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CONTENTS
Volume 24, Number 1, January 2023
 


Abstract
A model for calculating structure interacted mechanics is proposed. A structural interaction model and controller design based on tuned mass damping (TMD) was developed to control the induced vibration. A key point is to introduce a new analytical model to evaluate the properties of the TMD that recognizes the motion-dependent nonlinear response observed in the simulations. Aiming at the problem of increased current harmonics and low efficiency of permanent magnet synchronous motors for electric vehicles due to dead time effect, a dead time compensation method based on neural network filter and current polarity detection is proposed. Firstly, the DC components and the higher harmonic components of the motor currents are obtained by virtue of what the neural network filters and the extracted harmonic currents are adjusted to the required compensation voltages by virtue of what the neural network filters. Then, the extracted DC components are used for current polarity dead time compensation control to avert the false compensation when currents approach zero. The neural network filter method extracts the required compensation voltages from the speed component and the current polarity detection compensation method obtains the required compensation voltages by discriminating the current polarity. The combination of the two methods can more precisely compensate the dead time effect of the control system to improve the control performance. Furthermore, based on the relaxed method, the intelligent approach of stability criterion can be regulated appropriately and the artificial TMD was found to be effective in reducing cross-wind vibrations.

Key Words
intelligent control function; stochastic mechanics fuzzy systems; structural interacted mechanic

Address
Z.Y. Chen, Ruei-Yuan Wang, Yahui Meng: School of Science, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China
Timothy Chen: California Institute of Technology, Pasadena, CA 91125, USA

Abstract
"Performance-based design (PBD)" is based on designing a structure with choosing a performance target under design criteria to increase the structure's resistance against earthquake effect. The plastic hinge formation is determined as one of the fundamental data in finite elements nonlinear analysis to distinguish the condition of the structure where more significant potential damage could occur. If the number of plastic hinges in the structure is increased, the total horizontal load capability of the structure is increased, also. Theoretically, when the number of plastic hinges of the plane frame structure reaches "the degree of hyperstaticity plus one", the structure will reach the capability of the largest ultimate horizontal load. As the number of plastic hinges to be formed in the structure increases towards the theoretical plastic hinge number (TPHN), the total horizontal load capability of the structure increases, proportionally. In the previous studies of the authors, the features of examining the new performance criteria were revealed and it was formulated as follows "Increase the total number of plastic hinges to be formed in the structure to the number of theoretical plastic hinges as much as possible and keep the structure below its targeted performance with related codes". With this new performance criterion, it has been shown that the total lateral load capability of the building is higher than the total lateral load capability obtained with the traditional PBD method by the FEMA 440 and FEMA 356 design guides. In this study, PBD analysis results of structures with frame carrier systems are presented in the light of the Turkey Building Earthquake Code 2019. As a result of this study, it has been shown that the load capability of the structure in the examples of structures with frame carrier system increases by using this new performance criterion presented, compared to the results of the examination with the traditional PBD method in TBEC 2019.

Key Words
finite element method; load bearing capacity; performance-based design (PBD); plastic hinge; pushover analysis

Address
Azer A. Kasimzade: Department of Civil Engineering, Ondokuz Mayis University, Samsun, Atakum 55270, Turkey
Emin Nematli: Graduate School of Natural and Applied Sciences, Ondokuz Mayis University, Samsun, Atakum 55270, Turkey
Mehmet Kuruoglu: Department of Civil Engineering, Dokuz Eylul University, Izmir, Buca 35390, Turkey

Abstract
Structural vibrations generated by earthquakes and wind loads can be controlled by varying the structural parameters such as mass, stiffness, damping ratio, and geometry and providing a certain amount of passive or active reaction forces. A Double-Tuned Mass Dampers (DTMDs) system, which is simple and more effective than the conventional single tuned mass damper (TMD) system for vibration mitigation is presented. Two TMDs tuned to the first two natural frequencies were used to control vibrations. Experimental investigations were carried out on a three degrees-of-freedom frame model to investigate the effectiveness of DTMDs systems in controlling displacements, accelerations, and base shear. Numerical models were developed and validated against the experimental results. The validation showed a good match between the experimental and numerical results. The validated model was employed to investigate the behavior of a five degrees-of-freedom shear building structure, wherein mass dampers with different mass ratios were considered. The effectiveness of the DTMDs system was investigated for harmonic, seismic, and white noise base excitations. The proposed system was capable of significantly reducing the story displacements, accelerations, and base shears at the first and second natural frequencies, as compared to conventional single TMD.

Key Words
DTMDs; harmonic; seismic; single TMD; vibration control; white noise

Address
Mohammed Fasil: Civil and Environmental Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
R. Sajeeb: Department of Civil Engineering, TKM College of Engineering, Kollam, Kerala, 691005, India
Nizar A. Assi: Department of Civil and Environmental Engineering, Birzeit University, PO Box 14, Birzeit, West Bank, Palestine
Muhammad K. Rahman: Interdisciplinary Research Center for Construction and Building Materials, KFUPM, Dhahran 31261, Saudi Arabia

Abstract
Türkiye has made significant changes and updates in both seismic risk maps and design codes over time, as have other countries with high seismic risk. In this study, the last two seismic design codes and risk maps were compared for the Aegean Region (Western Türkiye) where the earthquake risk has once again emerged with the 2020 Izmir Earthquake (Mw=6.9). In this study, information about the seismicity of the Aegean Region was given. The seismic parameters for all provinces in the region were compared with the last two earthquake risk maps. The spectral acceleration coefficients of all provinces have increased and differentiated with the current seismic hazard map as a result of the design spectra used on a regional basis have been replaced by the geographical location-specific design spectra. In addition, section damage limits were obtained for all provinces within the scope of the last two seismic design codes. Structural analyses for a sample reinforcedconcrete building were made separately for each province using pushover analysis. The deformations in the cross-sections were compared with the limit states corresponding to the damage levels specified in the last two seismic design codes for the region. Target displacement requests for all provinces have decreased with the current code. The differentiation of geographical location-specific design spectra both in the last two seismic design code and between provinces has caused changes in section damages and building performance levels. The main aim of this study is to obtain and compare both seismic and structural analysis results for all provinces in the Aegean Region (Western Türkiye).

Key Words
Aegean Region; design spectra; pushover; seismic risk; western Türkiye

Address
Ercan Işik: Department of Civil Engineering, Bitlis Eren University, TR-13000, Bitlis, Turkey
Hakan Ulutaş: Department of Civil Engineering, Burdur Mehmet Akif University, TR-15000, Burdur, Turkey
Aydin Büyüksaraç: Çan Vocational School, Çanakkale Onsekizmart University, TR-17400, Çanakkale, Türkiye

Abstract
Earth fissures with several kilometers will inevitably approach or cross the metro line, significantly threatening the safety of the underground structure in the earth fissure site. However, the influence of the earth fissure site's amplification effect on the metro station's dynamic response is still unclear. A representative earth fissure in Xi'an was taken as an example to establish a numerical model of a metro station in the earth fissure site. The dynamic response characteristics of the metro stations at different distances from the earth fissure under various seismic waves were calculated. The results show that the existence of the earth fissure significantly amplifies the dynamic response of the nearby underground structures. The responses of the axial force, shear force, bending moment, normal stress, horizontal displacement, inter-story drift, and relative slip of the metro station were all amplified within a specific influence range. The amplification effect increases with the seismic wave intensity. The amplification effect caused by the earth fissure has relatively weak impacts on the axial shear, shear force, bending movement, normal stress, and horizontal movement; slightly larger impacts on the inter-story drift and acceleration; and a significant impact on the relative slip. The influence ranges of the axial force and normal stress are approximately 20 m. The influence ranges of the acceleration and inter-story drift can reach 30 m. Therefore, the seismic fortification level of the underground structure in the earth fissure site needs to be improved.

Key Words
amplification effect; dynamic response; earth fissure; metro station; seismic fortification

Address
Jiang Chang: School of Geological Engineering and Geomatics, Chang'an University, Xi'an 710054, China
Yahong Deng: Key Laboratory of Mine Geological Hazards Mechanism and Control, Ministry of Natural Resources, Xi'an 710054, China
Huandong Mu: Institute of Geotechnical Engineering, Xi'an University of Technology, Xi'an 710048, China

Abstract
A simplified analytical solution for seismic response of tunnel cross section in horizontally layered ground subjected to oblique incidence of SH wave is deduced in this paper. The proposed analytical solution consists of two main steps: free-field response in layered field and tunnel response. The free field responses of the layered ground are obtained by one-dimensional finite element method in time domain. The tunnel lining is treated as a thick-wall cylinder to calculate the tunnel response, which subject to free field stress. The analytical solutions are verified by comparing with the dynamic numerical results of twodimensional ground-lining interaction analysis under earthquake in some common situations, which have a good agreement. Then, the appropriate range of the proposed analytical solution is analyzed, considering the height of the layered ground, the wavelength and incident angle of SH wave. Finally, by using the analytical solutions, the effects of the ground material, burial depth of the tunnel, and lining thickness and the slippage effect at the ground-lining interface on the seismic response of tunnels are investigated. The proposed solution could serve as a useful tool for seismic analysis and design of tunnels in layered ground.

Key Words
analytical solution; layered ground; oblique incidence; tunnel

Address
Huifang Li, Weizhang Liao and Chao Ma: School of Civil and Transportation Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China
Mi Zhao: Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education, Beijing University of Technology, Beijing 100124, China
Jingqi Huang: Beijing Key Laboratory of Urban Underground Space Engineering, School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, 100083, China


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