In order to provide the basis data for broad use and safe design of carbon fiber reinforced plastic, this paper aims at investigating the fracture behavior on CFRP specimen composed of one directional fiber through three point bending test. On the basis of experimental result, the improvement of composite layer specimen can be secured with the other data to compare the existing specimen. The fracture behavior happened at the experimental procedure is investigated in this study. The maximum loads of 1200 N, 1700N and 1600N are shown respectively at the specimens with the layer angles of 30°, 45° and 60°. The highest load is shown at the layer angle of 60° among all specimens and the longest displacement is maintained until each of the layer structure is broken down. The fracture due to the force applied from the outside can be prevented by applying the result of this study to the real structure. As structural safety can be evaluated and anticipated through this study, it is thought that the safe design is devoted.

In this study, the buckling restoration at CFRP 3-Point bending specimen composed of 30°, 45°and 60° is investigated when the pressure at the lowest position on the compressed specimen is eliminated. The fracture configuration and stress contour of the specimen can be seen according to the laminate angle of fiber. The result of this study is thought to apply the data for the safe design of CFRP structure.

This study investigates the safety and life during the fatigue load by the configuration of seat frame. On back frame at seat frame, the life and damage are analyzed. The deformation and equivalent stress are compared with each other through the vibration analysis, The result of this study through the analysis can be applied to develop the automotive seat frame with durabilty and safety.

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.

An aluminum with the light weight has been used at the automotive car body. As the aluminum is applied to the automotive seat, the optimum design becomes important by investigating the mechanical properties. This study aims at suggesting the basic data for the optimum design of automotive seat frame. In this study, the mechanical properties are investigated through the simulation analysis on the entire structure of seat frame. Two study models using the real commercial vehicles are designed with CATIA program and analyzed with ANSYS program. The harsh condition during the driving state is supposed by using the analyses of natural frequencies and harmonic responses. As the real frequency ranges in this study are set by selecting the natural frequencies through modal analysis. The critical frequencies are analyzed by harmonic response on which the driver is seated. The values of maximum equivalent stresses at models 1 and 2 are shown to be 18.073MPa and 2259.2MPa respectively. The critical frequency at models 1 and 2 are also shown to be 77 Hz and 206 Hz. The maximum stress at model 1 becomes far bigger than model 2. By comparing two models, model 1 has more critical condition than model 2. At the design of automotive seat frame at the dynamic vibration condition, the material of design with the durability and safety can be secured through this study result.

CFRP hardened by carbon fiber and resin has the property of high strength and low weight. Specifically, the strong feature against the external vibration environment is shown as CFRP is designed with the structure of multi-axes. So, CFRP in place of metal has been used at the various fields. CFRP specimens for mode Ⅱ are applied with the repetitive fatigue load in this study. These specimens have the fiber layer angles of 30°, 45° and 60°. The material properties of specimens are investigated with the result of fatigue fracture due to this load. As the study result, the smallest and largest reaction forces of 500 N and 540 N are shown at the layer angle of 30° and 60° respectively among these specimens. The separation of adhesive interface at 4000 fatigue cycles is happened earliest in case of the layer angle of 60°. But the separation of adhesive interface at 11000 fatigue cycles is happened latest in case of the layer angle of 45°. Through the result of fatigue property, it is thought that the basis data can be applied to evaluate the safety at CFRP structure applied with fatigue.

Separately from a single body, crash box is maufactured into the two alumnae by bonding adhesive. Crashbox has the property to absorb the shock by impact transferred to the car body at the collision between cars. In this study, the structural effect and performance are investigated according to the positions of holes punched at this crash box. The optimal structure is investigated for optimal design data of aluminum crash box. The equivalent stresses of study models distributed by compressive loads are compared with each other by using the analysis program of ANSYS. Total energies and mechanical strengths of study models at the real situation are also analyzed. As analysis results, the maximum equivalent stresses of 40880MPa, 42368MPa, 43176MPa, 44960MPa and 43476MPa are shown at study models due to the hole positions of 10mm, 15mm, 20mm, 25mm and 30mm from the upper plane of crash box respectively. Also, the total energy on analysis are verified within the error range of 10 % by comparing that on experiment at the hole position of 10mm. It is thought that the crash box due to the hole position from the upper plane of crash box can be effectively designed through this study result.

As CFRP with only a single material shows the various fracture properties, it has been applied to the many areas through the whole industry. The method bonding with adhesive has been recommended to apply the CFRP to structure. But it is inevitable that the mechanical joints with bolt, nut and rivet have been used sometimes. This study investigates the effect that these joints influence the CFRP panel through the analysis result. The analysis models as CFRP panels with the thickness of 5 mm have four kinds of layer angles which are 30°, 45°, 60° and 75°. The fracture property is examined when the pressure by the mechanical joint is applied to the upper panel. As the joint pressure is distributed most effectively in case of the layer angle of 60°, it is shown that this pressure becomes lower and the deformation of panel becomes lowest. On the basis of this study result, it is thought that the foundation data for the design of CFRP structure can be provided and contributed to the safety design of structure.

In this study, the analyses of structure, fatigue and vibration with two models of 1 and 2. As the result of structural analysis, the equivalent stress and the total deforamtion of model 1 become higher than those of model 2.Model 1 shows fatigue life more than model 2. As the vibration analysis, model 1 has the safety better than model 2. As shown by these results, the main parts ofdamage and the weak areas can be investigated to differ from each other according to the configuration of model though these models have the same material property. The result of this study through the analysis can be applied to develop the optimal design of automotive seat frame with durabilty and safety.

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.

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.

This study aims at analyzing the property of the structural body bonded with alumimum foam by the utilization of the aluminum foam of closed type used generally with impact absorbent. The structural bodies bonded with the aluminum foam of DCB and TDCB are designed in this study, and then the fatigue analysis and experiment are carried out. At fatigue analysis, the maximum load happens at all of each specimen models when the fatigue life of 0 to 50 cycle is proceeded. And from the point of time that the maximum load happens, the load at the bonded surface is seen to be decreased in cases of analysis and experiment. As the specimen thickness is increased, the maximum load happened at specimen is increased. It is confirmed that the result of fatigue analysis becomes similar to that of fatigue experiment for verification. It is thought that the study data on various specimen thicknesses can be secured simply without the extra fatigue experimental procedure. By using this study result, the mechanical properties of the structural bodies bonded with the alumimum foams of DCB and TDCB with mode Ⅲ type 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.

Nowadays, the study of CFRP reinforced with carbon fiber is focused on improving the the mechanical property. The study on the fracture data of CFRP are not properly made out than that of the general mechanical joint. In this study, the fracture property of mode 1 at the same condition of tensile experiment is investigated by applying the layer angle to laminated CFRP with the thickness of 15 mm. When the reaction forces until dropping out the bonded surface are compared with the cases of the layer angles of 0°, 45° and 60°, the reaction force is shown to be most and the elapsed time until dropping out the bonded surface is longest at that of 45°. The deformation energy is also shown to have the highest value by dropping out the adhesive interface. As the basis of the analysis result of this study, the most safety with fracture resistance is shown in the case of 45°. the bonded structure applying the appropriate layer angle is thought to have the structural safety.

CFRP has the high strength and low weight. But it tends to be frail if it is applied with the mechanical bonding method using weld, rivet or bolt. So, the chemical bonding method using the special adhesive has been utilized. By applying the bonding method with the adhesive, this paper investigates the mechanical property of DCB specimen bonded with the type of mode 2 through the simulation analysis. Four kinds of specimen thicknesses are 25mm, 35mm, 45mm and 55mm in this study. The mechanical behaviors of specimens due to the forced displacements are investigated as the distributions of equivalent stresses. The reaction force becomes higher as the specimen thickness is increased. The result of this study about the fracture property of adhesive joint is thought to be contributed to the safe design of structure with CFRP.

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.