel beams due to no provision in the code for consideration of web distortion. For this aim, the W44x335 beam is adopted in the buckling analysis carried out by the ABAQUS finite element (FE) program since it is one of the most critical sections in terms of lateral torsional buckling (LTB). The strain results at mid-height of the web at mid-span of the beam are taken into account as the monitoring parameters. The web strain results are found to be relatively greater than the yield strain value when L/Lr is equal to 1.0. In other words, the ratio of L/Lr is estimated from the numerical analysis to be about 1.5 when the beam reaches its first yielding at mid-span of the beam at mid-height of the section. Due to the effect of web distortion, the elastic limiting length (Lr) from the numerical analysis is obtained to be considered as greater than the calculated length from the code formulation. It is suggested that the formulations of the limiting length proposed in the code can be corrected considering the influence of the web distortion. This correction can be a modification factor or a shape factor that reduces sectional slenderness for the LTB formulation in the code.

Key Words
elastic limiting length; finite element method; lateral torsional buckling (LTB); web distortion

Address
Selcuk Bas:Department of Civil Engineering, Faculty of Engineering, Architecture and Design, Bartin University, 74100 Bartin, Turkey

Abstract
Hundreds of decisions are taken at various phases and with diverse stakeholders along the building design processing, including the select of alternate components, materials, systems, assemblies, and building forms. Also, sustainability in the building sector is important since this business has a big influence on the environment and contributes significantly to socioeconomic growth specifically in Commercial Building. In terms of building sustainability, environmental issues are important issues in the early design stage, in which the principles of safety of structures, probabilistic reliability and durability are involved. A new integrated-design method that permits building analysis from a multi-performance view is regarded necessary to advance the sustainability. In this scenario, the environmental methodologies and footprint schemes for determining building sustainability are investigated using only a decision-making (DM) process on the basis of sustainable triple bottom line structure, which incorporates economic efficiency, resource conserving, and design for human adaption. The framework would enable design teams to achieve an optimal balance between social, environmental, and economic challenges, altering the path of construction practitioners' thought about the information used while appraising building projects, thereby aiding the sustainability of building industry. Finally, the technique of DM utilized in those decisions would influence the final building design, and hence the project's environmental, economic and social results.

Key Words
building design; performance-based assessment; safety; sustainability; method; sustainable construction

Address
Aifeng Wang:Architecture School, Nanyang Institute of Technology, Nanyang City Hennan Province, China

Lin Xing:Chongqing Jianzhu College, Academy of Construction Management, Chongqing 400072, China

Khidhair Jasim Mohammed:Air conditioning and Refrigeration Techniques Engineering Department, Al-Mustaqbal University College, Babylon 51001, Iraq

Anas A. Salameh:Department of Management Information Systems, College of Business Administration, Prince Sattam Bin Abdulaziz University,
165 Al-Kharj 11942, Saudi Arabia

Amin Jan:Faculty of hospitality, Tourism and Wellness, Universiti Malaysia, Kelantan, City Campus, 16100, Kota Bharu, Kelantan Malaysia

H. Elhosiny Ali:1)Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics,
Faculty of Science, King Khalid University, P.O. Box 9004, Abha, Saudi Arabia 2)Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha 61413, P.O. Box 9004, Saudi Arabia 3)Physics Department, Faculty of Science, Zagazig University, Zagazig 44519, Egypt

Islam EzzEl-Arab:Structural Engineering Department, Faculty of Engineering, Tanta University, Egypt

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