유연 다물체 동역학 모델을 이용한 판스프링의 이력현상 및 동응력해석

문일동(Ildong Moon),김기태(Gitae Kim),임정환(Junghwan Lim),오재윤(Chaeyoun Oh) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper proposes a modeling technique which is able to not only reliably and easily represent the hysteretic characteristic but also analyze the dynamic stress of a taper leaf spring. The flexible multi-body dynamic model of the taper leaf spring is developed by interfacing the finite element model and computation model of the taper leaf spring. Rigid dummy parts are attached at the places where a finite element leaf model is in contact with an adjacent one in order to apply contact model. Friction is defined in the contact model to represent the hysteretic phenomenon of the taper leaf spring. The test of the taper leaf spring is conducted for the validation of the reliability of the flexible multi-body dynamic model of the taper leaf spring developed in this paper. The test is started at an unloaded state with the excitation amplitude of 1-2㎜/sec and frequency of 132㎜. First, the simulation is conducted with the same condition as the test. Then, the simulations are conducted with various amplitudes in a loaded state. The hysteretic diagram from the test is compared with the ones from the simulation for the validation of the reliability of the model. The dynamic stress analysis of the taper leaf spring is also conducted with the developed flexible multi-body dynamic model under a dynamic loading condition.

스프링조작기의 동특성 예측을 위한 유한요소 스프링 모델의 탄성효과

손정현(Jeonghyun Sohn),이승규(Seungkyu Lee) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

In this study, Since the performance of the circuit breaker depends on the spring operating mechanism, the accurate analysis of the spring operating mechanism should be required. The spring, especially closing spring, stores the deformation energy due to the compression and then accelerates the big loads rapidly in the circuit breaker. To accurately carry out the kinematic and dynamic analysis of the circuit breaker, the accurate modeling of the spring behavior is needed. Finite element spring model is compared with the experimental results under the instant release condition. Numerical accuracy between the linear model and finite element model is compared with the experimental results. In addition, flexible effects of finite element spring model for spring operating mechanism are investigated.

스프링조작기를 가진 고압회로차단기의 스프링 모델링에 관한 연구

이승규(Seung-Kyu Lee),김승오(Seung-Oh Kim),유완석(Wan-Suk Yoo),손정현(Jeong-Hyun Sohn) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

Since the performance of the circuit breaker mainly depends on the spring operating mechanism, the analysis of the spring operating mechanism is required. The spring, especially closing spring, stores the deformation energy due to the compression and then accelerates the big loads rapidly in the circuit breaker. To accurately carry out the kinematic and dynamic analysis of the circuit breaker, the precise modeling of the spring behavior is necessary. In this paper, the static stiffness of the spring is captured by using the tester. When the spring is used in the circuit breaker, it is installed horizontally. Therefore, Sine excitation tests are carried out horizontal and vertical direction. Three types of spring models such as a linear spring model, modal spring model, and nodal spring model are suggested and compared with the experimental results.

다물체 동역학 해석을 통한 맥퍼슨 스트럿 서스펜션 사이드 로드 스프링의 승차감 개선 효과 분석

장형배,한창수 대한기계학회 2020 大韓機械學會論文集A Vol.44 No.8

Nonlinear finite element analysis is generally used in analyzing the side load spring applied to MacPherson strut suspension. However, this analysis often takes prolonged time for model setup and solving. In this paper, a method of modeling nonlinear finite element components using absolute nodal coordinate formulation is described and applied in a multibody dynamics model. In addition, a method of developing a jig model for converting an unloaded side load spring to a loaded spring is presented. The results obtained using this method are applied to half-vehicle and fullvehicle models in performing multibody dynamics simulation. Through these analyses, the effectiveness analysis of side load springs, which is difficult or time-consuming to implement through conventional finite element analysis, can be carried out faster and more efficiently. 맥퍼슨 스트럿 서스펜션에 적용되는 사이드 로드 스프링을 해석하기 위해서는 일반적으로 비선형 유한요소 해석이 사용된다. 그러나 비선형 유한요소 해석은 모델링 및 해석에 많은 시간이 소요되는 경우가 많다. 본 논문에서는 절대절점좌표계를 이용하여 비선형 유한 요소를 모델링하고, 이를 다물체 동역학 모델에 적용하여 해석하는 방법을 설명한다. 그리고 하중을 받지 않은 상태로 설계된 사이드 로드 스프링을 차량에 장착된 상태로 전환하기 위한 지그 모델을 구성하는 방법을 제시하고, 이 결과를 반차량 및 전차량 모델에 적용하여 다물체 동역학 해석을 수행한다. 이러한 해석들을 통하여, 기존의 유한요소 해석을 통해서는 구현하기 힘들거나 시간이 많이 걸리는 사이드 로드 스프링의 효과 분석을 보다 쉽고 빠르게 수행할 수 있다.

맥퍼슨 스트럿 서스펜션 사이드 로드 스프링의 해석적 설계 및 옵셋 최적화

장형배,한창수 대한기계학회 2020 大韓機械學會論文集A Vol.44 No.8

Side load springs are used to counteract the bending moments acting on the damper of a MacPherson strut suspension, thereby reducing the friction between the damper parts and improving ride comfort. In this paper, the equations and processes of analytically designing side load springs are summarized, and equations for smoothly connecting the seat coil and active coil and the optimization method of offset are presented. Additionally, the designed side load spring based on this process is verified through multibody dynamics simulation by applying nonlinear finite elements using absolute nodal coordinate formulation. Through this simulation, it is confirmed that the side load spring is effective in improving the ride comfort of a MacPherson strut suspension compared to conventional coil springs. 맥퍼슨 스트럿 서스펜션의 댐퍼에 작용하는 굽힘 모멘트를 상쇄시킴으로써, 댐퍼 부품 간의 마찰을 줄이고 승차감을 향상시키기 위하여 사이드 로드 스프링이 사용된다. 본 논문에서는 사이드 로드 스프링을 해석적으로 설계하기 위한 수식 및 프로세스를 정리하고, 좌권부와 활성 코일부를 부드럽게 연결하기 위한 수식과 옵셋 최적화 방법을 제시한다. 그리고 이를 바탕으로 설계된 사이드 로드 스프링을 절대절점좌표계를 이용한 비선형 유한 요소를 적용한 다물체 동역학 해석을 통하여 검증해 본다. 이러한 해석을 통하여 기존의 코일 스프링과 비교하여 사이드 로드 스프링이 맥퍼슨 스트럿 서스펜션의 승차감 향상에 효과가 있음을 확인할 수 있다.

스프링타입 진공회로차단기의 거동 시뮬레이션

박석천(Seokcheon Park),장진석(Jinsuk Jang),손정현(Jeonghyun Sohn) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

In this study, a dynamic model of spring type vacuum circuit breaker (VCB) is established for analyzing the dynamic behavior. Closing and tripping springs are used to generate the closing and opening motion of VCB. Since the performance of the circuit breaker mainly relies on the spring operating mechanism, the analysis of the spring operating mechanism is required for advanced designs. In this study, the spring is considered as a flexible body in the computer modeling. To get the modeling parameters, the characteristic tests for springs and rubber pad are performed. The operating mechanism of VCB is modeled by using RecurDyn program. The closing and opening motion are carried out and analyzed.

스프링-댐퍼를 갖는 슬로싱 유동의 유체-다물체동역학 연성 시뮬레이션

김성필,박종천,손정현 한국전산유체공학회 2017 한국전산유체공학회지 Vol.22 No.4

In recent, a lot of interesting and challenging attempts have been reported to reduce sloshing loads in a tank, such as baffle, floaters and perforated panels, etc. Because the sloshing phenomena represents random and highly nonlinear behaviors, which makes the analysis extremely difficult and lead to a new level for challenging at the moment, the prediction and mitigation of sloshing impact have often been dependant on experiments and statistical analysis. In a past few decades, some numerical methods have been suggested and applied to solve the sloshing phenomena while computer performance and numerical techniques are rapidly improved. In the preset study, a series of experiments and numerical simulation are performed to understand the sloshing behavior of fluids interacting with two horizontal plates connected to springs to the top of the tank as damping system, and examine the mitigation effects of sloshing impact. For the numerical simulation, a coupled system of Smoothed Particle Hydrodynamics (SPH) for solving fluid motion and Multibody Dynamics (MBD) for dynamic movements of mechanism system has been developed. The simulation results are compared with those of experiments for validating the developed numerical system, and the mitigation effects of sloshing due to the spring-linked damping systems are discussed.

오르간 액셀페달의 스프링상수에 따른 답력특성 연구

박경민,정석훈,박상현 한국기계기술학회 2015 한국기계기술학회지 Vol.17 No.6

It analyzes the new structure and mechanism of organ type accel pedal to have a double curve to obtain a low effort force has been devised an electronic accel pedal consisting of two springs. To confirm the characteristics of effort force on variation of spring constants for two springs, dynamic analyzes were performed by using the ADAMS software program. According to the result of the simulation analysis, new mechanism of organ type accel pedal has an inflection point of the curve of pedal effort force on variation of spring constants, k, in various range of pedal angle.

2단계 강성을 가지는 점증형 스프링의 모델링 파라미터화

김채원(Chae Won Kim),오은호(Eunho Oh),강오성(Ohsung Kang) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

Rear mass change shows much more than in front due to lighter curb and higher payload including several passengers and luggage, especially for small cars or multi-purpose vehicles (MPV). In order to ensure ride comfort, vehicle handling and structural load manageability, well-designed vertical force characteristics is required on the rear suspension. A progressive nonlinear coil spring enables the suspension to keep consistent ride frequency. In that case, two spring rates are selected as main design parameters. Above on that, two more parameters are needed to describe the progression curve. In total, four independent parameters are selected as key design factors for the dual-rate progressive spring. Selected parameters and an interpolation curve are implemented within ADAMS/View dynamics software. The parameterized model shows well correlated with physical measured spring force-deflection curve and enables frequent suspension design reviews on time.

삼각형 메쉬에서 안정적인 옷감 시뮬레이션을 하기 위한 LOD 적응형 굽힘 스프링을 이용한 변형률 기반 동역학

김종현 한국컴퓨터정보학회 2023 韓國컴퓨터情報學會論文誌 Vol.28 No.9

This paper describes a level of detail (LOD) based bending spring structure and damping technique that can reliably represent strain-based dynamics (SBD) on a triangular mesh. SBD models elastic energy using strain instead of energy based on the edge length of a triangular mesh. However, when a large external force occurs, the process of calculating the elastic energy based on edges results in a degenerate triangle, which stretches in the wrong direction because it calculates an unstable strain. In this paper, we introduce an LOD-based bending spring generation and energy calculation method that can efficiently handle this problem. As a result, the technique proposed in this paper can reliably and efficiently handle SBD based on bending springs, which can provide a stable representation of cloth simulation.