• 소음진동
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• 제9권4호
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• pp.795-805
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• 1999

Rubber mounts so called grommets and pipes are two major paths of vibration transmission from a compressor, an important vibration source in an air conditioner, to the whole unit. A procedure of configuring the suction and discharge pipes of the compressor was developed in this paper so as to reduce the vibration transmission through the pipes as well as the grommets. Through investigating the effects of shapes and connecting disrections of pipe elements on vibration transmission, a guideline to configure the pipe layout, which enables to reduce vibration transmission, was proposed. The initial pipe layout by the guideline was optimized with the objective function, minimization of boty vibration transmission and the cost, and with the constraints to yield the final dimensions of the pipes. The procedure not only minimizes the transmitted force to the circumferential devices but enables to eliminate rubber blocks or dampers, which are generally used to avoid resonances of the pipe system.

• 소음진동
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• 제7권6호
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• pp.993-1000
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• 1997

This paper presents a new technique of mathematical treatment using a finite element model for analyzing the vibration of the towed line array. Since the towed line array has the axisymmetricity, axisymmetric elements are used in finite element modeling for the towed array structure. The fluid-structure interaction is also considered. The array consists of a series of identical substructures which can include internal structures such as spacers, hydrophones and ropes. That periodicity of substrucutres permits the substructure synthesis technique using characteristic wave guide for analyzing the response of towed array system. This synthesis technique can reduce the cost of computing the array response. It is suggested that a response of towed array can be computed by the finite element method and substructure synthesis technique using wave guide. Several experiments for towed array were performed to verify the present computation technique. The predicted vibration for the towed array shows good agreement with the measured result.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.343-347
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• 2008

Design of shape for visco-elastic vibration isolation elements, which are very cost-effective and so popular in many applications is frequently based on experiences, intuitions, or trial and errors. Such traditions in shape design make it difficult for drastic changes or new concepts to come out. In this paper, both topological method and shape optimization method are combined together to find out a most desirable isolator shape efficiently by using two commercial engineering programs. ABAQUS and MATLAB. The procedure is divided into two steps. At the first step, a topology optimization method is employed to find an initial shape. where density of either 0 or 1 for finite elements is used for physical realizability. At the second step, based on the initial shape, finer tuning of the shape is done by boundary movement method. An illustration of the procedure will be presented for a mount of an air-conditioner compressor system and the effectiveness will be discussed.

• 한국소음진동공학회논문집
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• 제18권12호
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• pp.1250-1255
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• 2008

Design of shape fur visco-elastic vibration isolation elements, which are very cost-effective and so popular in many applications is fi?equently based on experiences, intuitions, or trial and errors. Such traditions in shape design make it difficult for drastic changes or new concepts to come out. In this paper, both topological method and shape optimization method are combined together to find out a most desirable isolator shape efficiently by using two commercial engineering programs, ABAQUS and MATLAB. The procedure is divided into two steps. At the first step, a topology optimization method is employed to find an initial shape, where density of either 0 or 1 for finite elements is used fur physical realizability. At the second step, based on the initial shape, finer tuning of the shape is done by boundary movement method. An illustration of the procedure is presented fur a mount of an air-conditioner compressor system and the effectiveness is discussed.

• 환경영향평가
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• 제22권4호
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• pp.381-387
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• 2013

In order to improve the environmental vibration, it is necessary to method for not only reduce the vibration source, but also control the vibration path. In this study, we used borebole for estimate the vibration reduction. And also, we analyzed displacement and vibration velocity caused by the position of borehole as well as the condition of borehole in ground structure. Visual FEA(Finite Element Analysis) program was used in this numerical analysis. The results are as follows : The displacement magnitude and X, Y direction displacement were represented to different results due to the condition and position of borehole, and were represented to the lowest values when the position of borehole is the most close condition from the vibration source. And also, the vibration velocity was decreased as using borebole in ground structure. The isolation efficiency of the vibration was calculated to maximum 18.40% when borehole was established to the most close position from the vibration source and the receive point.

• 전산구조공학
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• 제7권4호
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• pp.127-136
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• 1994

2차원과 3차원모델에 대해 진동전파구간에 설치된 방진구의 진동차단효과가 주파수영역의 경계요소법에 의해 반무한영역지반과 충진지반에서 검토되었다. 연구결과는, 방진구의 효율이 진동원과 관련된 방진구의 위치 및 깊이에 큰 영향을 받으며, 그들의 최적크기는 진동주파수에 대해 민감한 것을 나타낸다.

• 터널과지하공간
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• 제11권4호
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• pp.362-367
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• 2001

지반에서 겨울에 발생할 수 있는 단단한 상부층은 방진벽의 진동차단성능을 변화시킬 수 있다. 본 논문은 상부에 단단한 층이 존재하는 층진 지반(layered soil)에서 표면파의 진동전파와 강성 방진벽의 진동차단 성능에 관한 것이다. 연구는 이차원문제로, 경계요소법을 이용한 수치해석적 방법에 의해 수행되었으며, 진동원은 수직방향으로 조화가 진을 받는 줄기초이다. 검토된 지반은 세 가지로, 균질의 반무한 지반과, 단단한 상부층의 두께를 달리하는 두 개의 지반이다. 단단한 상부층을 갖는 지반에서는 굴절의 지반과 비교하여 아주 커다란 진폭의 감소가 나타났으며, 진동전파 속도의 경우, 물성치에 의해 계산으로 구해지는 진동전파 속도만큼의 크기가 나타나지 않았다. 더욱이 동결지반에서의 진폭은 비동결지반에서 보다 거리에 따라 아주 작은 값이 구해졌다.

• 한국기계가공학회지
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• 제18권4호
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• pp.34-40
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• 2019

We performed shape optimization of an anti-vibration rubber assembly which is used in the field option cabin of agricultural tractors to improve the vibration isolation capability. To characterize the hyper-elastic material property of rubber, we performed uniaxial and biaxial tension tests and used the data to calibrate the material model applied in the finite element analyses. We conducted a field test to characterize the input excitation from the tractor and the output response at the cabin frame. To account for the nonlinear behavior of rubber, we performed static analyses to derive the load-displacement curve of the anti-vibration rubber assembly. The stiffness of the rubber assembly could be calculated from this curve and was input to the harmonic analyses of the cabin. We compared the results with the test data for verification. We utilized Taguchi's parameter design method to determine the optimal shape of the anti-vibration rubber assembly and found two distinct shapes with reduced stiffness. Results show that the vibration at the cabin frame was reduced by approximately 35% or 47.6% compared with the initial design using the two optimized models.

• 한국소음진동공학회논문집
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• 제21권5호
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• pp.475-483
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• 2011

A hybrid electromagnetic actuator with an air mount is designed so as to achieve the desired isolation reduce the vibration efficiency on the floor vibration. The performance specification of the hybrid electromagnetic actuator is determined based on the vibration criterion for vibration-sensitive equipment. In the design stage of the electromagnetic actuator, the simple reluctance method is adapted to analyze magnetic circuits. The result is verified by finite element analysis using ANSYS Emag. Finally, in order to confirm the design performance, a dynamic characteristic test is carried out for the prototype of a hybrid electromagnetic actuator.

• 정보저장시스템학회논문집
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• 제7권2호
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• pp.47-52
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• 2011

This paper presents a method to improve vibration characteristics of servo track write (STW) fixture. STW fixtures supported by flexible mounts are subject to various vibration sources. Using Finite element analysis (FEA) vibration modes of the fixture are identified. The FEA results suggest certain vibration modes be reduced through design change of flexible mounts to improve vibration responses of the fixture. Based on layered flexible mounts theory a parametric study on shear and bending stiffness is performed to obtain a suitable flexible mount design leading to increased resistance to rocking motion. Experiments confirm improvement of vibration characteristics and drive performance through new mounts design.