• Structural Engineering and Mechanics
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• v.38 no.3
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• pp.333-347
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• 2011

This paper shows the solution for an orthotropic disk under the plane strain condition obtained with complex stress functions. These stress functions were induced by Lekhnitskii and expanded by one of the authors. Regarding diametrical compression test, the finite element method poses difficulties in representing the concentrated force because the specimens must be divided into finite elements during calculation. On the other hand, the method shown in this study can exactly represent this force. Some numerical results are shown and compared with those obtained under the plane stress condition for both stress and displacement. This comparison shows that the differences between the tensile stresses occurred under the plane strain condition and also that the differences under a plane stress condition increase as the orthotropy ratio increases for some cases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.3802-3807
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• 2011

In this study, in-plane and out-plane compression tests of aluminum foam and honeycomb sandwich composites were carried out. Through these tests, the relationships of load-displacements were analyzed and the compression characteristics were compared with each other. The specimens were compressed with the speed of 1mm/min by using the universal testing machine. Experimental procedures were taken with photograph by the camera and load cell data were stored into computer. Test results showed that buckling was occurred at the aluminum foam core and honeycomb core according to the increase of load. In the in-plane compression test, the maximum load of aluminum foam specimen was similar with that of honeycomb sandwich. The property of honeycomb was better than that of the foam in consideration of specific gravity. In the out-plane compression test, compression maximum load of aluminum honeycomb sandwich composite was higher than that of aluminum foam sandwich composite.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.535-546
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• 2019

The paper presents a closed-form analytical solution for the ultimate strength of sandwich panels with metal faces and an elastic isotropic core during combined in-plane compression and lateral pressure under clamped boundary condition. By using the principle of minimum potential energy, the stress distribution in the faces during uni-axial edge compression and constant lateral pressure was obtained. Then, the ultimate edge compression was derived on the basis that collapse occurs when yield has spread from the mid-length of the sides of the face plates to the center of the convex face plates. The results were validated by nonlinear finite element analysis. Because the solution is analytical and closed-form, it is rapid and efficient and is well-suited for use in practical structural design methods, including repetitive use in structural optimization. The solution applies for any elastic isotropic core material, but the application that stimulated this study was an elastomer-cored steel sandwich panel that had excellent energy absorbing and protective properties against fire, collisions, ballistic projectiles, and explosions.

• International Journal of Railway
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• v.8 no.2
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• pp.46-49
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• 2015

In this paper, improved out-of-plane design of parabolic arches was proposed based on the current design code. The arches resist general loading by a combination of axial compression and bending actions, and the interaction formula between two extreme cases of axial and bending actions is generally used for the design. Firstly, the out-of-plane buckling strength of arches in a pure axial compression and a pure bending were studied. Then, out-of-plane design of parabolic aches under general transverse loading was investigated. From the results, it can be found that the proposed design equations provided good prediction of out-of-plane strength for parabolic arches which satisfy the thresholds for deep arches, while proposed design equations overestimated the buckling load of shallow arches.

• Journal of Ocean Engineering and Technology
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• v.15 no.1
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• pp.85-91
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• 2001

A study for the structural strength analysis on the doubler plate subjected biaxial in-plane compression and shear load has been performed through the systematic evaluation process. In order to estimate the proper static strength of the doubler plate, non-linear elasto-plastic analysis is introduced. Gap element modeling for contact effect between the main plate and the doubler is prepared and nonlinear analysis procedures are illustrated based on MSC/N4W. In addition, some design guides are suggested through the consideration of several important effects such as corrosion of main plate, doubler width, doubler length and doubler thickness. Finally, theses result are compared with a developed design formula based on the buckling strength and general trends. The design guides, according to the variation of design parameters are discussed.

• Geomechanics and Engineering
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• v.5 no.6
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• pp.499-517
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• 2013

In order to investigate shear behavior of granular materials due to excavation and associated unloading actions, load-controlled plane strain compression tests under decreasing confining pressure were performed under drained conditions and the results were compared with the conventional plane strain compression tests. Four types of granular material consisting of two quartz sands and two glass beads were used to investigate particle shape effects. It is clarified that macro stress-strain behavior is more easily influenced by stress level and stress path in sands than in glass beads. Development of localized deformation was analyzed using photogrammetry method. It was found that shear bands are generated before peak strength and shear band patterns vary during the whole shearing process. Under the same test condition, shear band thickness in the two sands was smaller than that in one type of glass beads even if the materials have almost the same mean particle size. Shear band thickness also decreased with increase of confining pressure regardless of particle shape or size. Local maximum shear strain inside shear band grew approximately linearly with global axial strain from onset of shear band to the end of softening. The growth rate is found related to shear band thickness. The wider shear band, the relatively lower the growth rate. Finally, observed shear band inclination angles were compared with classical Coulomb and Roscoe solutions and different results were found for sands and glass beads.

• Journal of the Korean Society for Heat Treatment
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• v.37 no.1
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• pp.23-28
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• 2024

As global warming accelerates, the transportation industry is increasing the use of lightweight materials with the goal of reducing carbon emissions. Magnesium is a suitable material, but its poor formability limits its use, so research is needed to improve it. Rare-earth elements are known to effectively control texture development, but their high cost limits commercial. In this study, changes in microstructure and texture were investigated by adding Pb, which is expected to have a similar effect as rare-earth elements. The material used is Mg-15wt%Pb alloy. Initial specimens were obtained by rolling at 773 K to a rolling reduction of 25% and heat treatment. Afterwards, plane strain compression was performed at 723 K with a strain rate of 5×10^-2s^-1 and a strain of -0.4 to -1.0. As a result, recrystallized grains were formed within the microstructure, and the main component of the texture changed from (0,0) to (30,26). The maximum axial density was initially 10.01, but decreased to 4.23 after compression.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.609-612
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• 1999

In this paper, we propose wavelet transform image compression method such that an image is decomposed into multiresolutions using biorthogonal wavelet transform with linear phase response property and decomposed subbands are classified by maximum classification gain. The classified data is quantized by allocating bits in accordance with classified class informations within subbands through arbitrary set bit allocation algorithm. And then, quantized data in each subband are entropy coded. The proposed coding method is that the quantized data perform shuffling before entropy coding in order to remove sign bit plane. And the context is assigned by maximum correlation direction for bit plane coding.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.611-616
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• 2000

Numerical studies were carried out to investigate the long-term behavior of late plates in basement, subjected to combined in-plane compressive and transverse loads. For the numerical studies, a computer program of nonlinear finite element analysis was modified by adding function of creep and shrinkage analysis. This numerical method was verified by comparison with the existing experiments. Parametric studies were performed to investigate the strength variations of flat plates with three parameters; 1) loading sequence of floor load, compression and time 2) uniaxial an biaxial compression and 3) the ratio of dead to live load.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.2
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• pp.70-79
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• 1999

The lower ground of structure, in which the strip loads, such as earth dams and embankments , are signiificantly working on , is required to be interpreted as a state of plane strain where the strain of intermediated principal stress direction is put '0' . The plane strain state is frquently observed in actural soil engineering case. For those case, drained stress-strain and strength behavior of Iksan weathered granite soil prepared in cubical specimens with cross-anisotropic fabric was studied by conventional triaxial compression, plane strain and cubial triaxial tests with independent control of the three principal stress. All specimens were loaded under conditions of principl stress directions fixed and aligned with the directions of the material axes. As a result of research , when a ground condition is analyzed under plane strain state, the shear strength obtained from the conventional triaxial compression test can be understimated.