• Aerospace Engineering and Technology
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• v.13 no.1
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• pp.20-26
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• 2014

In this paper, yield stress, tangent modulus and failure strain were varied to ascertain the influence of impact response such as impact force histories and residual energy. And the buckling behavior of FML(Fiber Metal Laminates) were analyzed using numerical method. A number of analyses on FML and aluminum panel were conducted for shear and compression loading to compare the capability of stability. And to evaluate the static performance, static analysis has performed for box beam structure. Low-velocity impact analysis has performed on FML made of aluminum 2024 sheet and glass/epoxy prepreg layers. And the buckling and static performance of FML have been compared to aluminum using the analysis results. For the comparison of structural performance, similar analyses have been carried out on monolithic aluminum 2024 sheets of equivalent weight.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.3
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• pp.735-750
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• 1991

본 연구에서는 적층 복합판의 충격 해석을 위하여 Reddy의 고차 전단 변형 이 론에 기초를 두고, 정적 압입 실험에 의한 접촉 법칙을 고려한 동적 유한 요소 해석 (dynamic finite element analysis)을 행하여 충격 실험에 의한 결과와 1차 전단변형 이론에 의한 해와 비교 검토하므로서, 그 유용성과 우수성을 입증하고, 적층 복합재의 충격 응력 및 응력파 전파 특성에 대하여 연구하고자 한다.

• Composites Research
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• v.16 no.4
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• pp.66-73
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• 2003

The importance of understanding the response of structural composites to impact and CAI cannot be overstated to develop analytical models for impact damage and CAI strength predictions. This paper presents experimental findings observed from quasi-static lateral load tests, low velocity impact tests. CAI strength and open hole compressive strength tests using 3 mm thick composite plates($[45/-45/0/90]_{3s}$- IM7/8552). The conclusion is drawn that damage areas for both quasi-static lateral load and impact tests are similar and the curves of several drop weight impacts with varying energy levels(between 5.4 J and 18.7 J) follow the static curve well. In addition, at a given energy the peak force is in good agreement between the static and impact cases. It is identified that the failure behaviour of the specimens from the CAI strength tests was very similar to that observed in laminated plates with open holes under compression loading. The residual strengths art: in good agreement with the measured open hole compressive strengths. considering the impact damage site area, an equivalent hole. The experimental findings suggest that simple analytical models for the prediction of impact damage area and CAI strength can be developed on the basis of the failure mechanism observed from the experimental tests.

• Composites Research
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• v.16 no.1
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• pp.50-57
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• 2003

Usually many researchers have used the modified Hertzian contact law or experimental static indentation law to analyze impact response of composite laminates subjected to the low-velocity impact. In this study, physical meaning of the method using the laws was investigated and the difference between the analytical results obtained using the laws was also investigated. Furthermore parametric study on contact constant and exponent in the contact law was performed. Finally it was shown that a linearized contact law can be well applied to low-velocity impact response analysis of composite laminates. If this concept is used, commercial finite element software can be used to solve impact problem without making any auxiliary code.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.1
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• pp.9-19
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• 1989

The impact stress and wave propagation of graphite/epoxy and glass/epoxy laminates subjected to the transverse low-velocity impact of steel balls are investigated theoretically. A plate finite element model based on Whitney and Pagano's theory for the analysis of heterogeneous and anisotropic plates taking into account of the transverse shear deformation is used for the theoretical investigation. This model is in conjuction with static contact laws. The basic element is a four-node quadrilateral with the five degrees-of-freedom per node. The reduced integration technique is used for shear locking associated with low-order function in application to thin plates. These two materials are composed of [0.deg./45.deg./0.deg./-45.deg./0.deg.]$_{2S}$ and [90.deg./45.deg./90.deg./-45.deg./90.deg.]$_{2S}$ stacking sequences and have clamped-clamped boundary conditions. Finally, the present results are compared with an existing solution and wave propagation theory and then impact stress and wave propagation phenomena are investigated.gated.

• Elastomers and Composites
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• v.35 no.2
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• pp.138-148
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• 2000

In order to investigate the possibility of EPDM micro cellular pad (MCP) as an impact sound insulation product, we studied static/dynamic properties and vibration transfer characteristics of EPDM MCP depending on shape, thickness, degrees of foaming by using material test system (MTS) and lab scale mock-up test apparatus. Static/dynamic rigidity is increased when shape is simple. thickness and degrees of foaming low. We could see that dynamic stiffness is proportional to the transmissibility of EPDM MCP. When dynamic stiffness is increased, characteristic peak at transmissibility curve moves high frequency range or snows increase of maximum value of transmissibility. For lab scale mock-up test and finite element method, EPDM MCP shows low vibration velocity and superior mode shape to just concrete plus slab structure. We could confirm that possibility of EPDM MCP as a impact sound insulation product is high.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.2
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• pp.87-94
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• 1999

The Morison's formula has been commonly used in the determination of wave forces of sinusoidal waves acting on coastal or ocean structures of pile-supported type. In the case that plunging breakers are incident, the structures are subjected to impulsive breaking wave forces which are normally much larger than the Morison's. However, the impulsive breaking wave forces act in a very short time, and hence a dynamic structural analysis should be done to determine whether or not to include the forces in the design force items. In the present study, numerical methods for calculating the dynamic response of a vertically located cylindrical pile are developed. Static and dynamic displacements are then compared through several example analyses varying the structural properties of pile.

• Journal of Korean Society of Steel Construction
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• v.10 no.2 s.35
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• pp.187-199
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• 1998

The highspeed railway bridge which support continuous and high moving mass evalute the dynamic state and make the displacement of the bridge makes more or less, but up to this time the bridges are designed by the static design concept. for example when we design bridge we use impact factor, which only times the static load makes dynamic load. But becouse it simples. it can't express all of the effects. And so, in this report we study the modeling method of the moving mass and the dynamic factor.

• Computational Structural Engineering
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• v.10 no.3
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• pp.145-155
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• 1997

In this study, static and dynamic transient analysis of tracked vehicle structure with recoil impact load is performed for transient impact and traveling load using ANSYS and ABAQUS FEM codes. When transient impact loads are applied at tracked vehicle, the maximum dynamic Von Mises stress occurs between beam stiffener of upper plate and race ring and stress level is about 390-450 MPa. The results of transient analysis shows similar level and tendency with static stress with dynamic force effect of 1.6. The excessive stresses occur around the race ring for the both cases. When the traveling loads are applied on the tracked vehicle, the maximum Tresca stress occurs around suspension #1 and is about 450 MPa and results of static and nonlinear transient analysis are quite similar.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.7
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• pp.465-470
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• 2022

This paper studied the high-velocity impact behavior characteristics of metal materials by crosschecking the high-velocity impact analysis with the high-velocity impact experiment results of aluminul 6061. The coefficients of the Huh-Kang material model and the Johnson-Cook fracture model were calculated through quasi-static using MTS-810 and dynamic experimenting using the Hopkinson bar equipment for high-velocity impact analysis. The penetration velocity and shape were predicted through high-velocity impact analysis using the LS-DYNA. The resultes were compared with the experiment results using a high-velocit experiment equipment. It is intended to be used the containment evaluation research for aircraft gas turbine engine blade.