• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.202-205
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• 2009

Tubular torsion beam of high strength steel is going about in an automotive rear axle due to the advantages of light weight and efficient rear packaging capability. High strength tubular beam can be manufactured by the hydroforming in order to ensure dimensional accuracy, while a conventional stamping has been used for steel tubular beam. Internal pressure, feeding and their combination are the key factors of controlling the process. Based on the numerical simulation and try-outs, the optimized hydroforming process conditions for the high strength tubular beam were suggested.

• Structural Engineering and Mechanics
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• v.10 no.2
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• pp.125-138
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• 2000

The paper analyzes the problem of torsion in an adhesive non-tubular bonded single-lap joint. The joint considered consists of two thin rectangular section beams bonded together along a side surface. Assuming the materials involved to be governed by linear elastic laws, equilibrium and compatibility equations were used to arrive at an integro-differential relation whose solution makes it possible to determine torsional moment section by section in the bonded joint between the two beams. This is then used to determine the predominant stress and strain field at the beam-adhesive interface (stress field along the direction perpendicular to the interface plane, equivalent to the applied torsional moment and the corresponding strain field) and the joint's elastic strain (absolute and relative rotations of the bonded beam cross sections). All the relations presented were obtained in closed form. Results obtained theoretically are compared with those given by a three dimensional finite element numerical model. Theoretical and numerical analysis agree satisfactorily.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.147-150
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• 2005

The torsion beam axle type is widely used in the rear suspension for small passenger car because of low cost, good performance and etc. The FE and dynamic analysis using the computer are very helpful for the efficiency of the torsion beam design. First of all, the reliability on the computational model must be verified for the analysis. In this study, The FE model of the torsion beam was verified according to comparison with he test data. And after making the flexible body using the FE model, the dynamic characteristic of the tubular type torsion beam axles was compared with that of the V-beam type.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.231-232
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• 2008

• Transactions of Materials Processing
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• v.24 no.1
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• pp.13-19
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• 2015

For an accurate analysis of hot stamping, a coupled simulation with different aspects of the process(i.e. mechanical, thermal, and phase transformation) is needed. However, coupled simulations are time consuming and costly. Therefore, the current study proposes a simplified method focused on the forming for the hot stamping simulation of a coupled torsion beam axle (CTBA) tubular beam. In this simplified method, non-isothermal conditions were assumed and only conduction was considered, since it represents the majority of the heat transfer during hot stamping. In addition, temperature and strain rate effects were also included. Moreover, an isothermal simulation was conducted and compared with a non-isothermal simulation. Finally, the simulations were verified by experiments. In conclusion, the proposed method is shown to be effective for the development of tube-type parts, and it effectively predicts the deformation of the tubular beam during hot stamping.

• Transactions of Materials Processing
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• v.16 no.3 s.93
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• pp.201-209
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• 2007

Generally, the forming process of suspension system parts have been considered only considered with the formability and have not been considered with the durability of suspension system. But the durability of suspension system is very important characteristic for the dynamic performance of vehicle. Therefore, the suspension system should be manufactured to consider the durability as well as the formability. This paper is about an optimum forming process design with the effect of section properties to consider the roll durability of torsion beam type suspension. In order to determine the tube hydroforming process for the satisfaction the roll durability, the stamping and hydroforming simulation by finite element method were performed. And the results from finite element analysis and roll durability examination showed the tube hydroforming process of torsion beam is optimized as satisfying the durability performance.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.32-35
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• 2004

The development of automotive rear chassis part using tube forming process has advantage of increase in part durability and decrease in its weight. We developed tubular type rear CTBA(Coupled Torsion Beam Axle) part with 60K high strength steel developed by POSCO in this project. The result was demonstrated that tubular type CTBA shows excellent durability performance and $10\%$ weight reduction compared with V-beam type CTBA in our work. Furthermore, we will adapt this technology to mass production and apply to the other chassis parts.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.339-344
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• 2013

Hot forming using boron steel is currently used for manufacturing low-weight automobile body parts, and a high tensile strength of about 1,500 MPa is obtained after hot forming. However, a high fatigue life is a more important factor than high strength when it is used for automobile suspension parts. A tubular torsion beam axle (TTBA) is one of these suspension parts, and this research deals with the fatigue characteristic of TTBA using hot forming. The low cyclic fatigue life of boron steel is investigated according to the cooling method. In addition, a structural and fatigue analysis of TTBA is performed to predict the fatigue life. The stress concentration that occurs in the tubular torsion beam is found, and the longest fatigue life occurs when rapid cooling is utilized in the TTBA fabrication.