• Composites Research
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• v.37 no.3
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• pp.143-149
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• 2024

This paper measures the mechanical properties of corrugated cardboard, an eco-friendly packaging material, and applies these measurements to the MAT_PAPER model in LS-DYNA for finite element analysis. Although MAT_PAPER is primarily designed for modeling the behavior of paper, this research demonstrates its applicability to corrugated cardboard as well. Tensile, compression, and shear behaviors of a corrugated cardboard were measured and analyzed, and based on these results, six yield surfaces were derived and integrated into the MAT_PAPER model. By comparing the finite element analysis of the material tests and the low velocity collapse analysis of the corrugated cardboard square boxes with each experimental results, it was shown that the behavior of corrugated cardboard could be equivalently considered well by the MAT_PAPER model. However, since the model is not rate-dependent, the high strain rate properties of liner materials were measured and used for strain rate correction. Consequently, this matches well with the results of the high-speed compression tests of the corrugated cardboard square boxes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.3
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• pp.271-276
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• 2024

Traditional oil, a depleting resource, accounts for only one-third of the world's oil reserves, so research and cases of utilizing non-traditional oil as a resource are continuously increasing. However, unconventional oil contains bitumen containing solid particles such as sand, and because it is exposed to a high temperature and high pressure environment, deformation can frequently occur in oil pipelines. Therefore, variables such as material, thickness, and angle that can affect the deformation of the oil pipeline were derived and applied to the oil pipeline, and finite element analysis was performed using the Ansys program. As a result of finite element analysis, deformation and maximum load capacity were derived. Afterwards, the same analysis was performed by modeling an optimized oil pipeline by combining the factors with the best deformation resistance and maximum load capacity. As a result of the analysis, the effect of reducing deformation and increasing the maximum load capacity by about 30 % was confirmed, and factors for suppressing deformation when analyzing oil pipelines were derived.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.831-834
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• 2008

The spectral element model is known to provide very accurate structural dynamic characteristics, while reducing the number of degree-of-freedom to resolve the computational and cost problems. Thus, the spectral element model with variational method for an axially moving Bernoulli-Euler beam subjected to axial tension is developed in the present paper. The high accuracy of the spectral element model is the verified by comparing its solutions with the conventional finite element solutions and exact analytical solutions. The effects of the moving speed and axial tension the vibration characteristics, wave characteristics, and the static and dynamic stabilities of a moving beam are investigated.

• Composites Research
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• v.32 no.5
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• pp.206-210
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• 2019

As the use of composite materials of woven structure has expanded to various fields such as automobile and aviation industry, there has been a need for reliability problems and prediction of mechanical properties of woven composites. In this study, finite element analysis for predicting the mechanical properties of composite materials with different weaving structures was conducted to verify similarity with experimental static properties and an effective modeling method was developed. To reflect the characteristics of the weave structure, the meso-scale representative volume element (RVE) was used in modeling. Three-dimensional modeling was carried out by separating the yarn and the pure matrix. Hashin's failure criterion was used to determine whether the element was failed, and the simulation model used a progressive failure model which was suitable for the composite material. Finally, the accordance of the modeling and simulation technique was verified by successfully predicting the mechanical properties of the composite material according to the weave structure.

• Smart Structures and Systems
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• v.8 no.3
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• pp.275-302
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• 2011

This is a review paper on mathematical modeling of actively controlled piezo smart structures. Paper has four sections to discuss the techniques to: (i) write the equations of motion (ii) implement sensor-actuator design (iii) model real life environmental effects and, (iv) control structural vibrations. In section (i), methods of writing equations of motion using equilibrium relations, Hamilton's principle, finite element technique and modal testing are discussed. In section (ii), self-sensing actuators, extension-bending actuators, shear actuators and modal sensors/actuators are discussed. In section (iii), modeling of thermal, hygro and other non-linear effects is discussed. Finally in section (iv), various vibration control techniques and useful software are mentioned. This review has two objectives: (i) practicing engineers can pick the most suitable philosophy for their end application and, (ii) researchers can come to know how the field has evolved, how it can be extended to real life structures and what the potential gaps in the literature are.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.12
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• pp.1931-1936
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• 2004

In this paper, modeling methods for the structural dynamic analysis employing single reference frame are presented and their modal and transient analysis results are compared. The geometric stiffening effects often occur when structures undergo large overall motion. These effects were considered in several structural previous modeling methods but the role of reference frame has never been scrutinized. In this study, modeling methods employing single reference frame are presented, and their numerical results are compared. The results show that discrepancy between the two modeling methods increases as the eccentricity of the structural system and the magnitude of the large overall motion increase.

• Journal of Electrical Engineering and Technology
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• v.6 no.2
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• pp.270-274
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• 2011

This paper presents a parameterized simulation program with integrated circuit emphasis (SPICE) model of a two-level microbolometer based on negative-temperature-coefficient thin films, such as vanadium oxide or amorphous silicon. The proposed modeling begins from the electric-thermal analogy and is realized on the SPICE modeling environment. The model consists of parametric components whose parameters are material properties and physical dimensions, and can be used for the fast design study, as well as for the co-design with the readout integrated circuit. The developed model was verified by comparing the obtained results with those from finite element method simulations for three design cases. The thermal conductance and the thermal capacity, key performance parameters of a microbolometer, showed the average difference of only 4.77% and 8.65%, respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.6
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• pp.51-58
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• 2010

This paper suggests a control technique of the two axes precision stage. The stage is supported by four flexible spring hinges and driven by two piezoelectric actuators. The dynamic motion of the stage is analysed by the finite element method and identified by the frequency domain modeling technique based on the experimental data. The sliding mode control with integrator is applied to improve the tracking ability of the stage to the complex reference input signal. Experimental results demonstrate that the proposed modeling schemes and control algorithm can be used effectively for the two axes stage.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.935-946
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• 2014

This paper investigates the noise transmission performance of industrial mufflers widely used in ships based on the CAE modeling and simulation. Since the industrial mufflers have very complicated internal structures, the conventional Transfer Matrix Method (TMM) is of limited use. The CAE modeling and simulation is therefore required to incorporate commercial softwares: CATIA for geometry modeling, MSC/PATRAN for FE meshing and LMS/SYSNOISE for analysis. Main sources of difficulties in this study are led by complicated arrangement of reactive elements, perforated walls and absorption materials. The reactive elements and absorbent materials are modeled by applying boundary conditions given by impedance. The perforated walls are modeled by applying the transfer impedance on the duplicated node mesh. The CAE approach presented in this paper is verified by comparing with the theoretical solution of a concentric-tube resonator and is applied for industrial mufflers.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.834-839
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• 2004

In this paper, modeling methods for the structural dynamic analysis employing single reference frame are presented and their modal and transient analysis results are compared. The geometric stiffening effects often occur when structures undergo large overall motion. These effects were considered in several structural previous modeling methods but the role of reference frame has never been scrutinized. In this study, modeling methods employing single reference frame are presented, and their numerical results are compared. The results show that discrepancy between the two modeling methods increases as the eccentricity of the structural system and the magnitude of the large overall motion increase.