• 대한기계학회논문집A
• /
• 제37권2호
• /
• pp.187-192
• /
• 2013

피라미드형 금속 내부구조체를 가진 얇은 금속 샌드위치 판재는 외판들과 내부구조체를 연속적 프로젝션 용접하여 제작한다. 이 용접공정에서 발생하는 용접압력 때문에 내부구조체의 변형에 의한 내부구조체의 결함이 발생한다. 내부구조체의 결함은 저속 충격하중이 부가된 얇은 금속 샌드위치 판재의 응답에 영향을 미친다. 이 논문에서는 피라미드형 금속 내부구조체를 가진 얇은 금속 샌드위치 판재의 지배적인 결함 모드를 도출하고자 한다. 3 차원 유한요소해석을 통하여 여러가지 결함모드에 대한 얇은 금속 샌드위치 판재의 충격 응답 변화를 고찰하였다. 또한 유한요소해석 결과와 낙하 충격시험 결과를 비교/분석 하였다. 이 결과로부터 피라미드형 금속 내부구조체를 가진 얇은 금속 샌드위치 판재의 지배적인 결함모드를 4 개 지주들에 대칭 결함이 적용된 전방형 대칭 결함모드로 선정하였다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2009년도 춘계학술대회 논문집
• /
• pp.167-168
• /
• 2009

• 한국생산제조학회지
• /
• 제21권4호
• /
• pp.547-555
• /
• 2012

This paper focuses on the research of the anode and cathode in the Ni-MH secondary battery. In this paper, the proposed method employs a continuous wave Nd : YAG laser based on the pure Ni instead of the low carbon steel to improve the conductivity although the conventional secondary battery is based on the resistance spot welded with low carbon steel SS41. It welds a sandwich panel using the pure Ni and the porous thin plate, and the tested optimal conditions for the laser power and irradiation speed were 300 and 350 Watt, and 1.0~1.6m/min, respectively. Finally, we observed a ratio, heat input and cross-section and measured the conductivity of the welding section to test the weldability.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2011년도 춘계학술대회 논문집
• /
• pp.1301-1302
• /
• 2011

• Advances in materials Research
• /
• 제6권4호
• /
• pp.317-328
• /
• 2017

In this paper, an improved theoretical solution for interfacial stress analysis is presented for simply supported concrete beam bonded with a sandwich FGM plate. Interfacial stress analysis is presented for simply supported concrete beam bonded with a sandwich plate. This improved solution is intended for application to beams made of all kinds of materials bonded with a thin plate, while all existing solutions have been developed focusing on the strengthening of reinforced concrete beams, which allowed the omission of certain terms. It is shown that both the normal and shear stresses at the interface are influenced by the material and geometry parameters of the composite beam. A numerical parametric study was performed for different simulated cases to assess the effect of several parameters. Numerical comparisons between the existing solutions and the present new solution enable a clear appreciation of the effects of various parameters. The results of this study indicated that the FGM sandwich panel strengthening systems are effective in enhancing flexural behavior of the strengthened RC beams.

• Steel and Composite Structures
• /
• 제45권5호
• /
• pp.767-774
• /
• 2022

A geometrically nonlinear stability analysis of sandwich annular plates with cellular core and particle-reinforced composite layers has been performed in the present research. The particles are powders of graphene oxide (GOP) which act as nanoscale filler of epoxy matrix. To this regard, Halpin-Tsai micromechanical scheme has been used to define the material properties of the layers. A square shaped core has been considered for which the material properties have been defined based on the relative density concept. Large deflection theory of thin shells has been selected to develop the complete formulation of sandwich plate. The geometrically nonlinear stability analysis of sandwich annular plates has been carried out by indicating that the buckling load is dependent on particle amount, thickness of layer and core relative density.

• Coupled systems mechanics
• /
• 제13권2호
• /
• pp.133-151
• /
• 2024

In this paper, an improved theoretical interfacial stress analysis is presented for simply supported composite aluminum- sandwich honeycomb beam strengthened by imperfect FGM plateusing linear elastic theory. The adherend shear deformations have been included in the present theoretical analyses by assuming a linear shear stress through the thickness of the adherends, while all existing solutions neglect this effect. Remarkable effect of shear deformations of adherends has been noted in the results.It is shown that both the sliding and the shear stress at the interface are influenced by the material and geometry parameters of the composite beam. This new solution is intended for applicationto composite beams made of all kinds of materials bonded with a thin plate. Finally, numerical comparisons between the existing solutions and the present new solution enable a clear appreciation of the effects of various parameters.

• 대한조선학회논문집
• /
• 제32권4호
• /
• pp.87-96
• /
• 1995

본 연구에서는 샌드위치 평판이 2축 압축력을 받아 면재와 심재가 전체적으로 좌굴되는 경우를 Rayleigh-Ritz 법으로 해석하였다. 샌드위치 평판의 전체좌굴강도에 대한 경계조건의 영향을 검토하기 위하여 단순지지, 고정 및 이들의 조합상태에 놓인 평판을 고려하였으며, 심재 및 면재의 구조특성에 따른 좌굴강도의 변화도 고찰하였다.

• Advances in nano research
• /
• 제13권5호
• /
• pp.427-435
• /
• 2022

Static stability behaviors of annular sandwich plates constructed from two layers of particle-reinforced nanocomposites have been investigated in the present article. The type of nanoscale particles has been considered to be graphene oxide powders (GOPs). The particles are assumed to have uniform and graded dispersions inside the matrix and the material properties have been defined according to Halpin-Tsai micromechanical model. The core layer is assumed to have honeycomb configuration. Annular plate has been formulated according to thin shell assumptions considering geometrical nonlinearities. After solving the governing equations via Galerkin's technique, it is showed that the post-buckling curves of annular sandwich plates rely on the core wall thickness, amount of GOP particles, sector radius, and thickness of layers.

• 대한조선학회논문집
• /
• 제33권3호
• /
• pp.56-65
• /
• 1996

최근 재료 과학의 발달과 함께 선박의 초고속화를 추구함에 따라 높은 강도와 중량의 경량화를 동시에 만족시킬 수 있는 복합 재료에 대한 요구가 증대되고 있다. 샌드위치 구조 형식은 두껍고 약한 저밀도의 심재와 얇고 강한 고밀도의 면재가 접착된 복합 구조의 한 형태로서 두 개의 면재가 중립 축으로부터 멀리 떨어지게 됨으로써 2차 모멘트가 크게 되어 구조의 강성을 증가시킬 수 있는 가장 효과적인 경량의 구조 형식이다. 본 연구에서는 샌드위치 평판 구조가 분포 하중, 압축 하중, 전단 하중 및 이 들의 복합하중을 받을 때의 응력 및 좌굴 하중을 Rayleigh-Ritz법을 이용하여 정밀 해석하였다. 그리고, 샌드위치 평판에 대한 초기 설계에 응용이 가능하도록 좌굴응력 외에 Wrinkling 응력에 관한 제한조건을 고려하여 샌드위치 평판의 최소 중량 설계를 수행하였다.