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CONTENTS
Volume 51, Number 5, June 10 2024
 


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 paper delves into an emerging paradigm shift in architectural design, focusing on the development of a cuttingedge methodological framework for the artistic enhancement of nanocomposite brick facades in building construction. This innovative approach represents a fusion of art and science, harnessing the potential of advanced nanotechnology to redefine the aesthetic and functional properties of building exteriors. Central to this new methodology is the integration of state-of-the-art materials and fabrication techniques, aimed at not only elevating the visual appeal of architectural structures but also enhancing their structural robustness and environmental sustainability. By leveraging the unique characteristics of nanocomposite materials, the proposed method opens up new possibilities for pushing the boundaries of traditional brick facade design. Through a meticulous exploration of the intricacies involved in implementing this novel approach, the paper elucidates the transformative impact it can have on the architectural landscape. By marrying creativity with technical precision, the method environment for art design of nanocomposite brick facades promises to usher in a new era of sustainable, visually captivating, and structurally resilient building facades that are poised to redefine the very essence of architectural aesthetics.

Key Words
art design; building; nanocomposite brick; 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.

Key Words
axial buckling; composite layup; composite material; eigenvalue method; stringer stiffened shell

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


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