• Structural Engineering and Mechanics
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• v.55 no.3
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• pp.473-494
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• 2015

A graded harmonic finite element formulation based on three-dimensional elasticity theory is developed for the structural analysis of 2D functionally graded axisymmetric structures. The mechanical properties of the axisymmetric solid structures composed of two different metals and ceramics are assumed to vary in radial and axial directions according to power law variations as a function of the volume fractions of the constituents. The material properties of the graded element are calculated at the integration points. Effects of material distribution profile on the static deformation, natural frequency and dynamic response analyses of particular axisymmetric solid structures are investigated by changing the power law exponents. It is observed that the displacements, stresses and natural frequencies are severely affected by the variation of axial and radial power law exponents. Good accuracy is obtained with fewer elements in the present study since Fourier series expansion eliminates the need of finite element mesh in circumferential direction and continuous material property distribution within the elements improves accuracy without refining the mesh size in axial and radial directions.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.303-310
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• 2003

Small-scale models have been frequently used for experimental evaluation of seismic performance because of limited testing facilities and economic reasons. However, there are not enough studies on similitude law for analogizing prototype structures accurately with small-scale models, although conventional similitude law based on geometry is not well consistent in the inelastic seismic behavior. When fabricating prototype and small-scale model of reinforced concrete structures by using the same material, added mass is demanded from a volumetric change and scale factor could be limited due to size of aggregate. Therefore, it is desirable that different material is used for small-scale models. Thus, a modified similitude law could be derived depending on geometric scale factor and equivalent modulus ratio. In this study, compressive strength tests are conducted to analyze equivalent modulus ratio of micro-concrete to normal-concrete. Equivalent modulus ratios are divided into elastic, weak nonlinear and strong nonlinear phases, which are based on ultimate strain level. Therefore, an algorithm adaptable to the pseudodynamic test, considering equivalent three phase similitude law based on seismic damage levels, is developed. In addition, prior to tile experiment, it is verified numerically if tile algorithm is applicable to the pseudodynamic test.

• Structural Engineering and Mechanics
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• v.76 no.1
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• pp.129-139
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• 2020

In this piece of work, carbon nanotubes motion equations are framed by Kelvin's method. Employment of the Kelvin's method procedure gives birth to the tube frequency equation. It is also exhibited that the effect of frequencies is investigated by varying the different index of polynomial function. By using volume fraction for power law index, the fundamental natural frequency spectra for two forms of single-walled carbon nanotubes are calculated. The influence of frequencies against length-to-diameter ratios with varying power law index are investigated in detail for these tubes. Throughout the computation, it is observed that the frequency behavior for the boundary conditions follow as; clamped-clamped, simply supported-simply supported and these frequency curves are higher than that of clamped-free curves. Computer software MATLAB is utilized for the frequencies of single-walled carbon nanotubes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.12
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• pp.3715-3727
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• 1996

Compression behavior of semi-solid aluminum alloys with controlled solid fractions was investigated in the present study. The stress and strain relationships were obtained from the compression test. Variations of the solid fraction distribution and the material behaviour were investigated for various friction coeffieiants and die speedsd. For a finite element analysis, the semi-solid material was described by a compressible regid viscoplastic model for the solid region and darcy's law for the liquid region. The computed results were compared with experimental data for the validity of the yield criteria.

• Coupled systems mechanics
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• v.12 no.4
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• pp.297-313
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• 2023

This paper deals with delamination analysis of non-linear viscoelastic multilayered beam subjected to bending in the plane of the layers. For this purpose, first, a non-linear viscoelastic model is presented. In order to take into account the non-linear viscoelastic behaviour, a non-linear spring and a non-linear dashpot are assembled in series with a linear spring connected in parallel to a linear dashpot. The behaviours of the non-linear spring and dashpot are described by applying non-linear stress-strain and stress-rate of strain relationships, respectively. The constitutive law of the model is derived. Due to the non-linear spring and dashpot, the constitutive law is non-linear. This law is used for describing the time-dependent mechanical behaviour of the beam under consideration. The material properties involved in the constitutive law vary along the beam length due to the continuous material inhomogeneity of the layers. Solution of the strain energy release rate for the delamination is obtained by analyzing the balance of the energy with considering of the non-linear viscoelastic behaviour. The strain energy release rate is found also by using the complementary strain energy for verification. A parametric study is carried-out by using the solution obtained. The solutions derived and the results obtained help to understand the time-dependent delamination of non-linear viscoelastic beams under loading in the plane of layers.

• Journal of Information Management
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• v.36 no.2
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• pp.153-172
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• 2005

Currently the copyright law and the online digital contents industry development law aim to protect the producers of databases and digital contents. A report on databases in the United States describes that an additional protection of databases is needed as databases get more significant in terms of science and economy and become a key factor on Internet. At this moment, Korea does not recognize the importance of databases of science and technology when we look into any public or civil organizations. Accordingly this paper deals in depth with overall issues surrounding the regal protection of science and technology databases, key contents for science and technology databases protection by current laws, and additional protection problems. Considering that the industry of science and technology databases plays a pivotal role in the securement of national competitiveness, the preparation of legal measures to properly protect databases as one of the policies for the continuing development of databases should not be overlooked.

• Journal of Families and Better Life
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• v.30 no.5
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• pp.59-74
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• 2012

The purpose of this study was to explore the structures of consciousness on the experiences of formation and adjustment in multicultural families. A qualitative study was designed in this article. The research participants were 10 dyads of immigrant married women and their mothers-in-law. Before the marriage, the mother-in-law's expectation about her daughter-in-law was not high, and the daughter-in-law held the same opinion of her mother-in-law. During the marriage process, the mother-in-law had difficulties in terms of physical, emotional, and material aspects. The daughter-in-law endured the wedding procedure by holding onto hope and anticipation for the future. After the marriage, the mother-in-law eventually became satisfied with her daughter-in-law, and the daughter-in-law grew to feel thankful for her new family members and expressed that she was living a happy life. Consequently, the essence of formation and adjustment in multicultural families was "obtaining precious family members through the undergoing of trial and error."

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.1
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• pp.85-96
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• 2004

The purpose of this study is to present the legal object in the related legislation taking the present condition of the domestic laws and the leading cases connected with ecological restoration materials and analyzing their properties according to the analytic standards which are legal class and ecological restoration material items, the present condition by the field of ecological restoration business, interrelationship between the law and the leading cases, comparison of the domestic laws with the foreign regulations. The results of this study are as follows; 1) Detailed enforcement regulation(36.5% of totals), enforcement regulation(32.4%) and law(31.1%) as legal class of the domestic legislation relating to ecological restoration materials are in the order of frequency that shows the little strong frequency at low-ranking class. By items, the number of legislation relating to planting material holds about majority, next to it, stone material, soil material and wood material are in the order of frequency. 2) By the field of ecological restoration business, legislation relating to administration forms the highest frequency(36.3% of totals), next to it, material properties(23.4%), plan design(13.0%) are in the order of frequency. 3) For the number of the leading cases by items of ecological restoration materials, those are, for the most part, them relating to planting material(93.8% of totals). The number of legislation relating to planting material forms the highest frequency at laws and the leading cases in common. 4) The domestic legislation connected with ecological restoration materials is mainly to be in legal class of the positive law, on the contrary, a foreign country has legislation widely consisted of laws, ordinances and other general regulations. Some foreign country legislated the topsoil conservation act, but not to domestic. The result of this study will be applied to legislature and court as reference materials, and to the public and public officer as a means of an understanding of ecological restoration materials.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.71
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• pp.171-194
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• 2016

In the UK, the legal principle for the duty of disclosure established in Carter v Boehm case was codified in the Marine Insurance Act 1906("MIA"). The duty of disclosure under the MIA is the pre-contractual duty by the insured and therefore, the insured should disclose the every material circumstance that would influence a prudent insurer's judgement. If the insured violates the duty of disclosure, the insurer is entitled to avoid the insurance contract, regardless of whether there was the deliberate or reckless breach, which is unfavorable to the insured. The Law Commission reviewed the duty of disclosure under the MIA in detail and provided the Insurance Act 2015 for the purpose of enhancing the interests of the insured. The Insurance Act 2015("Act"),while the basic legal structure of the duty of disclosure under the MIA still remains, amends it in respect of non-consumer insurance and furthermore, integrate the duty of disclosure and the duty not to misrepresent into the duty of fair presentation of risk. And according to the Act, the insurer is required to more actively communicate with the insured before entering the contract with the result that, if the insured fails to disclose the material circumstance but provides the sufficient information to put the insurer on notice, the insurer should further inquire for the purpose of the insured's revealing the material circumstance. In addition, the Act details the insured's constructive knowledge of material circumstance by reviewing the current case law and introduces a new system for the insurer's proportionate remedy against the insured's breach of the duty of fair presentation of risk.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.553-561
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• 2015

The exponential and power law functionally graded material(FGM) theory is reformulated considering the refined shear and normal deformation theory. This theory has ability to capture the both normal deformation effect and exponential and power law function in terms of the volume fraction of the constituents for material properties through the plate thickness. Navier's method has been used to solve the governing equations for all edges simply supported plates on Pasternak elastic foundation. Numerical solutions of vibration analysis of FGM plates are presented using this theory to illustrate the effects of power law index and 3-D theory of exponential and power law function on natural frequency. The relations between 3-D and 2-D higher-order shear deformation theory are discussed by numerical results. Further, effects of (i) power law index, (ii) side-to-thickness ratio, and (iii) elastic foundation parameter on nondimensional natural frequency are studied. To validate the present solutions, the reference solutions are discussed.