Abstract
This paper proposes a composite form of fuzzy adaptive control plan based on a robust observer. The fuzzy 2D
control gains are regulated by the parameters in the LMIs. Then, control and learning performance indices with weight matrices
are constructed as the cost functions, which allows the regulation of the trade-off between the two performance by setting
appropriate weight matrices. The design of 2D control gains is equivalent to the LMIs-constrained multi-objective optimization
problem under dual performance indices. By using this proposed smart tracking design via fuzzy nonlinear criterion, the data
link can be further extended. To evaluate the performance of the controller, the proposed controller was compared with other
control technologies. This ensures the execution of the control program used to track position and trajectory in the presence of
great model uncertainty and external disturbances. The performance of monitoring and control is verified by quantitative
analysis. The goals of this paper are towards access to adequate, safe and affordable housing and basic services, promotion of
inclusive and sustainable urbanization and participation, implementation of sustainable and disaster-resilient buildings,
sustainable human settlement planning and manage. Therefore, the goal is believed to achieved in the near future by the ongoing
development of AI and control theory.
Key Words
adaptive system; complex structural control; fuzzy model and NN; Lyapunov energy function; perturbationbased control
Address
ZY Chen, Ruei-Yuan Wang and Yahui Meng:School of Science, Guangdong University of Petrochemical Technology, Maoming 525000, P.R. China
Timothy Chen:Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, U.S.A.
Abstract
Steel moment resisting frames (MRFs) typically have inter-story drift concentrations at lower stories during
earthquakes as found from previous research. Hinged walls (HWs) can be used as structural strengthening components to force
the MRFs deform uniformly along the building height. However, large moment demands are often observed on HWs and make
the design of HWs non-economical. This paper proposes a method to reduce the moment demand on HWs using a ductile
connection system between the MRFs and the HWs. The ductile connection system is designed with a yield strength and energy
dissipation capacity, for the purpose of limiting the seismic forces transferred to the HWs and dissipating seismic energy.
Nonlinear time history analyses were performed using 10 far-filed earthquakes at maximum considered earthquake level. The
analysis results show that the proposed ductile connection system can reduce: (1) seismic moment demands in the HWs; (2)
floor accelerations; (3) the connection force between HWs and MRFs.
Key Words
ductile connection system; hinged wall; steel moment resisting frame; seismic performance
Address
Zhi Zhang:Thornton Tomasetti Inc., 120 Broadway, New York City, U.S.A.
Yulong Feng:School of Civil Engineering, Hefei University of Technology, Hefei, China
Dichuan Zhang:School of Engineering and Digital Sciences, Nazarbayev University, Nur-Sultan City, Kazakhstan
Zuanfeng Pan:Department of Civil and Environment Engineering, School of Engineering and Digital Sciences, Nazarene University, Astana, Kazakhstan
Abstract
The network theory studies interconnection between discrete objects to find about the behavior of a collection of
objects. Also, nanomaterials are a collection of discrete atoms interconnected together to perform a specific task of mechanical
or/and electrical type. Therefore, it is reasonable to use the network theory in the study of behavior of super-molecule in nanoscale. In the current study, we aim to examine vibrational behavior of spherical nanostructured composite with different
geometrical and materials properties. In this regard, a specific shear deformation displacement theory, classical elasticity theory
and analytical solution to find the natural frequency of the spherical nano-composite structure. The analytical results are
validated by comparison to finite element (FE). Further, a detail comprehensive results of frequency variations are presented in
terms of different parameters. It is revealed that the current methodology provides accurate results in comparison to FE results.
On the other hand, different geometrical and weight fraction have influential role in determining frequency of the structure.
Key Words
complex networks; mathematical simulation; mechanical behavior; nanotechnology
Address
Jie Xia: Tianjin University of Commerce, Tianjin 300133, China
Gholamreza Soleimani Jafari:Department of Mechanical Engineering, Kashan Branch, Islamic Azad University, Kashan, Iran
F. Ghoroughi: Department of Mechanics, Malay University, Malaysia
Abstract
Bonding carbon fiber-reinforced polymer (𝐶𝐹𝑅𝑃) laminates have been extensively employed in the restoration of
steel constructions. In addition to the mechanical properties of the 𝐶𝐹𝑅𝑃, the bond strength (𝑃𝑈) between the 𝐶𝐹𝑅𝑃 and steel
is often important in the eventual strengthened performance. Nonetheless, the bond behavior of the 𝐶𝐹𝑅𝑃-steel (𝐶𝑆) interface is
exceedingly complicated, with multiple failure causes, giving the 𝑃𝑈 challenging to forecast, and the 𝐶𝐹𝑅𝑃-enhanced steel
structure is unsteady. In just this case, appropriate methods were established by hybridized Random Forests (𝑅𝐹) and support
vector regression (𝑆𝑉𝑅) approaches on assembled 𝐶𝑆 single-shear experiment data to foresee the 𝑃𝑈 of 𝐶𝑆, in which a
recently established optimization algorithm named Aquila optimizer (𝐴𝑂) was used to tune the 𝑅𝐹 and 𝑆𝑉𝑅 hyperparameters.
In summary, the practical novelty of the article lies in its development of a reliable and efficient method for predicting bond
strength at the 𝐶𝑆 interface, which has significant implications for structural rehabilitation, design optimization, risk mitigation,
cost savings, and decision support in engineering practice. Moreover, the Fourier Amplitude Sensitivity Test was performed to
depict each parameter's impact on the target. The order of parameter importance was 𝑡𝑐〉 𝐿𝑐 >〉𝐸𝐴 〉 𝑡𝐴 >〉𝐸𝑐 〉 𝑏𝑐 〉𝑓𝑐 〉
𝑓𝐴 from largest to smallest by 0.9345 〉0.8562 〉 0.79354 〉 0.7289 〉 0.6531 〉 0.5718 〉 0.4307 〉 0.3657. In three training,
testing, and all data phases, the superiority of 𝐴𝑂 − 𝑅𝐹 with respect to 𝐴𝑂 − 𝑆𝑉𝑅 and 𝑀𝐴𝑅𝑆 was obvious. In the training
stage, the values of 𝑅
2
and 𝑉𝐴𝐹 were slightly similar with a tiny superiority of 𝐴𝑂 − 𝑅𝐹 compared to 𝐴𝑂 − 𝑆𝑉𝑅 with
𝑅
2
equal to 0.9977 and 𝑉𝐴𝐹 equal to 99.772, but large differences with results of 𝑀𝐴𝑅𝑆.
Key Words
aquila optimizer; bond strength prediction; carbon fiber reinforced polymer-steel interface; hyperparameter
tuning; regression analysis
Address
Xiaomei Sun, Xiaolei Dong, Weiling Teng:1) School of Civil Engineering, Xijing University, Xi
Abstract
The bonding efficacy of steel I-section embedded in metakaolin-fly ash-based geopolymer concrete (MK-FA-GC)
was investigated in this study. Push-out tests were conducted on nine column specimens to evaluate the influence of compressive
strength of concrete, embedded length of steel I-section, thickness of concrete cover, and stirrup ratio on the bond performance.
Failure patterns, load-slip relationships, bond strength, and distribution of bond stress among the specimens were analyzed. The
characteristic bond strength of geopolymer concrete (GC) increased with higher compressive strength, longer embedded steel
section length, thicker concrete cover, and larger stirrup ratio. Empirical formulas for bond strength at the loading end were
derived based on experimental data and a bond-slip constructive model for steel-reinforced MK-FA-GC was proposed. The
calculated bond-slip curves showed good agreement with experimental results. Furthermore, numerical simulations using
ABAQUS software were performed on column specimens by incorporating the suggested bond-slip relationship into connector
elements to simulate the interface behavior between MK-FA-GC and the steel section. The simulation results showed a good
correlation with the experimental findings.
Key Words
bond-slip constitutive model; bond strength; geopolymer concrete; numerical simulation; push-out test; steel
section
Address
Hang Sun, Juan Chen and Xianyue Hu:School of Urban Construction, Yangtze University, 1 Nanhuan Road, Jingzhou, Hubei, China
Abstract
While the external axial compressive load is applied to only the shell edge of stringer-stiffened shell in the most of
numerical and analytical previous studies (entitled as conventional approach), a part of external load is applied to the stringers in
real conditions. It leads to decrease the accuracy of the axial buckling load calculated by the conventional eigenvalue analysis
approach performed in the most of previous studies. In this study, the distribution of stress in the pre-buckling analysis was
enhanced by applying the axial external compressive load to both shell and stringers to perform an accurate eigenvalue analysis
of the stringer-stiffened composite shell. In this regard, a model was developed in FORTRAN environment to simulate the
laminated stringer-stiffened shell under axial compressive load using finite strip method. The axial buckling load of the shell was
obtained through eigenvalue analysis. A comparison was made between the results obtained from the model and those available
in the previous studies to evaluate the validity of the results obtained from the model. Through a parametric study, the effects of
different parameters such as stringer properties and composite layup on the buckling load of the shell under different loading
patterns were investigated. The results indicated that in some cases, the axial buckling load obtained for the conventional
approach used in the most of previous studies is significantly overestimated or underestimated due to neglecting the stringer in
distribution of external load applied to the stringer-stiffened shell. According to the results obtained from the parametric study,
some graphs were derived to show the accuracy of the axial buckling load obtained from the conventional approach utilized in
the literature.
Address
Davood Poorveis, Amin Khajehdezfuly and Mohammad Reza Sardari: Department of Civil Engineering, Faculty of Civil Engineering and Architecture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Shapour Moradi:Department of Mechanical Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Abstract
This research experimentally evaluated the local stress distribution along the cross-section of composite beams
under both positive and negative moments. The experiment utilized a large-scale, two-story, two-by-three bay steel gravity frame
with a concrete on metal deck floor system. The composite shear connections, which are nominally assumed to be pinned under
gravity loading, can develop non-negligible moment-resisting capacity when subjected to lateral loads. This paper discusses the
local stress distribution, or shear lag effects, observed near the beam-to-column connections when subjected to combined gravity
and lateral loading. Strain gauges were used for measurements along the beam depth at varying distances from the connection.
The experimental data showed amplified shear lag effects near the unconnected region of the beam web and bottom flange under
the applied loading conditions. These results indicate that strain does not vary linearly across the beam cross-section adjacent to
the connection components. This insight has implications for the use of experimental strain gauge data in estimating beam
demands near the connections. These findings can be beneficial in informing instrumentation plans for future experimental
studies on composite beams.
Key Words
bolted double-angle connection; composite beams; composite shear connection; experimental testing; shear
lag effects
Address
Sangwook Park:Department of Civil and Environmental Engineering, Oklahoma State University, Stillwater, OK 74074, USA
Patricia Clayton:Department of Engineering, Wake Forest University, Winston-Salem, NC 27109, USA
Todd A. Helwig and Michael D. Engelhardt:Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX 78758, USA
Eric B. Williamson:Department of Civil and Mechanical Engineering, U.S. Military Academy, West Point, NY 10996, USA
Abstract
Steel arch supports are used in mines and underground structures to provide stability. Most of the supports are made
up of overlapping arches. They can behave either yieldingly or unyieldingly. If the normal force at any point of overlapping
equals the slip resistance, the slide occurs. This paper presents a solution procedure for determining the load-carrying capacity of
steel arch supports in the yielding implementation. This solution considers the effects of several significant elements, including
differing materials and the number of clamps in yielding friction joints. The direct stiffness method is applied. The solution
contains geometric, physical, and structural nonlinearity. The results obtained from numerical modeling using the provided
procedure are compared to laboratory tests conducted at GIG Katowice in 2012. They show a good correlation with previously
collected data from equivalent laboratory conditions.
Key Words
arch; deformation energy; direct stiffness method; slip resistance; slippage; steel structure; underground
construction; Winkler model; yielding support
Address
Lenka Koubova:Department of Structural Mechanics, Faculty of Civil Engineering, VSB - Technical University of Ostrava,
Ludvika Podeste 1875/17, 708 00 Ostrava-Poruba, Czech Republic
