• 대한기계학회논문집A
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• 제33권5호
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• pp.536-543
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• 2009

Dynamic behaviour of a package of a microwave oven under the drop-impact conditions is evaluated by the finite element analysis and tests. PAM-CRASH software is used for the finite element analysis and the tests are performed according to the ISTA(International Safe Transit Association) specification. Results of the analyses are compared with those of the tests and accuracy is shown to be favourable. Under the drop-impact condition of the original design, severe deformation occurs and an improved design is proposed to reduce it. The approach presented in this research can be successfully applied to reduce costs and time required to develop new models of the microwave oven.

• 한국자동차공학회논문집
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• 제5권6호
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• pp.148-154
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• 1997

The safety problems of buses have been arisen due to the increasing of road traffic. Occupant injuries are always possible in the rollover accident and the frontal impact. Thus the structure of bus should have sufficient strength to protect passengers under accidental loads. ECE(Economic Commission for Europe) regulation No.66 prescribes that the superstructure of the vehicle shall be sufficient strength for passengers' surviving and the residual space shall be preserved in the passenger compartment during and after the standard rollover accident situation. Rollover test and simulation on a large-sized bus was completed according to the regulation. The coordinates of the points on the bus were measured by photogrammetry system. The rollover situation was revived by structural crashes simulation software, PAM-CRASH, and it was checked that the structure still complied with the requirements of residual space during rollover situation. The residual space was preserved during rollover, so it was proved that the structure of the investigated bus had much probability of survival in rollover accidents.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.64-71
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• 2009

The development of more safe recliners is an important issue in the automotive industry. However, the development of new recliners is costly and take much time because it is typically based on experimental evaluation using prototypes. This study presents the evaluation of rear crashworthiness for round recliner using finite element method. That reduces the number of repeating test and gives an information about stiffness. To evaluate rear crashworthiness, the FMVSS 301 simulation and pendulum impact simulation were performed. The load path on two simulations was observed and compared each other in this paper. Also stress, strain and internal energy was compared. It is attempted the tooth strength simulation using a substructure option on PAM-CRASH.

• 산업기술연구
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• 제20권B호
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• pp.131-138
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• 2000

In this paper, we would like to develop the bending collapse specific equation of aluminum members which are usually used in light-weight vehicle or electromobiles. The result of the developed equation are compared with that of test and finite element methods as the moment-rotational angle curves. Three types of aluminum members are tested with the pure bending collapse test rig. PAM-CRASH and ABAQUS program are used for finite element analysis. As the result the developed bending collapse governing equation is accurate in estimating the yield moment and the maximum moment. Especially, in the case of the local buckling and the delayed buckling, the developed equation is better effective than F.E.M.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.487-492
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• 2002

In this study, designs of protection fences such as the concrete median barrier and the guardrail were performed. The foreign standard of concrete median barrier was introduced and implemented without modification fitting to domestic vehicles and highway conditions. In a car accident, median barrier doesn't protect vehicles effectively, especially for heavy vehicles such as bus and heavy truck. Guardrail doesn't protect vehicle effectively, either. The purpose of this study is to develop the optimal performance design of concrete median barrier and design of guardrail using the design of experiment as well as crashworthiness analysis which is done by Pam-Crash. As a result of this study, an optimal design of concrete median barrier was obtained considering von Mises stress, volume and COG acceleration of truck. And design of guardrail satisfying the domestic requirements was obtained.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.473-478
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• 2003

The hydraulic buffer stop placed on the end of the railway brakes the train could not reduce the velocity sufficiently because of the braking system troubles or driver's mistakes. The hydraulic buffer stop is composed of 2 operating parts; hydraulic buffers and rail clamps. Hydraulic buffers brake trains non-destructively in low speed, otherwise rail clamps begin to work in higher speed. In this paper, The braking process of the hydraulic buffer stop is investigated by numerical methods. The hydraulic buffer is numerically analyzed and designed to absorb the kinematic energy of the train below 3.2km/h speed. The hydraulic buffer stop crushed by the train with 5km/h speed is analyzed by FEM package-PAM CRASH in order to obtain the stress profile in rail clamps and buffer stop frame.

• 대한치과보철학회지
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• 제43권6호
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• pp.727-735
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• 2005

Statement of problem. Platform switching in implant prosthesis has been used for esthetic and biological purpose. But there are few reports for this concept. Purpose. The purpose of this study is evaluation of platform switching in wide implant by three dimensional finite element analysis. Materials and Methods. The single implant and prosthesis was modeled in accordance with the geometric designs for Osstem implant system. Three-dimensional finite element models were developed for (1) a wide diameter 3i type titanium implant 5 mm in diameter, 13 mm in length with wide cemented abutment, titanium alloy abutment screw, and prosthesis (2) a wide diameter 3i type titanium implant 5 mm in diameter, 13 mm in length with regular cemented abutment, titanium alloy abutment screw and prosthesis(platform switching) was made for finite element analysis. The abutment screws were subjected to a tightening torque of 30 Ncm. The amount of preload was hypothesized to 650N, and round and flat type prostheses were loaded to 200 N. Four loading offset point (0, 2, 4, 6 mm from the center of the implants) were evaluated. Models were processed by the software programs HyperMesh and ANSA. The PAM-CRASH 2G simulation software was used for analysis of stress. The PAM-VIEW and HyperView were used for post processing. Results. The results from experiment were as follows; 1. von Mises stress value is increased in order of bone, abutment, implant and abutment screw. 2. von Mises stress of abutment screw is lower when platform switching. 3. von Mises stress of implant is lower when platform switching until loading offset 4 mm. 4. von Mises stress of abutment is similar between each other. 5. von Mises stress of bone is slightly higher when platform switching. Conclusion. The von Mises stress pattern of implant components is favor when platform switch ing but slightly higher in bone stress distribution than use of wide abutment. The research about stress distribution is essential for investigation of the cortical bone loss.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.710-713
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• 2005

Many impact or drop test researches of home appliances are published, but those of toys cannot be found easily. External impacts are the primary causes of fracture of toys. For impact proof design, the finished product should pass an impact test after molding design. There are several international toy safety standards or requirements such as US CPSC(Consumer Product Safety Commission), ASTM F963-96a, EN71 and so on. The puppy robot which patrols around the house, namely, the watchdog was selected to investigate toy safety because it has considerable weight and outer panels are made of plastics. First the model of watchdog robot was obtained by 3 dimensional scan. Surface data can be generated from 3D polygon data of the watchdog. A reliable drop simulation method for the watchdog was established using Pam-crash program according to Korean toy safety standards. When there is a low impact allowance value, the molding design should be reinforced or changed. It was found that the maximum impact stress reaches the ultimate stress of panel material.

• 한국정밀공학회지
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• 제17권8호
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• pp.100-105
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• 2000

In this study the structural design concepts of main parameters of a Cathode Ray Tube(CRT) such as frame spring and shadow mask were proposed to guarantee a failure-proof CRT under mechanical shock. With computer simulation and experiments some information on the structural design concept was obtained as followings: the frame and the shadow mask of the CRT needed designing to increase strength so double-beads shape at the corner of frame was newly designed for it, And the spring which interconnected frame with panel glass was required to deform elastically for the purpose of absorbing the shock energy in the direction of drop. A new type of spring 'twisting spring' was designed to achieve the flexibility in that direction. By using it the deformation energy of a shadow mask could reduced to some degree. To accomplish those simulations commerical codes Pam-Crash and I-DEAS were used and a typical CRT was analyzed as an example to prove the usefulness of this study.

• 대한치과보철학회지
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• 제44권3호
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• pp.295-313
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• 2006

Statement of problem. Higher fracture rates were reported for Branemark implants placed in the maxilla and for 3.75 mm diameter implants installed in the posterior region. Purpose. The purpose of this study was to investigate the fracture of a fixture by finite element analysis and to compare different diameter of fixtures according to the level of alveolar bone resorption. Material and Methods. The single implant and prosthesis was modeled in accordance with the geometric designs for the 3i implant systems. Models were processed by the software programs HyperMesh and ANSA. Three-dimensional finite element models were developed for; (1) a regular titanium implant 3.75 mm in diameter and 13 mm in length (2) a regular titanium implant 4.0 mm in diameter and 13 mm in length (3) a wide titanium implant 5.0 mm in diameter and 13 mm in length each with a cementation type abutment and titanium alloy screw. The abutment screws were subjected to a tightening torque of 30 Ncm. The amount of preload was hypothesized as 650 N, and round and flat type prostheses were 12 mm in diameter, 9 mm in height were loaded to 600 N. Four loading offset points (0, 2, 4, and 6 mm from the center of the implants) were evaluated. To evaluate fixture fracture by alveolar bone resorption, we investigated the stress distribution of the fixtures according to different alveola. bone loss levels (0, 1.5, 3.5, and 5.0 mm of alveolar bone loss). Using these 12 models (four degrees of bone loss and three implant diameters), the effects of load-ing offset, the effect of alveolar bone resorption and the size of fixtures were evaluated. The PAM-CRASH 2G simulation software was used for analysis of stress. The PAM-VIEW and HyperView programs were used for post processing. Results. The results from our experiment are as follows: 1. Preload maintains implant-abutment joint stability within a limited offset point against occlusal force. 2. Von Mises stress of the implant, abutment screw, abutment, and bone was decreased with in-creasing of the implant diameter. 3. With severe advancing of alveolar bone resorption, fracture of the 3.75 and the 4.0 mm diameter implant was possible. 4. With increasing of bending stress by loading offset, fracture of the abutment screw was possible.