• Computational Structural Engineering
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• v.6 no.4
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• pp.99-105
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• 1993

In this paper a useful method on evaluating the joint stiffness of a bolted member was introduced using optimization technique on the basis of Finite Element Method. A finite element model having one directional gap element at boundary area was introduced to compensate the prying force in jointed members which might be caused by geometrical configuration of members. Results showed a good agreement with classical method in certain range and will be available to define the appropriate design margin of pre-load design.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.94-97
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• 2005

The strength of aluminum 7075 and carbon composite hybrid joints was studied for adhesive, bolt, and the adhesive-bolt combined joints. Several hybrid joint specimens were tested to get the failure load and modes for three types of the joints. Adhesive Cytec EA9394S was used for aluminum and carbon bonding. Failure load of the adhesive-bolt combined joint was 94 % of the sum of the failure load of the separately bonded and bolted joints. Hybrid joint also showed more stable failure behavior than the simple adhesive or bolted joint.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.2
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• pp.73-79
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• 1999

Most of mechanical structures are combined of substructures such as beams and/or plates. There are few systems with unibody structures but are many systems with united body structures. Generally the dynamic a nalysis of whole structures is performed under alternation load. In the structure design, the analysis of each bolted joint is more important than others for zero severity. This paper presents the analysis method of contact stress distribution factor in the bolted joint with variable fastening torque on joints in the structure. At first, a static vibration test was performed to find out a nominal stress of bolt jointed plates from the relationship between natural frequency and nominal stress. Then a contact stress was computed at contact point between bolt and plate in the structure. It is believed that the proposed method has promisiong implications for safer design with index of contact stress distribution factor and has merits for cost-down and saving time at the beginning of vehicle development.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.7
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• pp.287-294
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• 2001

The identification of connection stiffnesses of bolted structures is presented using FRT-based substructural sensitivity analysis. The substructural design sensitivity formula is derived and plugged into the optimization module of MATLAB to identify connection stiffnesses of an air-conditioner compressor or passenger Car. The air-conditioner composed of a compressor and a bracket, is analysed by using the FRT-based substructural(FBS) method to obtain FTRs an FE model is generated for the bracket, and the impact hammer test is performed for the compressor, Obtained FRTs are combined to calculate the reaction force at the connection point and the system response. By minimizing the difference between a target FRT and calculated one the connection element properties of the air-conditioner syste are identified It is shown that the proposed identification method is effective for a real problem.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.413-418
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• 1998

In this paper, a dynamic modeling approach is introduced to identify the dynamic characteristics of the structural/mechanical joints within an one-dimensional structure. A structural joint is represented by the four-pole parameters and the four-pole parameters are determined from the measured frequency response functions by using the spectral element method. As the illustrative examples, a cantilevered beam and a clamped-clamped beam, each consists of two beams connected by a bolted joint, are investigated to evaluate the present modeling approach. It is found that the dynamic responses predicted by using the identified four-pole parameters for the bolted joint are well agreed with the dynamic responses measured up to high frequency.

• Wind and Structures
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• v.31 no.1
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• pp.1-14
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• 2020

This paper presents a method of estimation of fatigue demands on connection bolts of tubular steel wind turbine towers. The presented method relies on numerical simulation of aerodynamic loads and structural behavior of bolted connections modeled using finite element method. Variability of wind parameters is represented by a set of values derived from their probability densities, which are adjusted based on field measurements. Numerically generated stress time-series show agreement with the measurements from strain gauges inside bolts, in terms of power spectra and the resulting damage. Position of each bolt has a determining effect on its fatigue damage. The proposed framework for fatigue life estimation represents the complexities in loading and local behavior of the structure. On the other hand, the developed procedure is computationally efficient since it requires a limited number of simulations for statistically representing the wind variations.

• Journal of Power System Engineering
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• v.5 no.4
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• pp.38-43
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• 2001

This paper describes the effect of dynamic characteristics in tube line by external vibration conveying fluid with the power steering system. By the experimental analysis we found out that the factor of system vibration is the fluid-structure interaction of tube line. In fluid-filled tube system we study on the influence that the natural frequency of system and the frequency of wave motion produce upon through experiment. Experiments are modal test, frequency response function in continuous system, and vibrating tests when the system is driving with bolted clamping joint condition. From the results of the experimental studies, we obtained that the natural frequencies of system are very important than the wave induced vibrations. And we found that the tendency of system vibration level was decreased by bolting force, bolting condition and clamping distance.

• Journal of Korean Society of Steel Construction
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• v.8 no.3 s.28
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• pp.151-160
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• 1996

The fatigue test under the constant amplitude repeated loading is performed to investigate the fatigue behavior of the Torque Shear type high tension bolted joint which is able to manage the axial force uniformly. From the test results, it's known that the reduction of the axial force of T/S bolt followed by the elasped time is similar to that of the high tension bolts. The difference of relaxation is not occurred according to the position of bolts, the size of the introduced axial force but the effect of the variation of temperature is large. In the reduction of the axial force followed by the cumulation of the fatigue load, the outer bolt is larger than the inner bolt. This result depends on the difference in the distribution of the non-slip zone. The variation of the surface roughness affects the slip and the reduction of the anal force.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.323-330
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• 2001

The existing bonding methods of steel pipe piles into pile caps have many problems during construction or design. To overcome these, the composite bonding method of the bolting type and the welding type are proposed in this stud\ulcorner. The full scale test and the numerical analysis using finite element method were performed to verify the function of them. As results, the method of the filled with concrete in steel pipe piles head was good effective to increse strength. And the composite bonding methods are effective to protect the damage caused by earthquake than the bolted bonding method. Also, the composite bonding methods are cheaper than the existing bonding methods and a good construction as well.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.3
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• pp.183-190
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• 2006

Generally, application of steel pile as deep foundation member needs specials requirement for the connection method between steel pipe and concrete footing. To investigate real compressive behavior of connection member between steel pipe pile and concrete footing, three specimens were tested with carefully designed experimental system. Main test variable is the connection method between steel pipe pile and concrete footing. The bolted bonding method and hook bonding method was considered as the connection method in this study. From the test results gained from experiment, it was conformed that two types of connection method have the almost same compressive resistance capacity. Therefore, we can conclude that these two connection methods can be used as the strengthening method to verify the compressive composite action of concrete and steel pipe pile.