Hanoi University of Civil Engineering (HUCE; Vietnamese: Trường Đại học Xây dựng Hà Nội) also known as the National University of Civil Engineering (NUCE) - a public higher education institution in Vietnam. The university is one of the leading universities and among the top 7 engineering universities in Vietnam.HUCE is one of four universities participating in educating high- qualified engineers of Vietnamese - French Courses. The University also has French speaking Civil Engineering Courses supported by AUPELF - a global network of French-speaking higher-education and research institutions.HUCE was officially founded in 1966 in the capital of Vietnam - Hanoi. It is considered to be a large university, teaching more than 18,000 undergraduate students and 2000 post-graduate students. The teaching staff is 699 specialists. The university has international partners which allows its students to participate in exchange programs.The university has 14 Faculties and 54 Departments, 16 laboratories and workshops. It offers bachelor's, master's and doctoral degrees. The main campus is in the Hanoi capital, district of Hai Ba Trung.The University has educated over 60,000 engineers and architects with more than 5,000 masters and doctors. Different generations of the University's lecturers and students have been working throughout the country, contributing profoundly to the national defense and development.
While FGM sandwich plates are prevalent in aerospace and civil engineering for their tunable multi-directional properties, there is a dearth of research on 3D-FGM plates that account for geometric nonlinearity and moving mass effects while being partially supported by an elastic foundation. This paper presents a nonlinear finite element model based on Shi's higher-order plate theory and von Karman geometric nonlinearity to analyse the nonlinear dynamic response of sandwich plates partially supported on an elastic foundation. The sandwich plate consists of two outer layers made of three-dimensional functionally graded material (3D-FGM) and a core layer of two-dimensional functionally graded material (2D-FGM), both fabricated from ceramics and metals using power-law distributions. The equations of motion of the plate under the influence of a moving mass are derived via Hamilton's principle and solved using the Newmark-beta method in conjunction with the Newton-Raphson iterative scheme. Numerical results not only demonstrate the convergence and accuracy of the established model when compared with results published in the literature but are also used to evaluate and analyse the influence of volume fraction indices, geometric parameters, sandwich configuration, weight and velocity of the moving mass, and boundary conditions on the dynamic response of the sandwich plate. Several key findings are highlighted: (i) nonlinear models are essential for plates with low stiffness or few constraints (e.g., SFSF), where linear models overestimate deflection by up to 40%; (ii) volume fraction indices px,py,pz and layer thickness ratios are effective design parameters for controlling structural stiffness; (iii) the shear stiffness coefficient of a partially elastic foundation has a stronger influence on deflection reduction than the Winkler stiffness coefficient; and (iv) the dynamic amplification coefficient peaks within a critical velocity range before decreasing.
This paper focuses on the investigation of the free vibration and buckling behaviour of honeycomb auxetic bidirectional functionally graded sandwich (2D-FGASW) plates. The 2D-FGASW plates under consideration consist of two face sheets made of bi-directional functionally graded materials (2D-FGM) whose mechanical properties vary along thickness and longitudinal directions according to the power law and a core made of a re-entrant auxetic honeycomb material with a negative Poisson's ratio. The face sheets incorporate a combination of two ceramics and one metallic material, providing a diverse range of mechanical characteristics. The core is fabricated from the same metallic material used in the face sheets, ensuring compatibility and continuity throughout the structure. A finite element model is developed using a four-node rectangular element, with eight degrees of freedom per node. This model is based on the four-variable shear deformation refined plate theory and Hamilton's principle. To ensure the reliability and accuracy of the proposed model, several comparative examples are presented, demonstrating its convergence and capability in capturing the behaviour of the plates. Finally, some new investigations evaluating the influence of material and geometrical parameters on the vibration and buckling responses of the 2D-FGASW plates are presented in detail, shedding light on the design considerations necessary for optimizing their performance.
In this paper, for the first time, the static bending and free vibration of bi-directional functionally graded (2D-FG) nanobeams partially resting on an elastic foundation are investigated. The nanobeams are composed of four material components and exhibit mechanical characteristics that vary smoothly and continuously along the thickness and length of the beam according to a power law. For the purpose of analysis, a finite element model is established using a two-node beam element, with each node having five degrees of freedom, combining Lagrangian and Hermitian shape functions. Based on a higher-order shear deformation theory and nonlocal theory, the governing equations of the 2D-FG nanobeams are derived using Hamilton's principle. Through the comparisons of the results obtained from the model with published results in the open literature, the accuracy and reliability of the present model are confirmed. Therefore, the proposed algorithm is compatible for predicting mechanical behaviors of nanobeams with arbitrary material distribution, various boundary conditions and complex loads. New numerical results are conducted to assess the influence of parameters such as volume fraction indexes, nonlocal parameters, foundation coefficients, length-to-height ratio and boundary conditions on the bending static and free vibration behaviors of the 2D-FG nanobeams. Especially, the role of the partial elastic foundations on the bending and vibration of the 2D-FG nanobeams is extensively investigated.
Landslides in mountainous regions, such as Son La province in northern Vietnam, pose significant risks to human life, property, and infrastructure. Rapid urbanization and deforestation in Vietnam exacerbate landslide risks, making effective landslide risk assessment crucial for disaster mitigation and management. This study introduces a new integrated framework combining machine learning models and multi-criteria decision analysis to estimate landslide risk. We utilized 1,771 landslide locations from various sources and fifteen landslide influencing factors as model input to create landslide susceptibility maps using advanced hybrid machine learning models. The Analytic Hierarchy Process is used to weight indicators of social-economic and infrastructure impacts, resulting in a comprehensive landslide risk assessment map. The final risk map showed the landslide susceptibility and consequences in a matrix, highlighting that 3.25
Through 57 finite element method investigations on the thermal behavior of a mass concrete foundation cast continuously from two horizontal layers with varying thicknesses and heat properties, this study evaluated the influence of the most important factors impacting the temperature field raised within structure and proposed a predictive model taking seven primary input parameters, including the cement contents of the two concrete layers, curing and placing temperatures, the associated layer thickness ratio, and structural dimensions, into account for predicting the peak temperature (Tmax) and the maximum temperature difference (Delta Tmax) within the massive concrete foundation. The validity of the proposed model is confirmed by comparing its predictions with observations from three published experiments and their corresponding numerical simulations. These comparisons reveal that (i) the proposed model can accurately estimate the values of Tmax and Delta Tmax for variously shaped massive concrete structures within a ratio of total surface area to volume (A/V) range of 0.84 to 2.8; (ii) despite differing shapes, the massive structures share a similar A/V ratio, leading to similar Tmax and Delta Tmax values; and (iii) a proportional relationship exists between Tmax, Delta Tmax, and the A/V ratio, with Tmax decreasing and Delta Tmax increasing as the A/V ratio decreases.
