HCMCOU Journal of Science – Advances in Computational Structures

In-plane and out-of-plane bending vibration analysis of the laminated composite beams using higher-order theories

2025-01-15T11:23:23+07:00

In this paper, relatively new higher-order shear deformation theories are presented for a thorough analysis of the in-plane and out-of-plane vibrational characteristics of laminated composite beams. Through the introduction of new displacement fields and the consideration of rotary inertia and Poisson’s effect, the kinetic and potential energies of the beams have been derived. This formulation, displaying significant generality, accommodates arbitrary stacking sequences. Utilizing the finite element method, a new element has been presented for calculating the beam’s vibrational characteristics. Featuring three nodes, each with seven degrees of freedom, this higher-order element provides a detailed representation of complex behaviors. Mass and stiffness matrices were derived using the energy method, and boundary conditions were applied through the penalty approach. The results exhibit a good degree of consistency and alignment with those obtained from the 3D commercial software ANSYS, validating the accuracy and reliability of the proposed methodology for structural analysis. This comprehensive approach contributes to advancing the understanding and modeling of laminated composite beams in diverse engineering applications. The effects of different parameters on the in-plane and out-of-plane vibration analysis of laminated composite beams have been investigated in detail.

Nonlinear and crack propagation analysis of concrete dams: A comparative study of 2D and 3D models

2025-01-15T11:23:25+07:00

The nonlinear behavior and crack propagation in concrete dams, particularly at spillway sections where section variations can induce excessive local stresses, pose significant challenges for designers. While many designs rely on 2D models due to their simplicity and reduced computational demands, this common approach may underestimate stress concentrations and potential damage at critical spillway sections. This study undertakes a comparative analysis of 2D and 3D simulations of a concrete gravity dam using the finite element program ABAQUS. Our findings indicate that 3D simulations more accurately detect damage at stress concentration points, underscoring the importance of employing rigorous 3D models for complex sections of concrete gravity dams to ensure structural integrity and safety.

Damage detection of beam-like structures using wavelet transform and subtraction of intact and damaged mode shapes

2025-01-15T11:23:27+07:00

Detecting damages with low levels presents a significant challenge in structural assessment. Many existing methods fail to detect damages or cracks below a severity threshold of 10%. Localizing on-surface damages, especially those with low levels, adds to this complexity. This study introduces a novel technique to address these issues by employing wavelet transformation on the difference between damaged and intact mode shapes. A finite element model is developed to derive the governing equations for thin beams, yielding the mode shape signals necessary for analysis. These signals are subsequently decomposed using wavelet transform. Both numerical simulations and experimental validations confirm the method’s efficacy in detecting on-surface damages below the 10% level.

Decision-making in structural engineering using BHARAT-II method

2025-01-15T11:23:28+07:00

This paper presents a novel Multi-Attribute Decision-Making (MADM) method, named BHARAT-II (Best Holistic Adaptable Ranking of Attributes Technique - II), to choose the best alternatives for different structural engineering-related problems. Two case studies are provided to illustrate the suggested MADM method. The first case study deals with three problems. The three problems are: (a). selecting the best construction method for a bridge out of 04 available methods considering 07 selection attributes, (b). selecting the best structural system of the bridge out of 07 structural systems considering 11 selection attributes, and (c). selecting the best construction material out of 04 materials considering 04 selection attributes. The challenge of choosing the ideal structural system for a housing project is covered in the second case study by considering 04 alternative structural systems and 05 selection attributes involving 19 sub-attributes. The results of the proposed BHARAT-II decision-making method are compared with those of other MADM methods. The proposed method is adaptable to solve the best alternative selection problems of structural engineering.

An efficient computational system for defect prediction through neural network and bio-inspired algorithms

2025-01-15T11:23:29+07:00

Detecting and locating damage is essential in maintaining structural integrity. While Artificial Neural Networks (ANNs) are effective for this purpose, their performance can be significantly improved through advanced optimization techniques. This study introduces a novel approach using the Grasshopper Optimization Algorithm (GOA) to enhance ANN capabilities for predicting defective aluminum plates. The methodology begins by deriving input parameters from natural frequencies, with defect locations as the output. A Finite Element Model (FEM) is used to simulate data by varying defect locations, creating a comprehensive dataset. To validate this approach, experimental data from vibration analyses of plates with different defect locations is collected. We then compare the performance of our GOA-optimized ANN against other metaheuristic algorithms, such as the Cuckoo Search Algorithm (CSA), Bat Algorithm (BA), and Firefly Algorithm (FA). Notably, CSA’s performance is slightly close to GOA. The results show that our GOA-based method outperforms these traditional algorithms, demonstrating superior accuracy in damage prediction. This advancement holds significant potential for applications in structural integrity monitoring and maintenance.