• Earthquakes and Structures
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• v.4 no.1
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• pp.41-62
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• 2013

A comprehensive experimental program of cyclic tests on 1:3-scale models of bridge piers is going to be carried out at the Laboratory of Structures and Materials of the University of Basilicata. The testing models include eight RC single shaft piers with hollow circular cross section. Four piers have been realised using corroded steel rebars. In this paper, the results of preliminary numerical simulation analyses of the cyclic behaviour of the piers, carried out with Opensees using fiber-based models, are presented. Pull-out and lap-splice effects of steel rebars have been taken into account in the numerical analyses. First, the experimental specimens and the test set up are presented. Next, the results of the numerical analyses are discussed. In the numerical analyses, different configurations and levels of corrosion have been considered. The effective stiffness and equivalent damping of the piers is reported as a function of pier ductility and pier drift.

• Journal of the korean Society of Automotive Engineers
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• v.4 no.3
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• pp.48-55
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• 1982

In the present the strain gauge type torque transducers consist of solid shaft as sensor, slip ring, brush and bridge circuit as detecting circuit. So in the case of measuring the low-capacity torque, the error caused by technical mistake in mounting stain gauge on the small sensor and especially by contact resistance between slip ring and brush takes place more than the large sensor. Therefore in this study constant voltage in order to have no effect of contact resistance is supplied to the hollow shaft and Schrobron Bridge Circuit. Through the experiment good results were obtained as follows; linearity, hysterisis and zero drift as static characteristics is within 1% F.S respectively. Also when loading, zero drift is about 2% F.S.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.772-775
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• 2003

A bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is a hollow cylinder, which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the force applied to the shaft and the relative deformation of a bushing is nonlinear and exhibits features of viscoelasticity. A force-displacement relation for bushings is important for multibody dynamics numerical simulations. For the nonlinear viscoelastic axial response, Pipkin-Rogers model, the direct relation of force and displacement, has been derived from Lianis model and the sinusoidal input was used for Pipkin-Rogers model, and the affection of displacement with frequency change was studied with Pipkin-Rogers model.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.474-478
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• 2004

A bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is a hollow cylinder, which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the force applied to the shaft and the relative deformation of a bushing is nonlinear and exhibits features of viscoelasticity. A force-displacement relation for bushings is important for multibody dynamics numerical simulations. For the nonlinear viscoelastic axial response, Pipkin-Rogers model, the direct relation of force and displacement, has been derived from Lianis model and the sinusoidal input was used for Pipkin-Rogers model, and the affection of displacement with frequency change was studied with Pipkin-Rogers model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.6
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• pp.484-491
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• 2016

The purpose of this development is weight reduction of hollow type steel torque bar by changing the material from steel to composite. Structure analysis is executed by the finite element model generated by the structural load condition and geometric structure requirement. According to this analysis result, optimized ply sequence and wall thickness are defined. To simulate analysis result, torsion test for composite torque bar was performed. Throughout the test result, the stiffness and strength requirement of composite torque bar was verified.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.2 s.257
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• pp.152-159
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• 2007

A study on the control of free vibration and stability characteristics of rotating hollow circular shafts subjected to compressive axial forces is presented in this paper. Both passive structural tailoring technique and active control scheme via collocated piezoelectric sensing and actuation are used in the study Gyroscopic and centrifugal forces combined with the compressive axial force contribute to the occurrence of divergence and flutter instabilities of the rotating shaft. The dual methodology based on the passive and active control schemes shows a high degree of efficiency toward postponement of these instabilities and expansion of the domain of stability of the system. The structural model of the shaft is based on an advanced thin-walled beam structure that includes the non-classical effects of transverse shear, anisotropy of constituent materials and rotatory inertia.

• Proceedings of the KAIS Fall Conference
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• 2001.11a
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• pp.117-121
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• 2001

기계설계에서 설계의 객관적인 계산치의 도출을 통한 설계검증이 중요한 부분이다. 여기서 우리는 기계요소 및 시스템 설계용 CAE소프트웨어를 이용하여 설계 검증을 해봄으로서 보다 객관적이고 명확한 설계 개선 안을 쉽게 도출할 수 있다는 것을 제시하고자 한다. 구체적 사례로 발전소 등의 유량을 조정하는 Hollow let Valve 구동축 부분의 안전계수를 검토하여 설계적 개선안을 도출시키고 설계자가 설계하는 단계에서 미리 문제점을 쉽게 발견하고 개선하는 방법을 연구한 결과를 정리한 내용은 다음과 같다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.204-209
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• 2003

An elastomeric bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is an elastomeric hollow cylinder which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the load applied to the shaft or sleeve and the relative deformation of elastomeric bushing is nonlinear and exhibits features of viscoelasticity. A load-displacement relation for elastomeric bushing is important for dynamic numerical simulations. A boundary value problem for the bushing response leads to the load-displacement relation which requires complex calculations. Therefore, by modifying the constitutive equation fur a nonlinear viscoelastic incompressible material developed by Lianis, the data fur the elastomeric bushing material was obtained and this data was used to derive the new load-displacement relation for radial response of the bushing. After the load relaxation function for the bushing is obtained from the step displacement control test, Pipkin-Rogers model was developed, Solutions were allowed fur comparison between the results of Modified Lianis model and those of the proposed model. It is shown that the proposed Pipkin-Rogers model is in very good agreement with Modified Lianis model.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.415-419
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• 2003

An elastomeric bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is an elastomeric hollow cylinder which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the load applied to the shaft or sleeve and the relative deformation of elastomeric bushing is nonlinear and exhibits features of viscoelasticity. A load-displacement relation for elastomeric bushing is important for dynamic numerical simulations. A boundary value problem for the bushing response leads to the load-displacement relation which requires complex calculations. Therefore, by modifying the constitutive equation for a nonlinear viscoelastic incompressible material developed by Lianis, the data for the elastomeric bushing material was obtained and this data was used to derive the new load-displacement for radial response of the bushing. After the load relaxation function for the bushing is obtained from the step displacement control test, Pipkin-Rogers model was developed. Solutions were allowed for comparison between the results of Modified Lianis model and those of the proposed model. It is shown that the proposed Pipkin-Rogers model is in very good agreement with Modified Lianis model.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2002.05a
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• pp.129-134
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• 2002

This study is focused on the layout design with sizing for the main propulsion shafting with controllable pitch propeller system. For appropriate design and successful manufacturing of controllable pitch Propeller system, it is based on specifications to be required from the customer as well as the stresses calculation and analysis of main propulsion system for hollow shafting. And it must be performed according to the U.S military specifications MIL-STD-2189(SH) with drawing of NAVSHIPS 803-2145807, and also the stress analysis by applying safety factor. The results are as follows : 1. For the main propulsion system with controllable pitch propeller, it is designed the following items propeller diameter, hub diameter, dimensions of oil distribution or actuating unit based on shaft mounting type, diameters of propeller and intermediate shaft, dimension of split muff coupling, coupling flange thickness and of coupling bolt diameter. 2. As the results, we can get complete our own design ability for the main propulsion shafting with controllable pitch propeller system with critical data which are necessary to establish shafting arrangement from the ship building companies.