Abstract
This paper presents the behavior of geopolymer concrete beams reinforced with glass fiber reinforced polymer (GFRP) bars. In the study, ordinary Portland cement concrete and geopolymer concrete beams having GFRP bars were prepared and tested under four-point loading. The load-deflection diagrams and load capacities of the tested beams were obtained. It was observed that the tested beams exhibited good ductility and significant deflection capacity. The results showed that increasing the tension GFRP reinforcement ratio caused enhancement in the strength capacity of geopolymer concrete beams. In addition, the tested beams were analyzed to obtain the load capacity and the load-deflection responses. The theoretical load‒deflection curves and load bearing capacities have been predicted well with the test results. Parametric study has been performed to determine the influences of concrete strength, shear span to depth ratio (a/d) and reinforcement ratio on the behavior of geopolymer concrete beams longitudinally reinforced with GFRP bars. It was concluded that increasing concrete strength led to an increase in load capacity. Besides, the ultimate load increased as the reinforcement ratio increased. On the other hand, increasing a/d ratio reduced the ultimate load value of GFRP reinforced geopolymer concrete beams.
Address
Suleyman Anil Adakli, Serkan Tokgoz, Sedat Karaahmetli: Department of Civil Engineering, Adana Alparslan Turkes Science and Technology University, Adana 01250, Türkiye
Cengiz Dundar: Department of Civil Engineering, Toros University, Mersin 33340, Türkiye
Abstract
This paper investigates the influence of the torsional component of earthquake on the nonlinear structural behavior of reinforced concrete (RC) buildings. It also estimates the equivalent additional eccentricity that results from this component. For this purpose, we generate torsional accelerograms from translational ones and conduct nonlinear seismic analysis on both regular and irregular structures. The results show that the torsional component has a significant impact on the structural response, especially for irregular structures. The equivalent additional eccentricity of the cases studied was higher than 5% which is the value of accidental eccentricity suggested by many seismic codes.
Address
Abderrahmane Ouazir: Department of Civil Engineering, College of Engineering, University of Ha'il, Hail, Saudi Arabia
Asma Hadjadj: Department of Interior Design Engineering, College of Engineering, University of Ha'il, Hail, Saudi Arabia
Mansour Ouazir: Department of Civil Engineering, El.Wanchrissi University, Tissemsilt, Algeria
Mustapha Boukendakji: Department of Civil Engineering, College of Engineering, University of Ha'il, Hail, Saudi Arabia
Hatem Gasmi: Department of Civil Engineering, College of Engineering, University of Ha'il, Hail, Saudi Arabia; LR14ES03 Laboratoire d
Abstract
In this study, a finite-element surface wave simulation using an effective elastic constant (EEC) was developed to calculate the Rayleigh wave velocity change and polarization change in aluminum, steel, and concrete under uniaxial stress. Under stress, an isotropic medium behaves like an anisotropic material during the wave propagation. The EEC is an equivalent anisotropic stiffness matrix which was derived to simulate the acoustoelastic effect using classical finite-element software. The vertical and horizontal surface displacements located 8-mm from a 1-us excitation load were used to find the acoustoelastic coefficients kv and kp and compared to an analytical scheme. It was found that kv for aluminum and concrete matched within 4% of the analytical solution. The finite-element simulation showed that the Rayleigh wave arrival time for concrete and aluminum was greatly influenced by the stress level. Thus, predicting the stress level using concrete and aluminum's acoustoelastic effect is applicable.
Address
Guadalupe Leon: Department of Engineering and Physics, Doane University, 1014 Boswell Avenue, Crete, NE 68310, USA
Hung-Liang (Roger) Chen: Department of Civil and Environmental Engineering, West Virginia University, Morgantown, WV 26506, USA
Abstract
The earthquake loss assessment framework of ductile reinforced concrete (or RC) frame using componentperformance -based methodology was studied in this paper. The elasto-plastic rotation angle was used as the damage indicator of structural component, and the damage-to-loss model was proposed on the basis of the deformation indicator of structural component. Dynamic instability during incremental dynamic analysis was taken as collapse criterion, and column failure was taken as criterion that structure has to be demolished. Expected earthquake losses of low-rise, mid-rise and high-rise RC frames were discussed. The expected earthquake loss encompassed collapse loss, demolition loss and repair loss. Furthermore, component groups of RC frame were divided into structural components, nonstructural components and rugged components. The results indicate that ductile RC frame is more likely to be demolished than collapse, especially in low-rise and mid-rise RC frames. Furthermore, the less collapse margin ratio the structure has, the more demolition probability the structure will suffer under rare earthquake. The demolition share of total earthquake loss might be more prominent than repair share and collapse share in ductile RC frame.
Key Words
collapse resistant capacity; earthquake loss assessment; incremental dynamic analysis; performance-based seismic design; residual deformation; vulnerability analysis
Address
Shengfang Qiao: Guangzhou Institute of Building Science Co., Ltd., Baiyun, Guangzhou 510440, China; School of Civil Engineering and Transportation, South China University of Technology, Tianhe, Guangzhou 510641, China
Xiaolei Han: School of Civil Engineering and Transportation, South China University of Technology, Tianhe, Guangzhou 510641, China
Hesong Hu, Mengxiong Tang: Guangzhou Construction Engineering Co., Ltd., Yuexiu, Guangzhou 510000, China
Abstract
Conical shell is a common engineering structure, which is widely used in machinery, civil and construction fields. Most of them are usually exposed to external environments, temperature is an important factor affecting its performance. If the external temperature is too high, the deformation of the conical shell will occur, leading to a decrease in stability. Therefore, studying the thermal-post buckling behavior of conical shells is of great significance. This article takes graphene platelets reinforced metal foams (GPLRMF) conical shells as the research object, and uses high-order shear deformation theory (HSDT) to study the thermal post-buckling behaviors. Based on general variational principle, the governing equation of a GPLRMF conical shell is deduced, and discretized and solved by Galerkin method to obtain the critical buckling temperature and thermal post-buckling response of conical shells under various influencing factors. Finally, the effects of cone angles, GPLs distribution types, GPLs mass fraction, porosity distribution types and porosity coefficient on the thermal post-buckling behaviors of conical shells are analyzed in detail. The results show that the cone angle has a significant impact on the nonlinear thermal stability of the conical shells.
Key Words
conical shells; Galerkin method; graphene platelets; metal foams; thermal post-buckling
Address
Yin-Ping Li, Lei-Lei Gan and Gui-Lin She: College of Mechanical and Vehicle Engineering, Chongqing University, Chongqing 400044, China
Abstract
This study explores the integration of the generative AI, specifically ChatGPT (GPT-4o), into the field of structural analysis and design using the finite element method (FEM). The research is conducted in two main parts: structural analysis and structural design. For structural analysis, two scenarios are examined: one where the FEM source code is provided to ChatGPT and one where it is not. The AI's ability to understand, process, and accurately perform finite element analysis in both scenarios is evaluated. Additionally, the application of ChatGPT in structural design is investigated, including design modifications and parameter sensitivity analysis. The results demonstrate the potential of the generative AI to assist in complex engineering tasks, suggesting a future where AI significantly enhances efficiency and innovation in structural engineering. However, the study also highlights the importance of ensuring the accuracy and reliability of AI-generated results, particularly in safety-critical applications.
Key Words
artificial intelligence; ChatGPT; finite element analysis; generative AI; structural engineering
Address
Moonsu Park, Gihwan Kim: Korea Atomic Energy Research Institute, 111 Daedeok-daero, 989 Beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea
Gyeongeun Bong, Jungro Kim: Department of Mechanical Engineering, Korean Advanced Institute for Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
Abstract
The single-column pier girder bridge, due to its low engineering cost, small footprint, and aesthetic appearance, is extensively employed in urban viaducts and interchange ramps. However, its structural design makes it susceptible to eccentric loads, flexural-torsional coupling effects, and centrifugal forces, among others. To evaluate its anti-overturning performance reasonably, it is crucial to determine the reaction force of the support for the single-column pier girder bridge. However, due to the interaction between vehicle and bridge and the complexity of vibration modes, it poses a significant challenge to analyze the theory or finite element method of single-column pier girder bridges. The unit load bearing reaction coefficient method is proposed in this study to facilitate the static analysis. Numerous parameter analyses have been conducted to account for the dynamic amplification effect. The results of these analyses reveal that the dynamic amplification factor is independent of road surface roughness but is influenced by factors such as the position of the support. Based on parameter analysis, the formula of the dynamic amplification factor is derived by fitting.
Key Words
anti-overturning; dynamic amplification factor; single-column pier girder bridge; support reaction; vehiclebridge interaction
Address
Liang Cao, Hailei Zhou and Zhichao Ren: College of Civil Engineering, Hunan University, Changsha 410082, China; Key Laboratory for Damage Diagnosis of Engineering Structures of Hunan Province, Hunan University, Changsha 410082, China
Abstract
Nanotechnology has emerged as a promising avenue for enhancing musical structures. In this study, we analyze the static behavior of laser harp (i.e., electronic musical instrument) reinforced with Zinc Oxide (ZnO) nanoparticles. Leveraging the piezoelectric properties of ZnO nanoparticles, the structure is subjected to an electric field for intelligent control. The electronic musical structure is situated in a foundation with vertical springs and shear modulus constants. We employ the exponential Shear Deformation Beam Theory (ESDBT) to mathematically model the structure. A micro-electro-mechanical model is employed to
determine the equivalent properties of the system. By utilizing nonlinear stress-strain relations, energy methods, and Hamilton's principle, we derive the motion equations. The buckling load of the electronic musical beam is calculated using the Difference Quadrature Method (DQM). The primary objective of this study is to present a mathematical model for electronic musical beams and determining the buckling load of the structure and to investigate the influence of nanotechnology and electric fields on its buckling behavior. The buckling is the case when the structure becomes deforms and unstable. Our findings reveal that the application of negative external voltage to the electronic musical structure increases both the stiffness and the buckling load of the musical system. Furthermore, reinforcing the electronic musical structure with ZnO nanoparticles results in an increased buckling load. Notably, the maximum enhancement in the 28-day compressive and tensile strengths of samples containing zinc oxide nanoparticles compared to the control sample resulting in increases of 18.70% and 3.77%, respectively.
Key Words
electronic musical structures; experimental and theoretical analysis; external voltage; model; ZnO nanoparticles
Address
Jing Han: Elementary Education College, Zaozhuang University, 277160, Shandong Province, China
Maryam Shokravi: Energy Institute of Higher Education, Mehrab High School, Saveh, Iran
F. Ming: College of Shipbuilding Engineering, Harbin Engineering University, Harbin, China
