Abstract
The present study conducts a free vibration analysis of functionally graded (FG) multilayer thick porous plates
reinforced with carbon nanotubes within the framework of the Carrera Unified Formulation (CUF). The material properties,
including CNT weight fraction and porosity, exhibit a layer-wise gradual variation through the thickness of the plate. The
Element-Free Galerkin (EFG) method is employed to obtain the natural frequencies of FG CNT/polymer-reinforced porous
multilayer thick plates. A modified Halpin-Tsai micromechanical model and the rule of mixtures are used to predict the effective
properties of porous materials reinforced with CNTs. The obtained results are compared with other higher deformation theories,
and they demonstrate the accuracy and efficiency of the proposed EFG-CUF method. Finally, a parametric study is conducted to
show the effect of key parameters, including CNT weight fraction, porosity, number of layers, layer arrangement, thickness-to
width, and width-to-length ratios on the natural frequencies of the plate.
Key Words
Carrera formulation; composite materials; Element-Free Galerkin (EFG) method; free vibration analysis;
functional graded; multilayer thick plates; natural frequency of structure; porosity; carbon nanotubes
Address
Ali Akbar Abolfathi:Department of Civil Engineering, Faculty of Engineering Science, Quchan University of Technology, Quchan, Iran
Mohammad Hossein Ghadiri Rad:Department of Civil Engineering, Faculty of Engineering Science, Quchan University of Technology, Quchan, Iran
Abstract
In this paper, the thermoelastic behavior of an axisymmetric clamped–clamped rotating thick truncated cone under
mechanical loading and bi-directional thermal loading is investigated. The governing equations are formulated as a set of non
homogeneous ordinary differential equations with variable coefficients. The solution of these equations is obtained by applying
boundary conditions and ensuring continuity between the layers using the multi-layer method (MLM) as a semi-analytical
approach based on the first-order shear deformation theory (FSDT). The results obtained from this study are compared with
finite element method (FEM) simulations, demonstrating good agreement.
Key Words
bi-directional; first-order shear deformation theory (FSDT); multi-layers method (MLM); rotating;
thermoelastic; thick truncated cone; pressure vessel
Address
Fatemeh Ramezani:Department of Mechanical Engineering, Yasouj University, Yasouj, Iran
Mohammad Zamani Nejad:Department of Mechanical Engineering, Yasouj University, Yasouj, Iran
Mehdi Ghannad:Mechanical Engineering Faculty, University of Shahrood, Shahrood, Iran
Abstract
To investigate time-dependent behaviors of ultra-high performance concrete (UHPC)-filled anchorage system for
Carbon fiber-reinforced polymer (CFRP) cable under elevated temperature, high-temperature creep and relaxation tests were
conducted on CFRP cable-UHPC interface. The variation laws of creep slippage at loading end and relaxation stress of CFRP
cable-UHPC interface with different initial pullout load and effective bond length under different target temperature were
identified. High-temperature pullout tests were conducted on specimens after high-temperature creep or relaxation stage, for
obtaining its residual mechanical performance. The influence of thermos-mechanical coupling effect on bearing capacity for
CFRP cable-UHPC interface was quantified. Finally, practical models for determining high-temperature creep and relaxation
laws of CFRP cable-UHPC interface and calibrating relationship between creep and relaxation behaviors under high temperature
at steady stage for CFRP cable-UHPC interface were developed. The obtained results demonstrated that both creep slippage
time and stress loss-time curves of CFRP cable-UHPC interface under target temperature from 100 to 210°C display
deformation characteristics of two-stage including transient and steady stages. The growth rate of the creep slippage of CFRP
cable-UHPC interface increased with treatment temperature or initial pullout load, while the slippage growth rate of CFRP
cable-UHPC interface at transient creep stage increased with the decreasing bond length. The changing rule of relaxation stress
of CFRP cable-UHPC interface is similar with that of creep slippage. Slip failure is the dominant failure mode of CFRP cable
UHPC interface after experience of high-temperature creep or relaxation stage. Due to the thermo-mechanical coupling effects
in high-temperature creep and relaxation tests, the Bearing capacities for CFRP cable-UHPC interface decreased 0.21~12.37%
and 0.83~10.65%, respectively.
Key Words
bond-type anchorage; CFRP cable-UHPC interface; high-temperature creep and relaxation behaviors;
residual mechanical performance
Address
Zhengwen Jiang:1)Key Laboratory for Wind and Bridge Engineering of Hunan Province, College of Civil Engineering, Hunan University, Changsha, 410082, China
2)Key Laboratory for Damage Diagno4sis of Engineering Structures of Hunan Province, College of Civil Engineering, Hunan University, Changsha, 410082, China
Jiayang Zou:Key Laboratory for Damage Diagno4sis of Engineering Structures of Hunan Province, College of Civil Engineering, Hunan University, Changsha, 410082, China
Zhi Fang:Key Laboratory for Wind and Bridge Engineering of Hunan Province, College of Civil Engineering, Hunan University, Changsha, 410082, China
Yawei Fang:1)Key Laboratory for Wind and Bridge Engineering of Hunan Province, College of Civil Engineering, Hunan University, Changsha, 410082, China
2)Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong
Quanhao Li:Key Laboratory for Damage Diagno4sis of Engineering Structures of Hunan Province, College of Civil Engineering, Hunan University, Changsha, 410082, China
Abstract
Experimental study and finite element analysis were conducted to investigate the correction factor for tension
measurement of carbon fiber reinforced polymer (CFRP) strand cables using slant axial strain method. Axial tensile tests were
performed on 6 CFRP strand cables. A multi-scale finite element (MSFE) model was developed and validated against the test
results. Parametric analysis was performed and a practical formula for predicting the correction factor was developed. Finally,
the difference in the correction factors between anisotropic and isotropic strand cables was identified by studying effect of
anisotropy. The obtained results demonstrated that the correction factors of CFRP strand cables with different diameters (10.2
mm and 12 mm) and same lay distance-diameter ratio (50) were experimentally determined as 1.013 and 1.019, respectively.
Effects of lay distance-diameter ratio and the number of strand wires on the correction factor are significant, while influences of
cable diameter, fiber volume content ranging of 65~75%, and material properties of resin are marginal. The correction factors of
7, 19 and 37-wire CFRP strand cables with a lay distance-diameter ratio of 15 range from 1.084 to 1.149. The correction factor
of CFRP strand cables with significant anisotropy and a small lay distance-diameter ratio (15) is much greater than that of
isotropic strand cables.
Address
Zerun Li:Key Laboratory for Wind and Bridge Engineering of Hunan Province, College of Civil Engineering, Hunan University, Changsha, 410082, China
Zhengwen Jiang:Key Laboratory for Wind and Bridge Engineering of Hunan Province, College of Civil Engineering, Hunan University, Changsha, 410082, China
Zhi Fang:Key Laboratory for Wind and Bridge Engineering of Hunan Province, College of Civil Engineering, Hunan University, Changsha, 410082, China
Abstract
Adjustable telescopic steel props (ATSPs) are innovative temporary supports widely-used in construction sites. In
Turkey, ATSPs should be designed based on EN 1065, which requires a three-stage nonlinear analysis involving rather complex
calculations. Accordingly, almost all companies producing ATSPs in Turkey prefer either conducting tests or receiving technical
support from international companies. This study aims to derive differential equations required to determine the actual
characteristic strengths of ATSPs using the calculation method defined in EN 1065 and solve them analytically using the load
dependent support conditions. The use of the derived analytical solutions for the determination of the strength of a typical ATSP
is also illustrated in the paper. It has been shown that there are four fundamental limit states that should be checked in each stage
of an ATSP analysis: (i) flexural failure of the tubes, (ii) bearing failure of the inner tube, (iii) shear failure of the pin and (iv)
elastic buckling of the prop. If the analysis ends without reaching any of these limit states, it is assumed that the support of the
ATSP has failed. The analytical solutions derived in this study are expected to guide ATSP design and contribute to future studies
on optimal prop design.
Key Words
actual characteristic strength; adjustable telescopic steel prop; buckling; EN 1065; falsework; temporary
support
Address
Seval Pinarbasi:Department of Civil Engineering, Kocaeli University, Kocaeli, Turkiye
Mertkan Mete:Institute for Graduate Studies in Science and Engineering, Kocaeli University, Kocaeli, Turkiye
Aytug Seckin:Department of Civil Engineering, Kocaeli University, Kocaeli, Turkiye
Abstract
Owing to their exceptional durability and lower total life-cycle cost, reinforced sea-sand concrete-filled (circular)
stainless steel tubular (RSCFSST) columns offer a highly viable structural solution for coastal regions. To investigate the effects
of stirrup spacing and concrete type on the axial compression properties of circular RSCFSST columns, eight axial compression
tests were conducted on three types of specimens: circular RSCFSST short columns, reinforced normal concrete-filled stainless
steel tubular counterparts, and sea-sand concrete-filled stainless steel tubular (SCFSST) counterparts. The test results indicated
that the use of sea-sand concrete has minimal influence on the axial compression behavior of the circular RSCFSST column.
Furthermore, the circular RSCFSST columns exhibited superior compression resistance and ductility compared to their SCFSST
counterparts. Subsequently, a finite element (FE) model of the circular RSCFSST column was developed to perform mechanism
and parametric analyses. Mechanism analysis highlighted that the confinement provided by stainless steel stirrups significantly
enhances both the bearing capacity and ductility of core concrete. The parametric analysis further indicated that their axial
compression resistance increases with increasing concrete compressive strength, steel yield strength, steel tubular ratio, or
volumetric stirrup ratio. Based on these findings, new simplified models to forecast the axial compression resistance, axial
compression stiffness, and peak strains of circular RSCFSST columns were suggested.
Key Words
axial compression resistance; axial compression stiffness; finite element model; peak strain; reinforced sea
sand concrete-filled circular stainless steel tubular short columns; simplified model
Address
Zhibin Wang:College of Civil Engineering, Fuzhou University, Fuzhou, Fujian Province 350108, China
Chenhao Ye:College of Civil Engineering, Fuzhou University, Fuzhou, Fujian Province 350108, China
Chunguang Zhao:The First Company of China Eighth Engineering Bureau Ltd, Jinan, Shandong Province 250100, China
Deshan Li:School of Civil Engineering, Guangdong Construction Polytechnic, Qingyuan, Guangdong Province 511500, China
Jiting Lin:College of Civil Engineering, Fuzhou University, Fuzhou, Fujian Province 350108, China
