• Structural Engineering and Mechanics
• /
• v.63 no.4
• /
• pp.439-446
• /
• 2017

This work proposes an original single variable shear deformation theory to study the buckling analysis of thick isotropic plates subjected to uniaxial and biaxial in-plane loads. This theory is built upon the classical plate theory (CPT) including the exponential function in terms of thickness coordinate to represent shear deformation effect and it involves only one governing differential equation. Efficacy of the present theory is confirmed through illustrative numerical examples. The obtained results are compared with those of other higher-order shear deformation plate theory results.

• Structural Engineering and Mechanics
• /
• v.54 no.3
• /
• pp.579-595
• /
• 2015

A general geometrically non-linear model for lateral-torsional buckling of thick and thin-walled FGM box beams is presented. In this model primary and secondary torsional warping and shear effects are taken into account. The coupled equilibrium equations obtained from Galerkin's method are derived and the corresponding tangent matrix is used to compute the critical moments. General expression is derived for the lateral-torsional buckling load of unshearable FGM beams. The results are validated by comparison with a 3D finite element simulation using the code ABAQUS. The influences of the geometrical characteristics and the shear effects on the buckling loads are demonstrated through several case studies.

• Earthquakes and Structures
• /
• v.8 no.1
• /
• pp.253-273
• /
• 2015

The current investigation has been conducted to examine the effect of gravity loads on the seismic responses of the doubly asymmetric, three-dimensional structures comprising walls and frames. The proposed model includes the P-${\Delta}$ effects induced by the building weight. Based on the variational approach, a 3D finite element with two nodes and six DOF per node including P-${\Delta}$ effects is formulated. Dynamic and static governing equations are derived for dynamic and buckling analyzes of buildings braced by wall-frame systems. The influences of P-${\Delta}$ effects and height of the building on tip displacements under Hachinohe earthquake record are investigated through many structural examples.

• Journal of Public Diplomacy
• /
• v.2 no.1
• /
• pp.116-135
• /
• 2022

Public diplomacy activities can benefit from social capital theory, when its social dynamics is elucidated in the investment of complex social networks and in the establishment and management of relationships with foreign publics. Social capital theory explains that actors can produce purposive actions to mobilize resources in social structures, which thus explains the dynamics of social interactions. In response to the lack of conceptual frameworks for understanding public diplomacy activities within social capital theory, we conducted a narrative literature review that intends to identify the means through which international actors, such as governments, engage with foreign publics through the dynamics of social networks and the resources embedded in them. In addition, we explored the multidimensional characteristics of social capital to enhance the comprehension of the manner in which actors access, share, and maintain resources in target communities, institutions, or organizations through public diplomacy activities. In summary, we highlight the importance of new theoretical explorations on the application of social capital theory to public diplomacy and the need for a research agenda in the field.

• Structural Monitoring and Maintenance
• /
• v.11 no.2
• /
• pp.149-171
• /
• 2024

Drive-by monitoring (also known as indirect monitoring or mobile sensing) of bridges has obvious advantages when compared to other approaches of Structural Health Monitoring. The underlying concept involves leveraging the coupling between the vertical vibrations of the bridge and those generated in the passing vehicle. In this scenario, the vehicle serves as both the initiator and recipient of the vibrations, which can provide information on the structural condition of the bridge. In the literature, a wide range of methods has been proposed, primarily focused on highway bridges. However, limited research has been published to assess the suitability of indirect methods for monitoring railway bridges, bounded to numerical studies based on theoretical simulations and, rarely, on experimental investigations. The aim of this work is to contribute to filling this gap and explore the feasibility of implementing drive-by monitoring for railway bridges using in-service vehicles and discuss its potential applicability, from theoretical and practical point of view, with illustration through real case studies from the Moroccan railway network.

• Proceedings of the Korean Institute of Landscape Architecture Conference
• /
• 2017.10a
• /
• pp.28-29
• /
• 2017

• Smart Structures and Systems
• /
• v.20 no.3
• /
• pp.369-383
• /
• 2017

In this work, the effects of moisture and temperature on free vibration characteristics of functionally graded (FG) nanobeams resting on elastic foundation is studied by proposing a novel simple trigonometric shear deformation theory. The main advantage of this theory is that, in addition to including the shear deformation influence, the displacement field is modeled with only 2 unknowns as the case of the classical beam theory (CBT) and which is even less than the Timoshenko beam theory (TBT). Three types of environmental condition namely uniform, linear, and sinusoidal hygrothermal loading are studied. Material properties of FG beams are assumed to vary according to a power law distribution of the volume fraction of the constituents. Equations of motion are derived from Hamilton's principle. Numerical examples are presented to show the validity and accuracy of present shear deformation theories. The effects of hygro-thermal environments, power law index, nonlocality and elastic foundation on the free vibration responses of FG beams under hygro-thermal effect are investigated.

• Structural Engineering and Mechanics
• /
• v.64 no.4
• /
• pp.391-402
• /
• 2017

In this paper, a new nonlocal trigonometric shear deformation theory is proposed for thermal buckling response of nanosize functionally graded (FG) nano-plates resting on two-parameter elastic foundation under various types of thermal environments. This theory uses for the first time, undetermined integral variables and it contains only four unknowns, that is even less than the first shear deformation theory (FSDT). It is considered that the FG nano-plate is exposed to uniform, linear and sinusoidal temperature rises. Mori-Tanaka model is utilized to define the gradually variation of material properties along the plate thickness. Nonlocal elasticity theory of Eringen is employed to capture the size influences. Through the stationary potential energy the governing equations are derived for a refined nonlocal four-variable shear deformation plate theory and then solved analytically. A variety of examples is proposed to demonstrate the importance of elastic foundation parameters, various temperature fields, nonlocality, material composition, aspect and side-to-thickness ratios on critical stability temperatures of FG nano-plate.

• The Journal of the Korea Contents Association
• /
• v.19 no.11
• /
• pp.102-110
• /
• 2019

The military respond well to external publics in the event of a crisis int that they are operated based on the trust of the people. Unlike other organizations, however, the Korean military has the distinctiveness that soldiers experience military life as internal publics for a certain period of time and after serving in the army, they become those who evaluate the military as external publics. Therefore, it is important to examine what would be effective crisis management strategies in terms of communicating with active-duty soldiers. Given that active-duty soldiers are accustomed to using SNS these days, this study investigated whether message forms (digital image vs. text) affect the perception of the military in crisis, acceptance of the given message, and attitude toward the military. Our empirical findings suggest that image-based messages are more likely to increase levels of message acceptance than text-based messages. Based on the results, we discussed practical implications on communication strategies for managing the military in crisis.

• Geomechanics and Engineering
• /
• v.10 no.3
• /
• pp.357-386
• /
• 2016

In this research work, an exact analytical solution for thermal stability of solar functionally graded rectangular plates subjected to uniform, linear and non-linear temperature rises across the thickness direction is developed. It is assumed that the plate rests on two-parameter elastic foundation and its material properties vary through the thickness of the plate as a power function. The neutral surface position for such plate is determined, and the efficient hyperbolic plate theory based on exact neutral surface position is employed to derive the governing stability equations. The displacement field is chosen based on assumptions that the in-plane and transverse displacements consist of bending and shear components, and the shear components of in-plane displacements give rise to the quadratic distribution of transverse shear stress through the thickness in such a way that shear stresses vanish on the plate surfaces. Therefore, there is no need to use shear correction factor. Just four unknown displacement functions are used in the present theory against five unknown displacement functions used in the corresponding ones. The non-linear strain-displacement relations are also taken into consideration. The influences of many plate parameters on buckling temperature difference will be investigated. Numerical results are presented for the present theory, demonstrating its importance and accuracy in comparison to other theories.