• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.1641-1649
• /
• 2011

Dynamic response of high-speed railway bridges is important due to the possibility of resonance from continuous and repeated action of high-speed train running. The designer's decision and application affect the result of dynamic analysis significantly, therefore guideline for dynamic analysis is required. On the purpose of the selection of resonable model for dynamic analysis, this study investigated load distribution effect.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
• /
• pp.451-458
• /
• 2001

The structural dynamic responses by wind load consist of alongwind, acrosswind and torsional behavior. Specially, dynamic alongwind response can be obtained from theoretical approach presented by Davenport, Vellozzi and Cohen. Generally the structural dynamic alongwind response can be obtained using the approximate analysis, under the condition that only the first mode shape of the structure is considered and the mode shape is assumed to be a linear function. In this paper, the dynamic alongwind responses are performed by using spectrum of longitudinal velocity fluctuations presented by Davenport and Kaimal, respectively.

• Coupled systems mechanics
• /
• 제9권6호
• /
• pp.563-573
• /
• 2020

Dynamic responses of a laminated composite cantilever beam under a harmonic are investigated in this study. The governing equations of problem are derived by using the Lagrange procedure. The Timoshenko beam theory is considered and the Ritz method is implemented in the solution of the problem. The algebraic polynomials are used with the trivial functions for the Ritz method. In the solution of dynamic problem, the Newmark average acceleration method is used in the time history. In the numerical examples, the effects of load parameter, the fiber orientation angles and stacking sequence of laminas on the dynamic responses of the laminated beam are investigated.

• 대한기계학회논문집A
• /
• 제24권9호
• /
• pp.2220-2227
• /
• 2000

In this paper, dynamic photoelastic hybrid method is developed and its validity is certified. The dynamic photoelastic hybrid method can be used on the obtaining of dynamic stress intensity factors and dynamic stress components. The effect of crack length on the dynamic stress intensity factors is less than those on the static stress intensity factors. When structures are under the dynamic mixed mode load, dynamic stress intensity factor of mode I is almost produced. Dynamic loading device manufactured in this research can be used on the research of dynamic behavior when mechanical resonance is produced and when crack is propagated with the constant velocity.

• Steel and Composite Structures
• /
• 제35권6호
• /
• pp.729-737
• /
• 2020

The goal of this study is to investigate dynamic responses of laminated composite beams under a moving load with thermal effects. The governing equations of problem are derived by using the Lagrange procedure. The transverse-shear strain and rotary inertia are considered within the Timoshenko beam theory. The material properties of laminas are considered as the temperature dependent physical property. The differential equations of the problem are solved by the Ritz method. The solution step of dynamic problem, the Newmark average acceleration method is used in the time history. A compassion study is performed for accuracy of used formulations and method. In the numerical results, the effects of velocity of moving load, temperature values, the fiber orientation angles and the stacking sequence of laminas on the dynamic responses of the composite laminated beam are investigated.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1561-1564
• /
• 2003

In the dynamic analysis model of full vehicles, the ball joint is usually modeled as an ideal joint. Searching a ball joint, the engineering plastic covers metal and the plastic has little compliance. It is expected that the compliance will physically have an influence on load transfer. This thesis presents a dynamic model considering the compliance of a ball joint, and studies an influence related to load transfer. It models the compliance of a ball joint to 3 directional spring. Likewise, it researches the load of a ball joint via a four-post simulation of a full vehicle, comparing with a model considered compliant and the model of an ideal joint. As a result, the difference between the compliance and the ideal joint model was determined. For this reasons, to conduct precision load prediction for durability analysis, dynamic analysis considering the compliance of bali joint should be required.

• 한국기계가공학회지
• /
• 제7권2호
• /
• pp.16-22
• /
• 2008

This study was analyzed dynamically by finite element method about the results of experiments which materials were applied by dynamic load. And they were compared with each other as the simulation data applied onto dynamic impact velocities of 6.4, 16.7 and 18.47m/s. The crack energy release rate, von-Mises stress and the displacement according to the load applied by block were calculated numerically by computer. As the numerical simulation data of specimen analyzed in this study approached the experimental data, the inspection of this specimen model suggested in this paper could be reasonable for the numerical simulation.

• 한국농공학회지
• /
• 제43권4호
• /
• pp.89-96
• /
• 2001

In this study non-linear finite element analysis of dynamic response of steel arch under partially distributed dynamic load was discussed. Material and geometric non-linearities were included in finite element formulation and steel behavior was modeled with Von Mises yield criteria. Either radial or vertical dynamic load was dealt in numerical examples. Normal arch and arch with maximum shape imperfection of L/11,000 were studied. The analysis results showed that maximum displacement at the center of arch was occurred when 70% of arch span was loaded. The maximum displacement at a quarter of arch span was occurred when 50% of arch span was loaded and the displacement was larger than that of center of arch. Ratio of arch rise to arch span within 0.2∼-.3 seems to be appropriate for arch under radial or vertical load.

• Journal of Electrical Engineering and Technology
• /
• 제1권4호
• /
• pp.482-489
• /
• 2006

This paper presents the generalized dynamic modeling of self-excited induction generator (SEIG) using state-space approach. The proposed dynamic model consists of induction generator; self-excitation capacitance and load model are expressed in stationary d-q reference frame with the actual saturation curve of the machine. An artificial neural network model is implemented to estimate the machine magnetizing inductance based on the knowledge of magnetizing current. The dynamic performance of SEIG is investigated under no load, with the load, perturbation of load, short circuit at stator terminals, and variation of prime mover speed, variation of capacitance value by considering the effect of main and cross-flux saturation. During voltage buildup the variation in magnetizing inductance is taken into consideration. The performance of SEIG system under various conditions as mentioned above is simulated using MATLAB/SIMULINK and the simulation results demonstrates the feasibility of the proposed system.

• 대한조선학회지
• /
• 제15권3호
• /
• pp.1-7
• /
• 1978

The dynamic pressures on the bottom of high speed small crafts are studied. Using the dynamic load factor the dynamic pressure can be replaced by equivalent static pressure. Assuming that (1) the system is undamped with a single degree of freedom and (2) the load is applied triangularly, we obtained the max, value of the dynamic load factor of 1.455. We believe that this method could provide a guide to the designer who has no data on the craft in the preliminary structural design stage.