HCMCOU Journal of Science – Advances in Computational Structures

Buckling of porous FGM beams considering the thickness stretching effect

2024-11-11T10:44:39+07:00

This study explores the incorporation of porosity in functionally graded structures. Researchers typically integrate the porosity function into the rule of mixtures without accounting for specific fabrication processes, which relate to the volume fraction of material constituents. This paper presents an analytical investigation of buckling behavior in functionally graded beams, introducing a novel perspective on porosity that directly connects it to the volume fraction. Two porosity schemes are examined: volume fraction-dependent porosity (VFD) and rule of mixtures-dependent porosity (RMD). Four types of porosity are defined: Even, Uneven, Linear (1), and Linear (2). A higher-order shear deformation theory is proposed, based on a generalized displacement field. The equilibrium equations are derived using the principle of virtual work and solved with the Galerkin method to accommodate various boundary conditions. This work thoroughly investigates how structural geometry, material combination parameters, porosity types, and boundary conditions impact the critical buckling loads of the functionally graded beam.

A Comparative study of metaheuristic algorithms in the identification of structural damage in composite beams

2024-12-02T11:34:19+07:00

Structural damage, whether visible or hidden, is an inevitable occurrence in all structures, machines, and tools, arising from factors such as machining processes, wear, and impact. Over the years, significant efforts in structural dynamics have been devoted to evaluating and reconciling numerical models with experimental data to accurately detect and quantify such damage. This study presents a comprehensive approach to identifying and quantifying structural damage in multilayer composite beams by first assessing the global modal and frequency differences between undamaged and damaged structures using the Frequency Response Function (FRF) method. These results are then utilized in various metaheuristic optimization algorithms to precisely detect and quantify the extent of the damage. The focus of this work is to evaluate the effectiveness of three optimization algorithms: the African Vulture Optimization Algorithm (AVOA), the Salp Swarm Algorithm (SSA), and the Whale Optimization Algorithm (WOA). These algorithms are tested on a composite structure to determine their accuracy and computational efficiency in identifying structural damage.

Crack detection in concrete structures using standard deviation of discrete wavelet transform

2024-12-03T10:37:10+07:00

Crack detection in concrete structures is an important issue in the maintenance and repair operations of the structures. Detecting and distinguishing cracks in concrete can help determine the structure's health and prevent the possibility of structural failure. An efficient method for separating cracks in concrete is to use wavelet transform. This paper proposes a new crack detection technique based on a two-dimensional discrete wavelet transform and the standard deviation obtained from its detail signals to select an optimum wavelet function. According to our findings, there is a significant relation between the statistical index standard deviation and the desired detail signal obtained from the two-dimensional discrete wavelet transform for selecting the optimum wavelet function. Specifically, results show that as the standard deviation of the matrix of detail signal increases by a given wavelet function, crack detection resolution increases by that wavelet function.