• Structural Engineering and Mechanics
• /
• v.16 no.1
• /
• pp.35-46
• /
• 2003

The histories and distributions of dynamic stresses in an orthotropic hollow cylinder under sinusoidal impact load are obtained by making use of eigenfunction expansion method in this paper. Dynamic equations for axially symmetric orthotropic problem are founded and results are carried out for a practical example in which an orthotropic hollow cylinder is in initially at rest and subjected to a dynamic interior pressure $p(t)=-{\sigma}_0(sin{\alpha}t+1)$. The features of the solution appear the propagation of the cylindrical waves. The other hand, a dynamic finite element solution for the same problem is also got by making use of structural software (ABAQUS) program. Comparing theoretical solution with finite element solution, it can be found that two kinds of results obtained by two different solving methods are suitably approached. Thus, it is further concluded that the method and computing process of the theoretical solution are effective and accurate.

• Steel and Composite Structures
• /
• v.18 no.6
• /
• pp.1479-1492
• /
• 2015

This study evaluated the localized stress condition of the real corroded deck surface of an orthotropic steel bridge because severe corrosion damage on the deck surface and fatigue cracking were reported. Thus, a three-dimensional finite element (FE) analysis model was created based on measurements of the corroded orthotropic steel deck surface to examine the stress level dependence on the corrosion condition. Based on the FE analysis results, it could be confirmed that a high stress concentration and irregular stress distribution can develop on the deck surface. The stress level was also increased by approximately 1.3-1.5 times as a result of the irregular corroded surface. It was concluded that this stress concentration could increase the possibility of fatigue cracking in the deck surface because of the surface roughness of the orthotropic steel bridge deck.

• Structural Engineering and Mechanics
• /
• v.64 no.1
• /
• pp.23-31
• /
• 2017

In the study, dynamic behavior of laminated orthotropic beams on elastic foundation is investigated. Consistent model presented here combines the finite element solution of the system with SAP2000 software and the calculation of soil parameters with MATLAB software using Modified Vlasov Model type elastic foundation. For this purpose, a computing tool is coded in MATLAB which employs Open Application Programming Interface (OAPI) feature of SAP2000 to provide two-way data flow during execution. Firstly, an example is taken from the literature to demonstrate the accuracy of the consistent FEM-Vlasov Model. Subsequently, the effects of boundary conditions, subsoil depth, elasticity modulus of subsoil, slenderness ratio, velocity of moving load and lamination scheme on the behavior of laminated orthotropic beams on elastic foundation are investigated on a new numerical example. It can be concluded that it is really convenient to use OAPI feature of SAP2000 to model this complex behavior of laminated orthotropic beams on elastic foundation under moving load.

• Smart Structures and Systems
• /
• v.13 no.1
• /
• pp.25-39
• /
• 2014

The axisymmetric dynamic instability of polar orthotropic sandwich annular plate combined with electrorheological (ER) fluid core layer and constraining layer are studied in this paper. And, the ER core layer and constraining layer are used to improve the stability of the annular plate system. The boundaries of instability regions for the polar orthotropic sandwich annular plate system are obtained by discrete layer annular finite element and the harmonic balance method. The rheological property of an electrorheological material, such as viscosity, plasticity, and elasticity can be controlled by applying different electric field strength. Thus, the damping characteristics of the sandwich system are more effective when the electric field is applied on the sandwich structure. Additionally, variations of the instability regions for the polar orthotropic sandwich annular plate with different applying electric field strength, thickness of ER layer and some designed parameters are investigated and discussed in this study.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2006.04a
• /
• pp.111-118
• /
• 2006

The elastic buckling strength of a corrugated culvert made of orthotropic material such as FRP was evaluated. The height and length of a corrugated wave and the thickness of the culvert were considered as factors affecting the buckling strength of the culvert. And also, the ratio of the longitudinal stiffness and transverse stiffness was considered as the parameter affecting on the buckling strength of the used orthotropic material. Buckling strengths of various corrugated culvert models with different shapes and stiffness ratio were evaluated by FE analyses and a formula to estimate the elastic buckling strength was suggested from the regression with FE analysis results. Analysis results show that a corrugated culvert has superior buckling strength to a general flat pipe and the suggested formula estimates accurate buckling strength of the corrugated culverts made of orthotropic material.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.8
• /
• pp.1273-1280
• /
• 2003

In this paper, transparent dynamic photoelastic experimental hybrid method for propagating cracks in orthotropic material was developed. Using transparent dynamic photoelastic experimental hybrid method, we can obtain stress intensity factor and separate the stress components from only isochromatic fringe patterns without using isoclinics. When crack is propagated with constant velocity, the contours of stress components in the vicinity of crack tip in orthotropic material are similar to those of isotropic material or orthotropic material with stationary crack under the static load. Dynamic stress intensity factors are decreased as crack growths. It was certified that the dynamic photoelastic experimental hybrid method was very useful for the analysis of the dynamic fracture mechanics.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.9
• /
• pp.856-862
• /
• 2010

In this paper, the power flow analysis(PFA) method was developed to predict the vibrational responses of coupled co-planar orthotropic plates in frequencies ranging from medium to high. To cover the power transmission and reflection at the joint of the orthotropic plates, the wave transmission approach is applied with the assumption that all the incident waves are normal to the joint. Through numerical analyses, the power flow energy density and intensity fields of coupled co-planar orthotropic plates were compared with those of classical modal solutions by changing the frequency and internal loss factor, and they show good agreement in terms of the global decay and the attenuation patterns of the energy density.

• Structural Engineering and Mechanics
• /
• v.24 no.6
• /
• pp.699-707
• /
• 2006

In the paper, a direct method of solution of the Navier equation is presented. An orthotropic thick hollow cylinder under a one-dimensional steady-state temperature distribution and a uniform magnetic field with general types of thermal and mechanical boundary conditions is considered. The Navier equation in terms of displacement is derived and solved analytically by the direct method, and magnetothermoelastic responses and perturbation of the magnetic field vector in the orthotropic thick hollow cylinder is described. The present method is suitable for orthotropic thick hollow cylinders placed in an axial magnetic field with arbitrary thermal and mechanical boundary conditions. Finally, numerical examples are carried out and discussed.

• Smart Structures and Systems
• /
• v.17 no.2
• /
• pp.327-345
• /
• 2016

The existence of SH-wave in a piezomagnetic layer overlying an initially stressed orthotropic half-space is investigated. The coupled of differential equations are solved for piezomagnetic layer overlying an orthotropic elastic half-space. The general dispersion equation has been derived for both magnetically open circuit and magnetically closed circuits under the four types of boundary conditions. In the absence of the piezomagnetic properties, initial stress and orthotropic properties of the medium, the dispersion equations reduce to classical Love equation. The SH-wave velocity has been calculated numerically for both magnetically open circuit and closed circuits. The effect of initial stress and magnetic permeability are illustrated by graphs in both the cases. The velocity of SH-wave decreases with the increment of wave number.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.13 no.4
• /
• pp.595-603
• /
• 1989

Free vibration of orthotropic laminated composite conical shells with constant thickness are considered. Governing frequency equations are derived based on the Flugge theory and Galerkin method is applied for the numerical analysis. Comparisons are made between present results and others for the isotropic conical shells and numerical results are obtained based on these results for the specially orthotropic laminated composite conical shells with simply supported edges. Variations of frequency parameter on the change of material properties, stacking sequences, stacking number, geometrical parameters and orthotropic parameters are considered in the analysis.