Light weighting is one of techniques considered importantly at designing the mechanical structure using the light weight material. This study deals with aluminum-6061 and aluminum foam which stood in the spotlight of light weight material. And the finite element method for safety evaluation has been carried out in order to prevent from the damage and fatigue fracture due to crack appearing at the mechanical structure with this material. The simulation analysis as MT(middle tension) test was carried out by using the core of aluminum foam and the material laminated with sandwich structure of Al-6061. The mechanical structure is linked together with various parts and designed as the material with hole or crack. So, MT test is one of the test methods to evaluate the fatigue fracture characteristic of material and the strength inside material with the center crack by applying the load to the part connected pin. The real material strength is thought to be evaluated through the study result of MT test analysis.

In this study, the fracture property of the bonded structure with aluminum foam is analyzed by using the closed aluminium foam for impact absorber. DCB and TDCB specimens manufactured with the single lap joint method of mode 3 are designed by varying the thickness. The static analysis through ANSYS finite element program is carried out on the specimen model due to each thickness. Also, the static experiment is performed in order to verify the analysis result. This study aims at comparing the shear strengths of the bonded structures of DCB and TDCB made with aluminum foam and investigating the mechanical properties.

As a part of light weight, the adhesive has been applied to joint the mechanical structure. The porous material is used with aluminum foam in case of the structure bonded with only adhesive. In order to confirm the durability, it is necessary to investigate the fracture toughness at the bonded joint. So, the fracture property at joint interface of aluminum foam different from the non-porous material becomes especially important. In this study, the tapered double cantilever beams(TDCB) with the type of mode Ⅲ are manufactured with aluminum foam. The fracture toughness at the joint of the structure bonded with only a adhesive can be obtained. The static analyses are carried out and verified the results by the experiment. As the results of static analyses, the reaction forces ranged from 0.30 to 0.41 kN at all specimens are shown when the forced displacements are proceeded as much as 7 to 9 mm. As the results of analyses and experiments are compared with each other, there is a little bit of difference between these results. Through the result of this study, the mechanical properties at TDCB specimens with the type of mode Ⅲ can be understood.

In this study, the fracture property of impact absorption is investigated using the carbon fiber composite material. And this property is compared with the carbon fiber composite material with aluminum foam. Carbon fiber composite material has the high specific strength and rigidity and the superior durability and fatigue life and light weight. On the ground of these properties, this material has been used widely at the fields of airplane, national defence industry, vehicle and the various industrial areas. Aluminum foam can also be applied at the various areas as it is the material with the superior properties. And this foam is the material which can solve the problem on the light weight of particular product. At the condition of the impact energy of 20J, the maximum loads of CFRP sandwich composite and CFRP sandwich composite with aluminum foam core are shown to be 5.7 kN and 6.5 kN respectively. In case of maximum energies, these values are shown to be 19 J and 17.5 J respectively. At the impact energy of 50 J, the maximum loads of CFRP sandwich composite and CFRP sandwich composite with aluminum foam core are shown to be 7 kN and 8.8 kN respectively. In case of maximum energies, these values are shown to be 43 J and 48 J respectively. At the impact energy of 80 J, the maximum loads of CFRP sandwich composite and CFRP sandwich composite with aluminum foam core are shown to be 9.2 kN and 11 kN respectively. In case of maximum energies, these values are shown to be 70 J and 63 J respectively. As the result of this study, the mechanical properties are investigated through the impact experiments on the composites composed of the closed aluminum foam and the carbon fiber reinforced plastic used frequently as absorbents.

The simulation analysis about the mechanical behavior by thickness on the compression procedure of the bonded aluminum foam is carried out in this paper. The maximum equivalent stress is increased very rapidly at three models. This stress approaches the yielding point when the compressive displacement is proceeded as much as 6mm. After yielding point, this stress approaches the maximum point. A value of this stress is about 1.0MPa. The reaction force approaches the maximum point when the compressive displacement is proceeded as much as 6mm. These reaction forces are shown to be 3000N, 5000N, 7100N respectively at the specimen thicknesses of 15, 25 and 25 mm. The maximum deformation energy is abruptly increased from the displacement of 6 mm and the compressive energy in case of the specimen thickness of 15 mm is shown to highest among three specimens when the displacement is proceeded as much as 13 mm. The experiment with the case of specimen thickness of 25mm is carried out in order to verify these analysis results. The mechanical properties of the bonded structures composed of aluminum foams can be thought to be analyzed effectively.

Because aluminum foam is porous material, the frature property is different from that of non-porous material. This aluminum foam can be used with the joint bonded with adhesive in order to utilize the light weight to the maximum. So, the study of fracture property on bonded surface can be important. In this study, the analyses on the specimens with two kinds of configuration as DCB(Double Cantilever Beams) and TDCB(Tapered Double Cantilever Beams) aluminum foams of mode Ⅲ type bonded with adhesive are carried out and compared with each other. And the fracture properties the adhesive surfaces of the structure with bonded aluminum foams are studied as the static experiments on these verifications are done. DCB and TDCB specimens used in this study have the variable of thickness(t) as 35mm, 45mm and 55mm. As the result of this study, the range of reaction forces are 0.3 to 0.8 kN and 0.5 to 1.2 kN at DCB and TDCB specimens respectively. The results of the static experiments can also be confirmed with these similar results. These study results can be obtained by only a simulation without the special experimental procedures. The mechanical properties of the bonded structures composed of DCB and TDCB aluminum foams with mode Ⅲ type can be thought to be analyzed effectively.

This study investigates the mechanical behavior at the compression of bonded aluminum foam. Four kinds of specimen thicknesses are 25, 50, 75 and 100mm. These aluminum foams are compressed with the speed of 5mm/min. The reaction forces in cases of 25, 50, 75 and 100mm are 2510, 5080, 7700 and 10400N respectively. The equivalent stresses are 0.96, 1.00, 1.02 and 1.03MPa respectively. These analysis results are verified by comparing with the experimental results. The results of this study can be contributed to the safe design of structure.

As a part of light weight, the adhesive has been applied to joint the mechanical structure. The porous material is used with aluminum foam in case of the structure bonded with only adhesive. In order to confirm the durability, it is necessary to investigate the fracture toughness at the bonded joint. So, the fracture property at joint interface of aluminum foam different from the non-porous material becomes especially important. In this study, the static facture analysis was carried out with DCB specimen bonded with adhesive as the loading type of mode Ⅲ. The thicknesses of specimens are 35, 45 and 55 mm. When the forced displacements 5 mm applied on the specimen proceed at specimen thicknesses of 35, 45 and 55 mm, the maximum stresses is shown to be happened at the range from 3.3 MPa to 3.6 MPa. The maximum equivalent stress happened at the specimen thickness of 35mm becomes highest among four kinds of specimens. The static experiment is carried on in order to verify these analyses representatively. As the experimental data become similar with the simulation data, it is thought that these analysis data can be applied at analyzing them into the adhesive joint of real porous material.

As the property of the aluminum foam with porosity, the effect of impact is distributed through the distortion of each lattice like honeycomb at impact. So, this porous aluminum foam is widely used at the crash box or the impact absorber guard rail to prevent the damage. In addition, there is a property of low weight by the chemical bonding using the adhesive. As this study investigates the distortion property of the aluminum foam bonded with adhesive, the fracture property and the stress distribution of the bonded interface are examined. The specimen thicknesses are 25, 35, 45, 55 and 65 mm. And the torsional moments corresponding to 100, 200 and 300 J are applied at one side of bonded aluminum foam. The mechanical behaviors at the bonded interface and the fixed part are also investigated. It can be seen that the minimum specimen thickness must become 55 mm and over in order to maintain the bonding force due to the applied impact energy. The analysis result of this study at the bonded interface effected on impact can be effectively applied into the safe design of the structure with the bonded aluminum foam.

An aluminum foam is the super light metal which can be adjusted with the adhesive by using the joint method. In this study, the tapered double cantilever beams(TDCB) with the type of mode Ⅲ are manufactured with aluminum foam. The fracture toughness at the joint of the structure bonded with only a adhesive can be obtained. The static analyses are carried out and verified the results by the experiment. As the results of static analyses, the reaction forces ranged from 0.30 to 0.41 kN at all specimens are shown when the forced displacements are proceeded as much as 8 to 9 mm. The tapered double cantilever specimen for mode Ⅲ with the thickness of 55 mm is carried out by the static experiment representatively to verify the analysis results. As the results of analyses and experiments are compared with each other, there is a little bit of difference between these results. So, the simulation results of this study can be thought to be confirmed. It is thought that even the only analysis data omitting the extra experimental procedure can be verified in order to use the data practically. Through the result of this study, the mechanical properties at TDCB specimens with the type of mode Ⅲ can be understood.

As a part of light weight, the adhesive has been applied to joint the mechanical structure. The porous material is used with aluminum foam in case of the structure bonded with only adhesive. In order to confirm the durability, it is necessary to investigate the fracture toughness at the bonded joint. So, the fracture property at joint interface of aluminum foam different from the non-porous material becomes especially important. In this study, the static facture analysis was carried out with DCB specimen bonded with adhesive as the loading type of mode Ⅲ. The thicknesses of specimens are 35, 45 and 55 mm. When the forced displacements 5 mm applied on the specimen proceed at specimen thicknesses of 35, 45 and 55 mm, the maximum stresses is shown to be happened at the range from 3.3 MPa to 3.6 MPa. The maximum equivalent stress happened at the specimen thickness of 35mm becomes highest among four kinds of specimens. The static experiment is carried on in order to verify these analyses representatively. As the experimental data become similar with the simulation data, it is thought that these analysis data can be applied at analyzing them into the adhesive joint of real porous material.

As aluminum foam has the most superior absorption of impact energy, this material has been used at automobile and airplane. If aluminum foam is used by jointing bolt and nut, it can be broken. Therefore, it is more effective to bond aluminum foam and other materials by adhesive. In this study, the fatigue fracture simulation through ANSYS program is carried out on the aluminum foam specimen bonded with adhesive as the type of DCB Mode Ⅲ. There are four kinds of specimens with the types of DCB Mode Ⅲ in this study. The thicknesses of four specimens are 35mm, 45mm, 55mm and 65mm. In cases of specimen thicknesses of 35mm, 45mm, 55mm and 65mm, the maximum loads are shown as ±0.2kN, ±0.55kN, ±1kN and ±1.2kN respectively. As the specimen thickness increases, the maximum loads increase. The results of fatigue experiment as specimen thickness of 55mm can be shown to approach the simulation results by confirming the simulation results of this study. So, The simulation data can be applied in order to investigate the mechanical property at DCB specimen with the type of Mode Ⅲ.

본 연구에서는 알루미늄 폼을 TDCB 형태의 시험편으로 설계하여 ModeⅡ 조건에서의 정적 거동 실험 및 전단 피로 실험을 통해 평가 및 검토하였다. TDCB 시험편 모델들의 길이와 두께는 각각 200mm 와 25mm이고, 접착면의 각도는 6°에서 12°까지 2° 간격으로 4가지의 모델을 모델링을 하였다. 세 가지 모델의 실험 과정을 데이터화한 그래프들을 비교해 보면 같은 피로하중 조건에서는 모델의 경사진 각도가 클수록 피로하중을 견딜 수 있는 사이클 수가 많은 것을 알 수 있다. 실제 실험에서와 유사한 결과를 보이기 때문에 본 연구에서 수행한 유한요소법 해석 결과에 대한 검증을 할 수 있었고, 이와 같은 방법을 이용하면 많은 비용과 시간이 들어가는 실험 대신에 시뮬레이션만으로도 그 구조적 안전성을 파악할 수 있을 것으로 사료된다.

기계의 무게를 대폭 줄이는 것을 목적으로 복합재료에 대해서 많은 연구를 진행하고 있다. 본 연구에서 탄소 섬유 강화 플라스틱과 알루미늄 폼으로 조합해서 만든 샌드위치에 대해서 압축 시뮬레이션 해석을 하였다. 또한 탄소 섬유 강화 플라스틱의 섬유의 배열방식은 [0/90/90/0]이다. 시뮬레이션 해석 방법은 ANSYS를 이용하여 실제와 같은 경계조건을 주고 유한요소해석을 진행하였다. 시편을 압축하는 동안에 탄소 섬유 강화 플라스틱과 알루미늄 폼이 그 접착력보다 크게 발생되어 떨어지는 형상이 일어났다. 또한 2438.3MPa의 최대 등가응력이 발생된 것을 확인하였다. 본 연구에서 나온 해석결과는 안전설계 및 복합재료의 개발에 필요한 자료를 제공할 수 있을 것으로 사료된다.

The honeycomb aluminum foam of the porous metal has the merit of the impact absorption, the soundproof, the heat conductivity, the light weight. Aluminum 6061-T6 is used at the materials for the automobile, the ship, the machine and various structures. In this study, the sandwich combined with the honeycomb aluminum foam and aluminum 6061-T6 is simulated with the impact. Two kinds of models made by use of CATIA program with 3 kinds of impact energies are analyzed by ANSYS program. As the simulation result, the maximum deformations at the cases of 1 and 2 are shown as 4.8205mm and 11.909mm respectively. And the maximum equivalent stresses at the cases of 1 and 2 are shown as 274.45MPa and 265.6MPa respectively. As the simulation result at case 1 approaches the experimental result, all simulation results can be verified in order to apply into analyzing the impact properties of the honeycomb aluminum foam sandwiches. In cases of three kinds of impact energies, the striker is not shown to penetrate the upper face sheets of case 1. At the impact energy of 100 J, the striker is not shown to penetrate the upper face sheets of case 2. At the impact energies of 200 J and 300 J, the striker is shown to penetrate the upper face sheets of case 2. It is thought to predict and improve the structural safety the composite material combined with the aluminium foam by using this study result.

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.

Recently, the light weight and the safety of automobile are the important targets of automotive design and the parts for car have been substituted the plastic or the porous material for the steel material. As the aluminium foam has many pores at its surface, it has the fatigue property of bonded face which differs from general material. In this study, two dimensional model is designed and performed with the fatigue analysis as the variable(θ value) becomes the slant angle of bonded face at the specimen with the aluminium foam. As the analysis result on the models with the slant angles of 6°, 8° and 10°, the bonding forces are disappeared when the fatigue loads are repeated during 4000 cycle, 4500cycle and 5000cycle respectively. By comparing with the analysis results of three models, the fatigue cycle to endure fatigue load becomes larger as the slant bonded angle becomes higher. So, the structural safety can be seen by applying only as only a simulation of finite element method instead of the experiment where much cost and time is spent. In this study, the configuration of aluminum foam is designed with the shape of TDCB Mode II. The shear fatigue strength of the bonded structure can be evaluated by the analysis program of ANSYS.

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.