• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.95-103
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• 2001

The buckling of an orthotropic layer bonded to an orthotropic half-space with an interface crack subjected to compressive load under plane strain is analyzed. General solution to the stability equations describing the buckling behavior of both the layer and the half-space is expressed in terms of displacement functions. The displacement functions are represented by the solution of Cauchy-type singular integral equations, which are numerically solved. Numerical results of the critical buckling loads are presented fur various geometric parameters and material properties of both the layer and half-space.

• Steel and Composite Structures
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• v.9 no.4
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• pp.303-323
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• 2009

Charts for the bending moments in the closed rib orthotropic deck plate are derived, based on the method originally introduced by Pelikan and Esslinger. New charts are done for EN 1991-2 traffic load distribution schemes. The governing Huber plate equation is solved utilizing Fourier series for various bridge deck plate boundary conditions. Bending moments are given as a function of deck plate rigidities and span length between cross beams. Old diagrams according to DIN 1072, the new ones according to EN 1991-2 and FE analyses results are compared. For typical bridge orthotropic deck plates, it can be concluded that the new EN 1991-2 traffic loads produce larger mid-span bending moments when two lane schemes are used, then those of DIN 1072. For support moments, DIN 1072 gives larger values for any number of lanes, especially under span lengths of 5m. The relevant differences are up to 25%.

• Elastomers and Composites
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• v.57 no.3
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• pp.114-120
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• 2022

The tensile properties of the extruded PC film were measured in the extrusion direction and perpendicular to the extrusion direction. The measured properties were the elastic modulus and Poisson's ratio at the glass transition temperature of PC. The measured orthotropic properties of the film were used for the computer simulation of vacuum forming. In this simulation, three mold shapes were tested: dome, trapezoid, and cubic, and the vacuum was applied between the mold surface and the heated film. The stress, strain, thickness, and stretch ratio distributions of the film in different mold shapes were observed and compared. The thermoforming simulation method used in this study and the obtained results, considering the determined orthotropic properties, can be applied to the thermoforming of various three-dimensional shapes.

• Geomechanics and Engineering
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• v.25 no.4
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• pp.331-339
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• 2021

In this work, an analytical solution is provided for the dynamical response of an orthotropic non-homogeneous elastic material. The present study has engineering applications in the fields of geophysical physics, structural elements, plasma physics, and the corresponding measurement techniques of magneto-elasticity. The analytical performances for the elastodynamic equations has been solved regarding displacements. The influences of the rotation, the magnetic field, the non-homogeneity based radial displacement and the corresponding stresses in an orthotropic material are investigated. The variations of the stresses, the displacement, and the perturbation magnetic field have been illustrated. The comparisons is performed using the previous solutions in the magnetic field absence, the non-homogeneity and the rotation.

• Advances in concrete construction
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• v.11 no.4
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• pp.315-321
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• 2021

In this article, an analytical solution of the dynamical behavior in an orthotropic non-homogeneity elastic material using for elastodynamics equations is investigated. The effects of the magnetic field, the initial stress, and the non-homogeneity on the radial displacement and the corresponding stresses in an orthotropic material are investigated. The analytical solution for the elastodynamic equations has solved regarding displacements. The variation of the stresses, the displacement, and the perturbation magnetic field have shown graphically. Comparisons are made with the previous results in the absence of the magnetic field, the initial stress, and the non-homogeneity. The present study has engineering applications in the fields of geophysical physics, structural elements, plasma physics, and the corresponding measurement techniques of magneto-elasticity.

• Steel and Composite Structures
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• v.48 no.2
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• pp.145-161
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• 2023

This study investigates the influences of porosity on the stability of the orthotropic laminated plates under uniaxial and biaxial loadings based on the hyperbolic shear deformation theory. Three different porosity distribution are considered with three specific functions through the plate thickness. The stability equations of porous orthotropic laminated plates are derived by the virtual work principle. Applying the Galerkin method to partial differential equations, the critical buckling load relation of porous orthotropic laminated plates is obtained. After validating the accuracy of the proposed formulation in accordance with the available literature, a parametric analysis is performed to observe the sensitivity of the critical buckling load to shear deformation, porosity, orthotropy, loading factor, and different geometric properties.

• Structural Engineering and Mechanics
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• v.91 no.5
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• pp.459-468
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• 2024

This study presents a frictionless receding contact problem for an orthotropic elastic layer. It is assumed that the layer is supported by two rigid quarter planes and the material of the layer is orthotropic. The layer of thickness h is indented by a rigid cylindrical punch of radius R. The problem is modeled by using the singular integral equation method with the help of the Fourier transform technique. Applying the boundary conditions of the problem the system of singular integral equations is obtained. In this system, the unknowns are the contact stresses and contact widths under the punch and between the layer and rigid quarter planes. The Gauss-Chebyshev integration method is applied to the obtained system of singular integral equations of Cauchy type. Five different orthotropic materials are considered during the analysis. Numerical results are presented to interpret the effect of the material property and the other parameters on the contact stress and the contact width.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.3
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• pp.237-250
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• 2003

Since an orthotropic steel deck bridge has large number of design variables and shows complex structural behavior, it would be very difficult and impractical to directly use a Conventional Single Level (CSL) optimization algorithm for its optimum design. Thus, in this paper, an Improved Multi Level Design Synthesis (IMLDS) optimization algorithm is proposed to improve the computational efficiency. In the proposed IMLDS algorithm, a coordination method is introduced to divide the bridge into main girders and orthotropic steel deck with preserving the characteristics of the structural behavior. For an efficient optimization of the bridge, the IMLDS algorithm incorporates the various crucial approximation techniques such as constraints deletion, Automatic Differentiation (AD), stress reanalysis, and etc. In the case of orthotropic steel deck system, optimum design problems are characterized by mixed continuous discrete variables and discontinuous design space. Thus, a modified Genetic Algorithm (GA) is also applied to optimize discrete member design for orthotropic steel deck. From the numerical example, the efficiency and convergency of the IMLDS algorithm proposed in this paper is investigated. It may be positively stated that the IMLDS algorithm will lead to more effective and practical design compared with previous algorithms.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.2
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• pp.331-341
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• 1993

The propagating crack problems under dynamic antiplane mode in orthotropic material is studied in this paper. To analyze the dynamic fracture problems by theoretical method or experimental method in orthotropic material, it is important to know the dynamic stress intensity factor in the vicinity of crack tip. Therefore the dynamic stress field and dynamic displacement field with dynamic stress intensity factor of orthotropic material in mode III were derived. When the crack propagation speed approachs to zero, the dynamic stress components and dynamic displacement components derived in this paper are identical to the those of static state. In addition, the relationships between dynamic stress intensity factor and dynamic energy release rate are determined by using the concept of crack closure energy with the dynamic stresses and dynamic displacements derived in this paper. Finally, the characteristics of crack propagation are studied with the properties of orthotropic material and crack speed. The variation of angle .alpha. between fiber direction and crack propagating direction and crack propagation speed fairly effect on stress component and displacement component in crack tip. The influence of crack propagation speed on the speed on the stress and displacement is greater in the case of .alpha.=90.deg. than in the case of .alpha.=0.deg. and the faster the crack propagation speed, the greater the stress value and displacement value.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.46-54
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• 2015

Base on Korean design code, previous design code had not considered the effect of pavement on the orthotropic steel deck, however recent design code (Limit State Design Method, 2012) allowed to consider the effect of pavement on the orthotropic steel deck, and efforts to apply the stiffness of pavement to the deck continue. Meanwhile, research on the effect of ultra thin bridge deck overlay on the orthotropic steel deck is inadequate, previous study was limited in about fatigue stress and performance between pavement layer and the orthotropic steel deck. In this study, according to changing of pavement layer stiffness application, pavement materials, pavement thickness and steel deck thickness, analysis of deflection. In addition to base on this result, consider effectiveness of ultra-thin pavement stiffness application on the orthotropic steel deck.