• Transactions of the Korean Society of Automotive Engineers
• /
• v.7 no.5
• /
• pp.141-153
• /
• 1999

A finite element procedure for the analysis of rubber-like hyperelastic material is developed. The volumetric incompressiblity conditions of the rubber deformation is included in the formulation by using penalty method. In this paper, the behavior of the rubber deformation is represented by hyperelastic constitutive relations based on a generalized Mooney-Rivlin model. The principle of virtual work is used to derive nonlinear finite element equation for the large displacement problem and presented in total-Lagrangian description. The finite element procedure using analytic differentiation resulted in very close solution to the result of the well known commercial packages NISAII AND ABAQUS. Numerical tests show that the results from the numerical differentiation method coincide very well with those from the analytic method and the well known commercial packages in static analysis. The convergency of rubber usingν iteration method is also discussed.

• Journal of Biosystems Engineering
• /
• v.26 no.1
• /
• pp.57-66
• /
• 2001

This study was performed to determine adsorption equilibrium moisture contents of rough rice, brown rice, white rice and rice hull grown in Korea. EMC values were measured by static method using saturated salt solutions at three temperature levels of 20$\^{C}$, 30$\^{C}$ and 40$\^{C}$, and eight relative humidity levels in the range from 11.2% to 85.0%. The measured EMC values were fitted to modified Henderson, Chung-Pfost, and modified Oswin models by using nonlinear regression analysis. The results of comparing root mean square errors for three models showed that modified Henderson and Chung-Pfost models could serve as good models, and that modified Oswin model could not be applicable to rough rice, brown rice, white rice and rice hull.

• International Journal of Automotive Technology
• /
• v.7 no.6
• /
• pp.703-714
• /
• 2006

The growing concern surrounding rollover incidences and consequences of Sports Utility Vehicles(SUV) have prompted to investigate the sensitivity of critical vehicle parameters on rollover. In this paper, dynamic rollover simulation of Sports Utility Vehicles is carried out using a validated nonlinear vehicle model in Matlab/Simulink. A standard model is considered and critical vehicle parameters like CG height, track width and wheel base are varied within chosen specified limits to study its influence on roll behavior during a Fishhook steering maneuver. A roll stability criterion based on Two Wheel Lift Off(TWLO) phenomenon is adopted for rollover propensity prediction. Further dynamic rollover characteristics of the vehicle are correlated with Static Stability Factor(SSF), Roll Stability Factor(RSF) and Two Wheel Lift Off Velocity(TWLV). These findings will be of immense help to SUV chassis designers to determine safety limits of critical vehicle parameters and minimize rollover incidences.

• Proceedings of the KIEE Conference
• /
• 2001.07a
• /
• pp.149-151
• /
• 2001

This paper proposes the design of STATCOM(static synchronous compensator) stabilizer for improving power system stability using fuzzy logic controller(FLC). The STATCOM DC voltage regulator contributes negative damping to the power system as the installation of STATCOM DC voltage regulator. STATCOM stabiliser is superimposed on the AC voltage regulator to compensate the negative damping effect. To evaluate usefulness of the proposed method, we perform the nonlinear simulation on a single-machine infinite bus system. As results of the simulations, the proposed method shows better control performance than PI controller in terms of damping effects.

• Proceedings of the KIEE Conference
• /
• 1998.07b
• /
• pp.461-464
• /
• 1998

Lateral Information Propagation Neural Networks (LIPN) is proposed for on-line interpolation. The proposed neural network technique is the real time computation method through the inter-node diffusion. In the network, a node corresponds to a state in the quantized input space. Each node is composed of a processing unit and fixed weights from its neighbor nodes as well as its input terminal. Information propagates among neighbor nodes laterally and inter-node interpolation is achieved. Through several simulation experiments, real time reconstruction of the nonlinear image information is processed. 1-D LIPN hardware has been implemented with general purpose analog ICs to test the interpolation capability of the proposed neural networks. Experiments with static and dynamic signals have been done upon the LIPN hardware.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05b
• /
• pp.90-95
• /
• 2003

For the safety driving of an automobile which is become individual requisites, a new Neural Network algorithm which recognized the load vehicles in real time is proposed. The proposed neural network technique is the real time computation method through the inter-node diffusion. In the network, a node corresponds to a state in the quantized input space. Each node is composed of a processing unit and fixed weights from its neighbor nodes as well as its input terminal. The most reliable algorithm derived for real time recognition of vehicles, is a dynamic programming based algorithm based on sequence matching techniques that would process the data as it arrives and could therefore provide continuously updated neighbor information estimates. Through several simulation experiments, real time reconstruction of the nonlinear image information is processed. 1-D LIPN hardware has been composed and various experiments with static and dynamic signals have been implemented.

• Earthquakes and Structures
• /
• v.8 no.6
• /
• pp.1387-1406
• /
• 2015

Masonry bridges are the vital components of transportation systems. Although these bridges were constructed centuries ago, they have served a purpose from ancient times to the present day. However, the bridges have needed local renovation and therefore have been rebuilt over different periods in many places. This study focuses on Low Bridge, which is an example of renovated masonry bridges in Turkey. It essentially assesses the structural behavior of the masonry bridge and investigates the integrity of the renovated components. For this purpose, the mechanical properties of the bridge material have been primarily evaluated with experimental tests. Then the static, modal and nonlinear time history analyses have been carried out with the use of finite element methods in order to investigate the structural behavior of the current form of the bridge.

• Journal of the Society of Naval Architects of Korea
• /
• v.32 no.2
• /
• pp.56-67
• /
• 1995

In this paper, a ship-cable-vehicle system's static configuration is shown obtained by solving cable nonlinear statics. Eigenfrequencies of the cable were calculated by the frequency domain analysis application of the linearized cable dynamic equations. Also extreme tensions in a slack-and-snapping long vertical cable were calculated by the clip-ping-off model.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2002.10a
• /
• pp.533-540
• /
• 2002

Tubular joints having a large diameter are reinforced using internal ring stiffener in order to increase the load carrying capacity. In this study, the static strengths of Internally ring-stiffened tubular T-joints subjected to compressive brace loading are assessed. Nonlinear finite element analyses are used to compute the behavior of unstiffened and ring-stiffened T-joints. From the numerical results, Internal ring stiffener is found to efficient in improving the ultimate capacity, and reinforcement effect are calculated. The influence of geometric parameters for members and ring is evaluated. Based on the FE results, regression analysis is performed considering practical sizes of ring stiffener, finally strength estimation formulae for ring-stiffened T-joints are proposed.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.174-177
• /
• 2011

비선형 정적 해석법(NSPs)은 최근 구조물의 지진해석방법으로서 그 사용성을 인정받고 있다. 비선형 정적 해석법은 직관적으로 구조물의 지진해석을 수행할 수 있는 등의 장점으로 빌딩구조물의 지진해석법으로 널리 사용되고 있지만, 기본 진동모드에 의해서 구조물의 거동이 지배되지 않는 구조물의 경우에는 그 사용성에 대한 연구가 매우 제한적이다. 이를 개선하기 위한 고차모드의 기여분을 반영할 수 있는 비선형 정적 해석법들이 제시 되었지만, 교량 구조물에 사용함에 있어서는 여전히 지진의 특성에 따라 그 사용성 및 신뢰성이 크게 변화하는 문제가 발생한다. 이 논문에서는 지진의 특성을 고려할 수 있는 두가지 지수를 제시하고, 이를 이용하여 비선형정적 해석법의 적용성을 사용단계에서 알아 낼 수 있는지에 대한 연구를 진행하였다.