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CONTENTS | |
Volume 42, Number 2, January25 2022 |
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- Composite components damage tracking and dynamic structural behaviour with AI algorithm Z.Y. Chen, Sheng-Hsiang Peng, Yahui Meng, Ruei-Yuan Wang, Qiuli Fu and Timothy Chen
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Abstract; Full Text (2048K) . | pages 151-159. | DOI: 10.12989/scs.2022.42.2.151 |
Abstract
This study discusses a hypothetical method for tracking the propagation damage of Carbon Reinforced Fiber Plastic
(CRFP) components underneath vibration fatigue. The High Cycle Fatigue (HCF) behavior of composite materials was
generally not as severe as this of admixture alloys. Each fissure initiation in metal alloys may quickly lead to the opposite. The
HCF behavior of composite materials is usually an extended state of continuous degradation between resin and fibers. The
increase is that any layer-to-layer contact conditions during delamination opening will cause a dynamic complex response,
which may be non-linear and dependent on temperature. Usually resulted from major deformations, it could be properly
surveyed by a non-contact investigation system. Here, this article discusses the scanning laser application of that vibrometer to
track the propagation damage of CRFP components underneath fatigue vibration loading. Thus, the study purpose is to
demonstrate that the investigation method can implement systematically a series of hypothetical means and dynamic
characteristics. The application of the relaxation method based on numerical simulation in the Artificial Intelligence (AI)
Evolved Bat (EB) strategy to reduce the dynamic response is proved by numerical simulation. Thermal imaging cameras are
also measurement parts of the chain and provide information in qualitative about the temperature location of the evolution and
hot spots of damage.
Key Words
artificial intelligence; CRFP components; evolved bat; propagation damage; scanning LDV
Address
Z.Y. Chen: Guangdong University of Petrochem Technol, Sch Sci, Maoming 525000, China
Sheng-Hsiang Peng: Department of Civil and Environmental Engineering, University of California, Irvine, CA, 92697, U.S.A.
Yahui Meng: Guangdong University of Petrochem Technol, Sch Sci, Maoming 525000, China
Ruei-Yuan Wang: Guangdong University of Petrochem Technol, Sch Sci, Maoming 525000, China
Qiuli Fu: School of Computer Sci, Guangdong University of Petrochem Technol, Maoming 525000, China
Timothy Chen: 4Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, 91125, U.S.A.
- Studies on CFST column to steel beam joints using endplates and long bolts under central column removal Shan Gao, Bo Yang, Lanhui Guo, Man Xu and Feng Fu
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Abstract; Full Text (2541K) . | pages 161-172. | DOI: 10.12989/scs.2022.42.2.161 |
Abstract
In this paper, four specimens of CFST column joints with endplates and long bolts are tested in the scenario of
progressive collapse. Flush endplate and extended endplate are both adopted in this study. The experimental results show that
increasing the thickness of the endplate could improve the behavior of the joint, but delay the mobilization of catenary action.
The thickness of the endplate should not be relatively thick in comparison to the diameter of the bolts, otherwise catenary action
would not be mobilized or work effectively. Effective bending deformation of the endplate could help the formation and
development of catenary action in the joints. The performance of flexural action in the joint would affect the formation of
catenary action in the joint. Extra middle-row bolts set at the endplates and structural components set below the bottom beam
flange should be used to enhance the robustness of joints. A special weld access hole between beam and endplate should be
adopted to mitigate the chain damage potential of welds. It is suggested that the structural components of joints should be
independent of each other to enhance the robustness of joints. Based on the component method, a formula calculating the
stiffness coefficient of preloaded long bolts was proposed whose results matched well with the experimental results.
Key Words
catenary action; CFST; component method; endplate; long bolts; progressive collapse
Address
Shan Gao:1)Shaanxi Key Laboratory of safety and durability of concrete structures, Xijing University, Xi'an University
2) School of Civil Engineering, Harbin Institute of Technology, Harbin, China
3)School of Civil Engineering, Chongqing University, Chongqing, China
Bo Yang: School of Civil Engineering, Chongqing University, Chongqing, China
Lanhui Guo: School of Civil Engineering, Harbin Institute of Technology, Harbin, China
Feng Fu: School of Mathematics, Computer Science & Engineering, University of London, London, U.K.
- Axially-loaded multiplanar tubular KTX-joints: numerical analysis Chenhui Zhang, Bo Zou and Guotao Yang
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Abstract; Full Text (2569K) . | pages 173-190. | DOI: 10.12989/scs.2022.42.2.173 |
Abstract
With the development of spatial structures, the joints are becoming more and more complex to connect tubular
members of spatial structures. In this study, an approach is proposed to establish high-efficiency finite element model of
multiplanar KTX-joint with the weld geometries accurately simulated. Ultimate bearing capacity the KTX-joint is determined
by the criterion of deformation limit and failure mechanism of chord wall buckling is studied. Size effect of fillet weld on the
joint ultimate bearing capacity is preliminarily investigated. Based on the validated finite element model, a parametric study is
performed to investigate the effects of geometric and loading parameters of KT-plane brace members on ultimate bearing
capacity of the KTX-joint. The effect mechanism is revealed and several design suggestions are proposed. Several simple
reinforcement methods are adopted to constrain the chord wall buckling. It is concluded that the finite element model established
by proposed approach is capable of simulating static behaviors of multiplanar KTX-joint; chord wall buckling with large
indentation is the typical failure mode of multiplanar KTX-joint, which also increases chord wall displacements in the axis
directions of brace members in orthogonal plane; ultimate bearing capacity of the KTX-joint increases approximately linearly
with the increase of fillet weld size within the allowed range; the effect mechanism of geometric and loading parameters are
revealed by the assumption of restraint region and interaction between adjacent KT-plane brace members; relatively large
diameter ratio, small overlapping ratio and small included angle are suggested for the KTX-joint to achieve larger ultimate
bearing capacity; the adopted simple reinforcement methods can effectively constrain the chord wall buckling with the design of
KTX-joint converted into design of uniplanar KT-joint.
Key Words
failure mechanism; geometric and loading effects; multiplanar KTX-joint; parametric study; preliminary
reinforcement; ultimate bearing capacity
Address
Chenhui Zhang: School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
Bo Zou: College of Civil Engineering, Tongji University, Shanghai 200092, China
Guotao Yang: School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
- Experimental investigation of natural bond behavior in circular CFTs Morteza Naghipour, Aidin Khalili, Seyed Mohammad Reza Hasani and Mahdi Nematzadeh
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Abstract; Full Text (2492K) . | pages 191-207. | DOI: 10.12989/scs.2022.42.2.191 |
Abstract
Undoubtedly, the employment of direct bond interaction between steel and concrete is preceding the other
mechanisms because of its ease of construction. However, the large scatter in the experimental data about the issue has hindered
the efforts to characterize bond strength. In the following research, the direct bond interaction and bond-slip behavior of CFTs
with circular cross-section were examined through repeated load-reversed push-out tests until four cycles of loading. The
influence of different parameters including the diameter of the tube and the use of shear tabs were assessed. Moreover, the
utilization of expansive concrete and external spirals was proposed and tested as ways of improving bond strength. According to
the results section dimensions, tube slenderness, shrinkage potential of concrete, interface roughness and confinement are key
factors in a natural bond. Larger diameters will lead to a considerable drop in bond strength. The use of shear tabs by their
associated bending moments increases the bond stress up to eight times. Furthermore, employment of external spirals and
expansive concrete have a sensible effect on enhancing bonds. Macro-locking was also found to be the main component in
achieving bond strength.
Key Words
concrete-filled steel tube (CFT); load transfer; bond strength; push-out test; macro-locking
Address
Morteza Naghipour: Department of Civil Engineering, Babol Noshirvani University of Technology, Babol, Iran
Aidin Khalili: Department of Civil Engineering, Babol Noshirvani University of Technology, Babol, Iran
Seyed Mohammad Reza Hasani: Department of Civil Engineering, Babol Noshirvani University of Technology, Babol, Iran
Mahdi Nematzadeh: Department of Civil Engineering, Faculty of Engineering and Technology, University of Mazandaran, Babolsar, Iran
- Seismic response evaluation of fixed jacket-type offshore structures by random vibration analysis Shehata E. Abdel Raheem, Elsayed M. Abdel Aal, Aly G.A. AbdelShafy and Mohamed F.M. Fahmy
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Abstract; Full Text (2635K) . | pages 209-219. | DOI: 10.12989/scs.2022.42.2.209 |
Abstract
Offshore platforms in seismically active areas must be designed to survive in the face of intense earthquakes without
a global structural collapse. This paper scrutinizes the seismic performance of a newly designed and established jacket type
offshore platform situated in the entrance of the Gulf of Suez region based on the API-RP2A normalized response spectra during
seismic events. A nonlinear finite element model of a typical jacket type offshore platform is constructed taking into
consideration the effect of structure-soil-interaction. Soil properties at the site were manipulated to generate the pile lateral soil
properties in the form of load deflection curves, based on API-RP2A recommendations. Dynamic characteristics of the offshore
platform, the response function, output power spectral density and transfer functions for different elements of the platform are
discussed. The joints deflection and acceleration responses demands are presented. It is generally concluded that consideration of
the interaction between structure, piles and soil leads to higher deflections and less stresses in platform elements due to soil
elasticity, nonlinearity, and damping and leads to a more realistic platform design. The earthquake-based analysis for offshore
platform structure is essential for the safe design and operation of offshore platforms.
Key Words
offshore platform; random vibration; response function; response spectrum analysis; seismic performance
Address
Shehata E. Abdel Raheem: Civil Engineering Dept., Faculty of Engineering, Assuit University, Assiut71516, Egypt
Elsayed M. Abdel Aal: Offshore Projects Engineer, Egypt Gas Company, Egypt
Aly G.A. AbdelShafy: Civil Engineering Dept., Faculty of Engineering, Assuit University, Assiut71516, Egypt
Mohamed F.M. Fahmy: Civil Engineering Dept., Faculty of Engineering, Assuit University, Assiut71516, Egypt
- Elastic stiffness of perfobond connections in composite structures Xi Qin and Guotao Yang
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Abstract; Full Text (4102K) . | pages 221-241. | DOI: 10.12989/scs.2022.42.2.221 |
Abstract
Perfobond rib connectors are widely used in composite structures to achieve the composite action between the steel
and the concrete, and empirical expressions for their strength and secant stiffness have been obtained by numerical simulations
or push-out tests. Since perfobond connections are generally in an elastic state in the service process and the structural analysis
are always based on the elastic properties of the members, the secant stiffness is not applicable for the normal structural analysis.
However, the tangent stiffness of perfobond connections has not been introduced in previous studies. Moreover, the perfobond
connections are bearing tension and shear force simultaneously when the composite beams subjected to torque or local loads, but
the current studies fail to arrive at the elastic stiffness considering the combined effects. To resolve these discrepancies, this
paper investigates the initial elastic stiffness of perfobond connections under combined forces. The calculation method for the
elastic stiffness of perfobond connections is analyzed, and the contributions of the perfobond rib, the perforating rebar and the
concrete dowel are investigated. A finite element method was verified with a high value of correlation for the test results.
Afterwards, parametric studies are carried out using the reliable finite element analysis to explore the trends of several factors.
Empirical equations for predicting the initial elastic stiffness of perfobond connections are proposed by the numerical regression
of the data extracted by parametric studies. The equations agree well with finite element analysis and test results, which indicates
that the proposed empirical equations reflect a high accuracy for predicting the initial elastic stiffness of perfobond connections.
Key Words
composite structure; design equation; finite element analysis; initial elastic stiffness; perfobond connector
Address
Xi Qin: School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
Guotao Yang: School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
- A novel coupled finite element method for hydroelastic analysis of FG-CNTRC floating plates under moving loads Vu X. Nguyen, Qui X. Lieu, Tuan A. Le, Thao D. Nguyen, Takayuki Suzuki and Van Hai Luong
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Abstract; Full Text (2336K) . | pages 243-256. | DOI: 10.12989/scs.2022.42.2.243 |
Abstract
A coupled finite element method (FEM)-boundary element method (BEM) for analyzing the hydroelastic response
of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) floating plates under moving loads is firstly
introduced in this article. For that aim, the plate displacement field is described utilizing a generalized shear deformation theory
(GSDT)-based FEM, meanwhile the linear water-wave theory (LWWT)-relied BEM is employed for the fluid hydrodynamic
modeling. Both computational domains of the plate and fluid are coincidentally discretized into 4-node Hermite elements.
Accordingly, the C1−continuous plate element model can be simply captured owing to the inherent feature of third-order
Hermite polynomials. In addition, this model is also completely free from shear correction factors, although the shear
deformation effects are still taken into account. While the fluid BEM can easily handle the free surface with a lower
computational effort due to its boundary integral performance. Material properties through the plate thickness follow four
specific CNT distributions. Outcomes gained by the present FEM-BEM are compared with those of previously released papers
including analytical solutions and experimental data to validate its reliability. In addition, the influences of CNT volume fraction,
different CNT configurations, water depth, and load speed on the hydroelastic behavior of FG-CNTRC plates are also examined.
Key Words
boundary finite element (BEM); finite element method (FEM); functionally graded carbon nanotubereinforced composite (FG-CNTRC); hydroelastic analysis; moving loads
Address
Vu X. Nguyen:1) Faculty of Civil Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet
Street, Ward 14, District 10, Ho Chi Minh City, Vietnam
2) Vietnam National University Ho Chi Minh City (VNU-HCM), Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Vietnam
Qui X. Lieu: 1) Faculty of Civil Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet
Street, Ward 14, District 10, Ho Chi Minh City, Vietnam
2) Vietnam National University Ho Chi Minh City (VNU-HCM), Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Vietnam
Tuan A. Le: 1) Faculty of Civil Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet
Street, Ward 14, District 10, Ho Chi Minh City, Vietnam
2) Vietnam National University Ho Chi Minh City (VNU-HCM), Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Vietnam
Thao D. Nguyen: 1) Faculty of Civil Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet
Street, Ward 14, District 10, Ho Chi Minh City, Vietnam
2) Vietnam National University Ho Chi Minh City (VNU-HCM), Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Vietnam
Takayuki Suzuki: Department of Civil Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogayaku, Yokohama 240-8501, Japan
Van Hai Luong: 1) Faculty of Civil Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet
Street, Ward 14, District 10, Ho Chi Minh City, Vietnam
2) Vietnam National University Ho Chi Minh City (VNU-HCM), Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Vietnam
- Analysis of key elements of single-layer dome structures against progressive collapse Qian Zhang, Wenxing Huang, Yixiang Xu, Jianguo Cai, Fang Wang and Jian Feng
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Abstract; Full Text (2128K) . | pages 257-264. | DOI: 10.12989/scs.2022.42.2.257 |
Abstract
The analysis of the progressive collapse resistance of structures is a well-known issue among structural engineers.
Large-span reticulated dome structures are commonly utilized in large public buildings, necessitating research into their
progressive collapse resistance to assure user safety. The most significant part of improving the structural resilience of reticulated
domes is to evaluate their key elements. Based on a stiffness-based evaluation approach, this work offers a calculating procedure
for element importance coefficient. For both original and damaged structures, evaluations are carried out using the global
stiffness matrix and the determinant. The Kiewitt, Schwedler, and Sunflower reticulated domes are investigated to explore the
distribution characteristic of element importance coefficients in the single-layer dome structures. Moreover, the influence of the
load levels, load distributions, geometric parameters and topological features are also discussed. The results can be regarded as
the initial concept design reference for single-layer reticulated domes.
Key Words
importance coefficient; single-layer domes; stiffness; geometry; topology
Address
Qian Zhang:1) National Prestress Engineering Research Center, Key Laboratory of C & PC Structures of Ministry of Education Southeast University,
Nanjing 210096, China 2) Department of Structural Engineering and Building Materials, Faculty of Engineering and Architecture, Ghent University,
Valentin Vaerwyckweg 1, 9000 Ghent, Belgium
Wenxing Huang: School of Aerospace, The University of Nottingham Ningbo China. No.199 Taikang East Road, Ningbo, 315100, China
Yixiang Xu: School of Aerospace, The University of Nottingham Ningbo China. No.199 Taikang East Road, Ningbo, 315100, China
Jianguo Cai: National Prestress Engineering Research Center, Key Laboratory of C & PC Structures of Ministry of Education Southeast University,
Nanjing 210096, China
Fang Wang: National Prestress Engineering Research Center, Key Laboratory of C & PC Structures of Ministry of Education Southeast University,
Nanjing 210096, China
Jian Feng: National Prestress Engineering Research Center, Key Laboratory of C & PC Structures of Ministry of Education Southeast University,
Nanjing 210096, China
- Test study of precast SRC column under combined compression and shear loading Yang Chen, Lanqi Zhu and Yong Yang
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Abstract; Full Text (2288K) . | pages 265-275. | DOI: 10.12989/scs.2022.42.2.265 |
Abstract
A new type of precast steel reinforced concrete (PSRC) column was put forward in this paper. In order to study the
static performance of PSRC column and hollow precast steel reinforced concrete (HPSRC) column subjected to combined
compression and shear loading, a parametric test was carried out and effects of axial compression ratio, concrete strength and
shear ratio on the mechanical behavior of composite PSRC column and HPSRC column were explored. In addition, the cracks
development, load-span displacement relationship, strain distribution and shear bearing strength of column specimens were
emphatically focused. Test results implied that shear failure of all specimens occurred during the test, and higher strength of castin-place concrete, smaller shear ratio and larger axial compression ratio could lead to greater shear resistance, but when the axial
compression ratio was larger than 0.36, the shear capacity began to decrease gradually. Furthermore, truss-arch model for
determining the shear strength of PSRC column and HPSRC column was proposed and the calculated results obtained from
proposed method were verified to be valid.
Key Words
compression and shear test; mechanical behavior; precast SRC column; shear capacity
Address
Yang Chen: 1) Department of Civil Engineering, Shanghai University, Shanghai, 200444, China
2) State Key Laboratory of Green Building in Western China, Xi
- Impact response of a novel flat steel-concrete-corrugated steel panel Jingyi Lu, Yonghui Wang, Ximei Zhai and Hongyuan Zhou
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Abstract; Full Text (2639K) . | pages 277-288. | DOI: 10.12989/scs.2022.42.2.277 |
Abstract
A novel flat steel plate-concrete-corrugated steel plate (FS-C-CS) sandwich panel was proposed for resisting impact
load. The failure mode, impact force and displacement response of the FS-C-CS panel under impact loading were studied via
drop-weight impact tests. The combined global flexure and local indentation deformation mode of the FS-C-CS panel was
observed, and three stages of impact process were identified. Moreover, the effects of corrugated plate height and steel plate
thickness on the impact responses of the FS-C-CS panels were quantitatively analysed, and the impact resistant performance of
the FS-C-CS panel was found to be generally improved on increasing corrugated plate height and thickness in terms of smaller
deformation as well as larger impact force and post-peak mean force. The Finite Element (FE) model of the FS-C-CS panel
under impact loading was established to predict its dynamic response and further reveal its failure mode and impact energy
dissipation mechanism. The numerical results indicated that the concrete core and corrugated steel plate dissipated the majority
of impact energy. In addition, employing end plates and high strength bolts as shear connectors could prevent the slip between
steel plates and concrete core and assure the full composite action of the FS-C-CS panel.
Key Words
drop-weight impact test; failure mode; finite element simulation; impact response; steel-concrete-steel panel
Address
Jingyi Lu:1) Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, Harbin Institute of Technology, Harbin 150090, China
2) Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology,
Harbin Institute of Technology, Harbin 150090, China
Yonghui Wang:1) Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, Harbin Institute of Technology, Harbin 150090, China
2) Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology,
Harbin Institute of Technology, Harbin 150090, China
Ximei Zhai: 1) Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, Harbin Institute of Technology, Harbin 150090, China
2) Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology,
Harbin Institute of Technology, Harbin 150090, China
Hongyuan Zhou: Key Lab of Urban Security and Disaster Engineering of Ministry of Education, Beijing University of Technology, Beijing 100124, China