Abstract
This paper presents an experimental investigation on the effects of shear span ratio, stirrup ratio, number of annular
carbon fiber reinforced plastics (CFRP) and longitudinal CFRP sheets on the shear stiffness of polyvinyl chloride (PVC)-CFRP
confined reinforced concrete beams (PCRCBs). A total of 11 PCRCBs with a cylindrical cross-section and a length of 1500 mm
were designed and fabricated for four-point bending tests. The experimental results indicated that the stiffness and ultimate
bearing capacity of specimens decreased with the decrease of shear span ratio or the increase of shear span ratio. Conversely, an
increase in the number of CFRP strip layers and CFRP sheets led to enhancements in the initial stiffness, the stiffness during the
stabilization phase, and the ultimate bearing capacity. Additionally, this increase in CFRP layers slowed down the rate of
stiffness degradation. Based on the experimental results, formulas for calculating the short-term stiffness and predicting the
deflection of PCRCB were derived by combining the curvature method. The accuracy of the formula was verified to be
consistent with the experimental data.
Address
Feng Yu:Dept. of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan, 243032, China
Xing Chen:Dept. of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan, 243032, China
Honglei Xie:Dept. of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan, 243032, China
Shisi Wang:Dept. of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan, 243032, China
Shijiang Zhang:Engineering Research Center of Anhui Metallurgical Solid Waste Green Construction, Anhui University of Technology, Ma'anshan, 243032, China
Abstract
The residual strength evaluation under a quasi-static loading system after a fire event in an electrical cabinet of an
NPP is the main concern of this study. The capacity reduction, ductility displacement change, local joint behavior estimation,
maximum displacement changes with corresponding base shear show the residual performance. The full-scale three-dimensional
finite element model (FEM) is generated by considering the constitutive material model to adopt the fire event. Modal parameter
estimation is taken into account to capture the dynamic property of the cabinet by the shake table test for comparing the
fundamental frequencies, which leads to the calibration of the FEM. The quasi-s residual strength; fire-damaged FEM;
capacity degradation; displacement ductility; local joint behavior tatic load has been applied under the fire event along with
the gravity load to get the reduction pattern of the structural performance. The results analysis shows that the elevated
temperature due to fire has a significant impact on the cabinet, on which the capacity reduction expresses an abrupt change after
a specific temperature. This is also notified in the displacement ductility, joint behavior as well as maximum displacement
change.
Key Words
capacity degradation; displacement ductility; fire-damaged FEM; local joint behavior; residual strength
Address
Md M. Rahman:Department of Civil Engineering, Pabna University of Science and Technology, Rajapur, Pabna 6600, Bangladesh
Tahmina T. Nahar:Department of Civil Engineering, Pabna University of Science and Technology, Rajapur, Pabna 6600, Bangladesh
Dookie Kim:Department of Civil Engineering and Environmental Engineering, Kongju National University, 1223-24 Cheonan-daero,
Seobuk-gu, Cheonan, Chungcheongnam-do 31080, Republic of Korea
Abstract
Composite bushing is composed of the outer sleeve and metal conductor, which has a high seismic vulnerability. A
simplified theoretical model is established by the free-body strategy based on equilibrium equations, and its effectiveness is
verified by a shaking table test and finite element analysis of full-scale ultra-high voltage (UHV) electrical equipment. The
interaction mechanism between the outer sleeve and conductor is revealed, seismic design parameters of relative displacement
reduction are analyzed and the design methods are given. The results show that frequency drift occurs in the process of high
amplitude excitation due to the nonlinear mechanical properties of the composite bushing. The acceleration power spectrum of
high modes is several times greater than that of the fundamental mode, as the peak ground acceleration (PGA) reaches 0.5g. The
regularity of relative displacement along the height direction between the outer sleeve and conductor shows an asymmetrical
distribution on both sides of the midpoint of the conductor, and the maximum value occurs between the gravity center and
bottom flange. For engineering design of relative displacement reduction, section characteristic of metal conductors is the crucial
factor, and subfactors are flexural stiffness of the conductor base and outer sleeve, respectively. The seismic response of
composite bushing can be obtained by the simplified theoretical model considering coupling effects, and great concern should
arise in the influence of high modes.
Key Words
analytical method; composite bushing; coupled system; seismic response; shaking table test
Address
Gaoyang Shi:College of Civil Engineering, Tongji University Shanghai 200092, China
Qiang Xie:College of Civil Engineering, Tongji University Shanghai 200092, China
Xiuli Zhang:College of Water Conservancy and Civil Engineering, South China Agricultural University, Guangzhou 510640, China
Abstract
The proposed model introduces a novel approach to predicting stiffness and Poisson's ratio degradation in metal
ceramic sandwich plates, specifically under hygro-thermo-mechanical loadings. Unlike previous models such as the Equivalent
Constraint Model (ECM), this model incorporates an inter-laminar adhesive layer to transmit normal and shear stresses between
the ceramic and metallic layers, significantly enhancing its accuracy in environmental stress simulation. By extending the shear
lag model to include temperature and humidity effects, this model provides a more precise prediction of mechanical response
under extreme operational conditions. Validation against experimental data further establishes the model's reliability, showing a
substantial improvement in predictive capability. The Analysis reveals that both stiffness and Poisson's ratio degrade
progressively with increasing crack density, temperature, and concentration, with the extent of degradation varying across metal
content. Validated against experimental data, this model advances scientific understanding of metal-ceramic composite
performance and provides a practical, accurate tool for designing resilient composites in demanding sectors such as aerospace
and automotive, where environmental resilience is critical.
Key Words
hygro-thermo-mechanical; metal ceramic; poisson's ratio; shear-lag; stiffness; transverse cracking
Address
Mohamed Khodjet-Kesba:Aeronautical Sciences Laboratory, Institute of Aeronautics, and Space Studies, University of Blida 1, BP 270 Blida 09000, Algeria
Zineb Mouloudj:Aeronautical Sciences Laboratory, Institute of Aeronautics, and Space Studies, University of Blida 1, BP 270 Blida 09000, Algeria
Billel Boukert:Aeronautical Sciences Laboratory, Institute of Aeronautics, and Space Studies, University of Blida 1, BP 270 Blida 09000, Algeria
Abstract
This study investigates the arch mechanism of anti-collapse in steel modular buildings with flat steel load-bearing
walls when two adjacent modules are lost. It considers the impact of module length, module height, wall thickness, module
beam dimension, and wall opening on the collapse performance of steel modular buildings. A practical design-based model is
developed to predict the collapse resistance of steel modular buildings due to arch mechanism, taking into account various
structural parameters. Findings indicate that an increase in module height enhances the anti-collapse resistance of steel modular
buildings and reduces the displacement at the end of the arch mechanism. Conversely, an increase in module length decreases
the anti-collapse resistance while increasing the displacement at the end of the arch mechanism. Both the anti-collapse resistance
and displacement are improved with increases in wall panel thickness or beam section dimension. However, increases in wall
opening height and length reduce both collapse resistance and displacement, with wall opening height having a more
pronounced effect on collapse resistance than opening length. The regression results indicate that the ratio of the resistance of
steel modular buildings due to arch mechanism to the yield resistance can be expressed by a combined power function of the
wall height-to-thickness ratio, wall length-to-thickness ratio, and beam span-to-depth ratio. The detrimental effect due to wall
opening to the resistance of steel modular buildings at arch mechanism stage can be quantified also by power functions of
opening location and opening size.
Abstract
This study aims to evaluate the post-earthquake damage degree of modular precast steel reinforced concrete
column-to-steel beam composite joints (MPCJs). The seismic performance level (SPL) and damage index (DI) of MPCJs were
classified and quantified using mathematical statistical methods. Based on the analysis of a two-parameter seismic damage
model (SDM) incorporating deformation and cumulative energy dissipation (DCED), an SDM suitable for characterizing the
seismic performance evolution of MPCJs was established through numerical regression analysis. Subsequently, the modified
SDM was utilized to investigate the influence of various parameters on joint damage. The results demonstrate that the SPL of
MPCJs can be categorized into five distinct levels. A two-parameter SDM considering DCED was developed based on the
Banon model. The accuracy of the proposed SDM and the rationality of the seismic performance classification criteria were
effectively validated by comparing the calculated results of the SDM with experimental data and finite element analysis. The
proposed DI model provides a reliable representation of the seismic damage behavior of MPCJs.
Key Words
assembled steel-concrete composite joints; damage model; deformation; hysteretic energy consumption;
seismic performance level
Address
Nan Jiang:Qingdao Open University, Qingdao, China
Hao Li:School of Civil Engineering, Qingdao University of Technology, Qingdao, China
Chenglong Wu:1)School of Civil Engineering, Qingdao University of Technology, Qingdao, China
2)Graduate School of Science and Engineering, Saitama University, Saitama, Japan
Zhen Zhu:School of Civil Engineering, Qingdao University of Technology, Qingdao, China
Hao Yu:China Construction Engineering Group Shandong Co., Ltd, Qingdao 266000, P.R. China
Ning Ning:School of Civil Engineering, Qingdao University of Technology, Qingdao, China
Caiwei Liu:School of Civil Engineering, Qingdao University of Technology, Qingdao, China
Zhiyu Pan:The Fourth Construct on Co., Ltd of China Construction Eighth Engineering Division, Qingdao, China
Zhonghua Wang:The Fourth Construct on Co., Ltd of China Construction Eighth Engineering Division, Qingdao, China
