• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.985-988
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• 2002

The Spindle-]fearing System is very important unit for geometrical accuracy in machine tools. To improve effectively the weak point of spindle system, it is necessary that the contribution ratio of spindle core parts to static and dynamic stiffness is clarified. In this paper, static contribution ratio of core parts is calculated by overlapping static deformation of basic spindle design with one flexible parts. The dynamic contribution ratio for natural frequency and dynamic deformation at spindle end is obtained by calculating correlation between original and basic spindle deformation, by curve fitting with regressive method. It is proved the validity of estimation result is correct.

• 대한기계학회논문집A
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• 제24권8호
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• pp.1949-1957
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• 2000

All the loads in the real world act dynamically on structures. Since dynamic loads are extremely difficult to handle in analysis and design, static loads are utilized with dynamic factors. The dyna mic factors are generally determined based on experiences. Therefore, the static loads can cause problems in precise analysis and design. An analytical method based on modal analysis has been proposed for the transformation of dynamic loads into equivalent static load sets. Equivalent static load sets are calculated to generate an identical displacement field in a structure with that from dynamic loads at a certain time. The process is derived and evaluated mathematically. The method is verified through numerical tests. Various characteristics are identified to match the dynamic and the static behaviors. For example, the opposite direction of a dynamic load should be considered due to the vibration response. A dynamic bad is transformed to multiple equivalent static loads according to the number of the critical times. The places of the equivalent static load can be different from those of the dynamic load. An optimization method is defined to use the equivalent static loads. The developed optimization process has the same effect as the dynamic optimization which uses the dynamic loads directly. Standard examples are solved and the results are discussed

• Structural Engineering and Mechanics
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• 제41권2호
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• pp.243-262
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• 2012

Nonlinear static analysis as an essential part of performance based design is now widely used especially at design offices because of its simplicity and ability to predict seismic demands on inelastic response of buildings. Since the accuracy of nonlinear static procedures (NSP) to predict seismic demands of buildings affects directly on the entire performance based design procedure, therefore lots of research has been performed on the area of evaluation of these procedures. In this paper, one of the popular NSP, FEMA356, is evaluated and compared with modal pushover analysis. The ability of these procedures to simulate seismic demands in a set of reinforced concrete (RC) buildings is explored with two level of base acceleration through a comparison with benchmark results determined from a set of nonlinear time history analyses. According to the results of this study, the modal pushover analysis procedure estimates seismic demands of buildings like inter story drifts and hinges plastic rotations more accurate than FEMA356 procedure.

• 제어로봇시스템학회논문지
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• 제10권7호
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• pp.590-596
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• 2004

A passivity-based dynamic output feedback controller design is considered for a finite collection of non-square linear systems. Design of a single controller for a set of plants i.e. simultaneous stabilization is an important issue in the area of robust control design. We first determine a squaring gain matrix and an additional dynamics that is connected to the systems in a feedforward way, then a static passivating control law is designed. Consequently, the actual feedback controller will be the static control law combined with the feedforward dynamics. A necessary and sufficient condition for the existence of the parallel feedforward compensator is given by the static output feedback formulation. In contrast to the previous result [1], a technical condition for constructing the parallel feedforward compensator is removed by proposing a new type of the parallel compensator.

• International Journal of Aeronautical and Space Sciences
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• 제16권2호
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• pp.137-147
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• 2015

Hypersonic vehicles exhibit distinct dynamic and static characteristics, such as unstable dynamics, strict altitude angle limitation, large control bandwidth, and unconventional system sensitivity. In this study, compromise relations between the dynamic features and static performances for hypersonic vehicles are investigated. A compromise optimal design for hypersonic vehicles is discussed. A parametric model for analyzing the dynamic and static characteristics is established, and then the optimal performance indices are provided according to the different design goals. A compromise optimization method to balance the dynamic and static characteristics is also discussed. The feasibility of this method for hypersonic vehicles is demonstrated.

• 산업공학
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• 제25권4호
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• pp.416-421
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• 2012

One of the activities to improve software quality in ISO 26262 is to apply the design principles for software unit design and implementation mentioned in ISO 26262-6, including the evaluation activity. Before evaluation activity, the tool is compared and selected for evaluation. Because the results of the tool a company selected might have an effect on product quality. In this paper, we suggest the method to compare industrial static analysis tools with some of "MISRA C : 2004 Exemplar Suite" and all lessons learned from comparing tools are described. The result on comparison shows that we just couldn't rely on a result of Static Analysis Tool and need to have another appropriate processes and guidelines to evaluate a software.

• 한국화재소방학회논문지
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• 제31권4호
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• pp.86-94
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• 2017

본 연구에서는 소방시설의 내진설계기준에 의한 Cook Book 방식과 Static System Analysis 방식을 비교 해석하였다. Cook Book 방식은 배관을 동일 구간마다 나누어 해석한다. 이 방식은 배관, 물 그리고 관부속의 무게에 따라 버팀대를 설계하는 방식으로 해석하는 구간 외에는 응력해석이 불가능하다. 그러나 Static System Analysis는 배관 전체를 하나의 구조체로 보기 때문에 전체 배관에 대한 응력해석이 가능하다. 국소적으로 발생되는 치명적 응력 값에 대해서는 국부적으로 배관의 응력을 해소할 수 있는 장치의 설치를 통해 적극적으로 배관해석을 할 필요가 있다. 국내의 경우 소방시설의 내진설계기준이 Cook Book 방식만을 제시하고 있어 내진설계의 다양화에 많은 문제점을 가지고 있다. 그러므로 공학적으로 검증된 여러 종류의 Static System Analysis 방법을 통해 배관의 내진 설계를 방법을 적용할 필요가 있다.

• 한국항공우주학회지
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• 제45권7호
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• pp.574-580
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• 2017

항공기에는 비행 중 공기 중으로부터 축적된 정전기를 방출시키기 위하여 정전기방출기를 장착하여야 한다. 특히 정전기 방출기에 의해 방출되지 않으면, 항공기 표면에 이온화현상이 발생하게 되고, 그에 따라 항공기 외부로 돌출된 안테나 및 날개 끝부분에서 코로나 현상을 발생시켜 무선통신 및 장비운용에 영향을 미치게 한다. 본 논문에서는 항공기 정전기 방출기를 장착하기 위하여 항공기 표면적과 속도 그리고 기후조건을 분석하였다. 또한 그 분석결과를 바탕으로 정전기 방출기 장착설계를 수행할 수 있으며, 장착된 정전기 방출기의 기능시험을 통하여 효과적으로 장착설계가 되어있음을 확인할 수 있다. 그리하여 본 연구결과를 바탕으로 추후 다양한 크기와 임무조건을 가지는 항공기의 정전기 방출기 장착설계를 최적화하여 수행할 수 있다.

• 한국CDE학회논문집
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• 제16권3호
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• pp.178-186
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• 2011

Static CAD models are the CAD models that do not have feature information and modeling history. These static models are generated by translating CAD models in a specific CAD system into neutral formats such as STEP and IGES. When a CAD model is translated into a neutral format, its precious feature information such as feature parameters and modeling history is lost. Once the feature information is lost, the advantage of feature based modeling is not valid any longer, and modification for the model is purely dependent on geometric and topological manipulations. However, the capabilities of the existing methods to modify static CAD models are limited, Direct modification methods such as tweaking can only handle the modifications that do not involve topological changes. There was also an approach to modify static CAD model by using volume decomposition. However, this approach was also limited to modifications of protrusion features. To address this problem, we extend the volume decomposition approach to handle not only protrusion features but also depression features in a static CAD model. This method first generates the model that contains the volume of depression feature using the bounding box of a static CAD model. The difference between the model and the bounding box is selectively decomposed into so called the feature volume and the base volume. A modification of depression feature is achieved by manipulating the feature volume of the static CAD model.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.613-616
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• 1997

MDO(Multidisciplinary Design Optimization) methodology is an emerging new technology to solve a complicate structural analysis and design problem with a number of design variables and constraints. In this paper MDO methodology is adopted through the use of computer aided engineering(CAE) system. And this paper treats the structural design problem of RIROB(Reactor Inspection Robot) through the application of MDO methodology. In a MDO methodology application to the structural design of RIBOS, kinetodynamic analysis is done using a simple fluiddynamic analysis model for the warter flow over the sensor support surface instead of difficult fluid dynamic analysis. Simultaneously the structural static analysis is done to obtain the optimum structural condition. The minimum thickness (0.8cm) of the RIROB housing is obtained for the safe design of RIROB. The kinetodynamic analysis of RIROB. The kinetodynamic analysis of RIROB is done using ADAMS and the static structural analysis of RIROB is done using NISA.