The porous metallic material has the most superior physical property and the best mechanical capability. This study is investigated with the simulation analysis by compressing three kinds of specimens. Three aluminum foams with the thickness of 10 mm are bonded at Case 1. Two aluminum foams with the thicknesses of 10 mm and 20 mm are bonded at Case 2. It is one aluminum foam with the thickness of 30 mm at Case 3. The two dimensional model is done by ANSYS design modeler and the finite element analysis is performed by ANSYS structural analysis. As the forced displacement of 1 mm during the elapsed time of 60 sec is applied, the forced displacement of 10 mm during the total elapsed time of 600 sec is applied. As the analysis result, the most reaction force is shown at case 2 among three cases. Case 2 is estimated as the best structure. The analysis result of this study is thought to be the data necessary for the safe design about mechanical structure and the development of composite material.

In this study, the specimen of tapered double cantilever beam(TDCB) with aluminum foam is designed and shearing fatigue strength is based on the investigation of static behaviour analysis under the condition of mode Ⅱ. These specimen models have length and width of 200 mm and 25 mm. The inclined angles of adhesive face at the specimens are 6°, 8 °and 10°. As the inclined angle becomes higher, the time for which the model can not be broken during fatigue load becomes longer. The shearing strength of TDCB bonded structure with aluminum foam applied by shearing fatigue load can be evaluated through finite element method.

In this study, tapered double cantilever beam bonded with aluminum foam composite is modelled and analyzed by finite element analysis. The bonding strength on Mode II of this structure is evaluated and investigated. In cases of inclined angles of 6°, 8° and 10°, maximum equivalent stresses occur 1.29, 1.59 and 2.6 MPa respectively at the range of forced displacement of 5 to 6 mm. And maximum reaction forces become 186, 208 and 235 N individually at this range of displacement in these cases. By the analysis result on 3 kinds of models, the maximum reaction load increases as angle of inclination of model increases. And the elapsed time to approach the maximum load and the time to disappear away become shorter. This study result can be applied into the real composite structure with aluminum foam in case that the surface bonded with adhesive is inclined. This fracture behavior can also be investigated and the impact property can be examined

Britsh StandardBS 7991)에 명시된 DCB 시험편을 본 연구에 맞게 수정 후 두께 25mm, 35mm, 45mm, 55mm, 그리고 65mm의 DCB시험편을 제작하였다. 이 후 시험편을 Single-lap 방식으로 접착한 후 정적실험에서 도출된 최대 전단력을 각 시험편에 10Hz로 피로하중을 가하였다. 실험 결과값에 대한 수치해석적 검증을 하고자 상용 해석 프로그램인 ANSYS를 통해 실험과 동일한 시험편과 조건 하에 해석을 수행하였다. 접착력 해석을 하기 위해서 Mesh의 절점(node)들의 관계가 매우 중요하기 때문에 접착된 부분의 모든 절점들은 동일 선상에 있게 Mesh를 형성하였다. 실험 결과와 해석 결과를 비교해 본 결과 피로하중이 약 200cycle 반복되었을 때 최대 등가응력이 발생 하였고, 이때 전단방향으로 변위가 약 11mm 진전 된 것을 볼 수 있었다. 이후 4000cycle가량 피로하중이 반복 될 동안 변위는 일정하게 점점 증가한 후 피로하중이 약 4800cycle 반복 되었을 때 실험과 해석 데이터 모두 접착계면에서 완전한 전단 파괴가 일어난 것을 볼 수 있었다. 이때 변위는 약 20mm 진행 되었다. 해석을 통해 실험 데이터를 검증해 본 결과 두 결과 값은 완전 하게 같지는 않지만 유한요소법 해석 결과에 대한 신뢰를 확보 할 수 있었다. 이는 실제 구조물에 실험 없이 간단한 재료 물성치만으로도 해석을 통하여 구조적 안전성을 알아 볼 수 있는 한 방법이 될 수 있을 것이라고 사료된다.

Adhesive joint method has been used instead of welding, reveted joint, bolt and nut in various industry fields recently. Aluminum foam has hole or crack on adhesive interface which is different from common composite material. To investigate shear characteristic of adhesive interface between aluminum foams, double cantilever beams(DCB) with thicknesses of 25mm, 45mm and 65mm bonded with single-lab joints are designed. The relation between nodes at finite element model is important to investigate adhesive strength in this study. All meshes are generated and some nodes are located on adhesive zone along collinear axis. As reaction force obtained by static experiment is applied, fatigue analysis is carried with 10Hz. In advance, adhesive property is obtained by preliminary experiment for applying adhesive strength to input into simulation analysis. With these conditions, the analysis results show that 2.97MPa, 3.10MPa and 4.2MPa of maximum equivalent stresses are shown respectively in case model thicknesses are 25mm, 45mm and 65mm. By use of the simulation result at this study, it is possible to find adhesive behavior of aluminum foam and be applied to real adhesive joint structure without experiment by sparing experimental cost and time

알루미늄 폼을 볼트나 너트를 이용하여 체결한다면 경량성이 감소되므로 접착제로 접합하는 것이 가 장 효율적이다. 이런 알루미늄 폼 접착 구조물에 대한 충격 피로 특성과 접착 합면에 대한 파괴인성 연 구는 매우 부족하며 또한 중요하다. 이에 따라 본 연구에서는 알루미늄 폼으로 만들어진 DCB모델을 접 착제로 접합한 후 두께를 변수로 하여 25mm 부터 45mm까지 10mm차이를 두어 실험과 컴퓨터 시뮬레 이션을 통하여 수행하였다. 실험은 MTS사의 인장 시험기를 사용하여 강제 변위 100mm를 주어 변위에 따른 전단력을 알아보았고, 실험과 똑같은 조건하에 ANSYS를 이용하여 유한요소해석을 수행하였다. 실험과 유한요소해석 값을 비교하여 접착제로 접합된 알루미늄 폼 구조물의 접착 합면에 대한 파괴인성을 고찰하였다.

Aluminum foam has many superb properties such as light weight, impact absorption and thermal resistance by comparing with original metallic materials. Composite materials made of aluminum foam have used at various fields as automotive bumper, shock absorption, vessel and aircraft. But it is inefficient to join aluminum foam with bolt and nut because of the property of light weight. In this study, this approach is investigated by joining aluminum foam with adhesive. Impact fatigue and failure toughness at the commissure of adhesive structure are studied by simulation analysis. This study aims to investigate the shear strength evaluation at shear mode of adhesively bonded joint with double cantilever beam(DCB) made of aluminum foam.

four kinds of models designed by the basis of British industrial standard and ISO international standard in this study. Energy release rates at mode 1 are investigated by the fatigue analysis of aluminum foam TDCB model bonded with adhesive. These analysis models are compared each other by classifying four models into m values with 2, 2.5, 3 and 3.5. The value of m as the gradient of model is represented with the function of crack length(a) and height of model(h). Through the correlation relation, the fracture behavior of bonded material is analyzed and these analysis results can be applied to composite structures of various areas. Mechanical property and fracture toughness of composite material are also analyzed in this study.