• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.168-173
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• 2002

The durability test, along with the crashworthiness test, requires the most time and expense in the vehicle development process. The durability design using CAE tools reduces the time required for both the durability test and actual vehicle production. Existing dynamic stress analyses designed fir the analysis of vehicle fatigue mainly calculate the dynamic stress history and fatigue after performing dynamic analysis and stress analysis with relevant software applications and then superpositioning the dynamic load history and stress influence coefficient at each joint. This approach is a complex process, taking into account the flexibility of the parts. It is, however, incapable of giving accurate consideration to the contacts between components, the non-linearity of materials, and tire-road surface interactions. This approach also requires that the analysts have an expertise in software applications of various kinds or an expert in each area must perform the analysis. This requires as a great deal of manpower and time. In order to complement the existing approaches for dynamic stress analysis, this study aims at the following: (1) to suggest the simple and accurate analysis technique which is capable of producing all the possible necessary results; (2) to reduce dramatically the time and manpower needed to construct a model designed to analyze dynamics, quasi-static stress, and fatigue; and (3) to enable an accurate analysis of fatigue by improving the accuracy of dynamic stress. we verify the presented analysis method through durability evaluation of the knuckle of passenger car.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.9 s.252
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• pp.1041-1048
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• 2006

The pulley is one of core mechanical elements in the power steering system for vehicles. The pulley operates under both the compressive loading and the torque. Therefore, to assure the safety of the power steering system, it is very important to investigate the durability and the optimization of the pulley. In this study, the applied stress distribution of the pulley under high tension and torsion loads was obtained by using finite element analysis. Based on these results the fatigue life of the pulley with the variation of the fatigue strength was evaluated by a durability analysis simulator. The results at 50% and 1% for the failure probability were compared with respect to the fatigue life. In addition to the optimum design for the fatigue life is obtained by the response surface method. The response function utilizes the function of the life and weight factors. Within range for design life condition the minimization of the weight, one of the formulation, is obtained by the optimal design. Moreover the optimum design by considering its durability and validity is verified by the durability test.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.2
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• pp.199-205
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• 2013

Stress and deformation on forklift happened at loading, unloading or moving freight are studied by structural and fatigue analysis in this study. As model 1 as closing type between forks has lower stress and stain than model 2 at opening type, model 1 has more durability than model 2. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'SAE bracket history' with the severest change of load at model 1 and 2, maximum life is shown with Cycle. Minimum damage with 854 at model 2 becomes much higher than model 1. As the gap between forks becomes open, the damage probability becomes higher. The structural result of this study can be effectively utilized with the safe and stable design of forklift by investigating prevention and durability against its damage.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.2
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• pp.8-13
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• 2013

This study analyzes about poclain bucket through fatigue durability analysis. Maximum equivalent stress and total deformation are shown at the lower of bucket and edge part respectively. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of -10000Pa to 5000MPa and the amplitude stress of 0 to 6000MPa, the possibility of maximum damage becomes 3%. This stress state can be shown with 5 or 6 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of poclain bucket by investigating prevention and durability against fatigue damage.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.144-150
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• 2003

Recently, the virtual test techniques using computer simulation play an important part in the vehicle development procedures in order to reduce the development time and cost by replacing the physical prototypes of the vehicle components or systems with the virtual prototypes. In this paper, virtual durability test procedures for the vehicle suspension module have been developed. Virtual durability test consists of dynamic simulation computing load history of suspension components, fatigue analysis computing the life of components. A vehicle suspension module for dynamic simulation are developed and validated by comparison with the measured data obtained from the field vehicle test. And on the basis of the validated vehicle suspension model, fatigue analysis has been performed for the virtual durability design of the suspension components.

• Journal of the Korean Society for Railway
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• v.8 no.5
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• pp.425-433
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• 2005

For the design of welded bogie frame, the concept of multidisciplinary engineering activities, i.e. static, fatigue and dynamic analysis, has been applied, in which the sharing of design parameters related with each analysis and the collaboration of the working parts in charge should be fulfilled. However, in spite of these necessities, the multi-disciplinary engineering activities couldn't be performed in practice due to tack of the automation of the required analysis. In this paper, an automation of fatigue durability analysis of welded bogie frame according to UIC-Code was proposed by using the Model Center, which enables to integrate the several tools for the fatigue durability analysis, i.e. I-DEAS, ANSYS and BFAP, and to perform iterative analysis works in relation to the geometrical change of transom support bracket. Besides, the wrapping programs to control I/O-data and interfaces of these tools were developed. The developed automation technique brings not only significant decreasing man-hour required in the durability analysis, but also providing a platform of the multidisciplinary engineering activities.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.1-8
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• 2013

This study investigates life and damage due to structural and fatigue load at speaker placer with wall hanger type. As the small stress and deformation are shown at the models of A, B and C shapes on structural analysis, there is no problem at installing speaker placer. As the largest stress is happened at the middle part of joint on the models of A, B and C shapes, this part must be considered at the design. A shape is thought to have most fatigue damage among 3 shape models. C shape model has most excellent, but A model has least at fatigue durability. This study result is applied with the design of speaker placer and it can be useful at predicting prevention and durability against its damage.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.394-399
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• 2004

In order to secure the safety of power steering system, it is necessary to perform the strength and the fatigue analysis of pulley in this paper. The applied stress distribution of the pulley subject to combined loads condition was obtained using finite element analysis. Based on these results, the fatigue life of the pulley with the variation of the fatigue strength was evaluated using durability analysis simulator. The optimal hole size to improved the safety of the pulley was investigated using parametric study. Moreover, the predicted fatigue life cycle with the simulator was verified by experimental tests.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.36-44
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• 2013

This study investigates life, damage and durability through the analyses of fatigue load and vibration on disk brake models of A, B and C. Maximum equivalent stress is happened at the inside of disk brake on these models. As there are A, B and C models by order of life, model A has the most stable strength on fatigue analysis, The deformations at 3 kinds of models become nearly same on natural frequency analysis. The maximum total deformation and equivalent stress is shown at 1617Hz by harmonic vibration analysis on these models. As there are A, B and C models by order of deformation and stress, model A becomes lowest and safest. This study result can be effectively utilized with the design of brake disk in order to improve durability and prevention against its fatigue damage and vibration.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.154-161
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• 1995

There are several kinds of driving conditions according to the characteristic of each vehicle diver. Automaker produces vehicle strong enough to satisfy this several driving conditions at the point of vehicle durability. In order to develop the car in a short period, Automaker engineer tests vehicle at serveral accelerated durability test roads. Before testing the vehicle durability, test engineer must know how much this test road severe than general field road which is composed of high way, city road, paved road and unpaved road. This paper suggests two types of road severity test method that is using relative fatigue life prediction method and using absolute fatigue life prediction method, and also present the merits and demerits of two test methods.