• Coupled systems mechanics
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• 제12권4호
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• pp.297-313
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• 2023

This paper deals with delamination analysis of non-linear viscoelastic multilayered beam subjected to bending in the plane of the layers. For this purpose, first, a non-linear viscoelastic model is presented. In order to take into account the non-linear viscoelastic behaviour, a non-linear spring and a non-linear dashpot are assembled in series with a linear spring connected in parallel to a linear dashpot. The behaviours of the non-linear spring and dashpot are described by applying non-linear stress-strain and stress-rate of strain relationships, respectively. The constitutive law of the model is derived. Due to the non-linear spring and dashpot, the constitutive law is non-linear. This law is used for describing the time-dependent mechanical behaviour of the beam under consideration. The material properties involved in the constitutive law vary along the beam length due to the continuous material inhomogeneity of the layers. Solution of the strain energy release rate for the delamination is obtained by analyzing the balance of the energy with considering of the non-linear viscoelastic behaviour. The strain energy release rate is found also by using the complementary strain energy for verification. A parametric study is carried-out by using the solution obtained. The solutions derived and the results obtained help to understand the time-dependent delamination of non-linear viscoelastic beams under loading in the plane of layers.

• 한국CDE학회논문집
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• 제7권1호
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• pp.1-8
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• 2002

A Hotchkiss spring has been widely utilized for commercial vehicle. Usually, the Hotchkiss spring has non-linear characteristics, i.e. it has a piecewise spring stiffness as well as hysterisis phenomenon. Therefore, the modeling of the Hotchkiss spring requires many considerations to fulfill satisfactory vehicle kinematic and dynamic relationships. Also, the spring has difficulties in modeling for presenting contact mechanism. In this paper, the modeling technique for the Hotchkiss spring has been descried. The modeling covers non-linear characteristics as well as contact problems for multi-body dynamic simulation. The force-displacement results are compared with experimental and FEM ones. Also, the comparison between three link type leaf spring model and proposed one has been considered in this paper.

• 소성∙가공
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• 제22권6호
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• pp.303-309
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• 2013

Spring-back of MS1470 steel sheets was numerically predicted using a non-linear kinematic hardening material behavior based on the Yoshida-Uemori model. From uniaxial tension and uniaxial tension-compression-tension data as well as the uniaxial tension-unloading-tension data, the parameters of the Yoshida-Uemori model were obtained. For the numerical simulations, the Yoshida-Uemori model was implemented into the commercial finite element program, ABAQUS/Explicit and ABAQUS/Standard using the user-defined material subroutines. The model performance was validated against the measured spring-back from the benchmark problems of NUMISHEET 2008 and NUMISHEET 2011, the 2-D draw bending test and the S-rail forming test, respectively.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.192-194
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• 2008

• Earthquakes and Structures
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• 제15권3호
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• pp.227-241
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• 2018

The present paper deals with the optimum performance of the passive hybrid control system for the benchmark highway bridge under the six earthquakes ground motion. The investigation is carried out on a simplified finite element model of the 91/5 highway overcrossing located in Southern California. A viscous fluid damper (known as VFD) or non-linear fluid viscous spring damper has been used as a passive supplement device associated with polynomial friction pendulum isolator (known as PFPI) to form a passive hybrid control system. A parametric study is considered to find out the optimum parameters of the PFPI system for the optimal response of the bridge. The effect of the velocity exponent of the VFD and non-linear FV spring damper on the response of the bridge is carried out by considering different values of velocity exponent. Further, the influences of damping coefficient and vibration period of the dampers are also examined on the response of the bridge. To study the effectiveness of the passive hybrid system on the response of the isolated bridge, it is compared with the corresponding PFPI isolated bridges. The investigation showed that passive supplement damper such as VFD or non-linear FV spring damper associated with PFPI system is significantly reducing the seismic response of the benchmark highway bridge. Further, it is also observed that non-linear FV spring damper hybrid system is a more promising strategy in reducing the response of the bridge compared to the VFD associated hybrid system.

• 산업기술연구
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• 제19권
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• pp.31-42
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• 1999

This paper presents a method for evaluating the performance of a leaf spring suspension and an air spring suspension systems for trucks in terms of ride and handling. Leaf springs, which generally have non-linear progressive force-deflection characteristics, are modeled using beam and contact elements. The leaf spring analysis model shows good correlation with experimental results. Each component of an air spring suspension system, which is a single leaf, air spring, height control valve, compressor and linkages, is modeled appropriately. Non-linear characteristics of air spring are accounted for using the measured data, and pressure and volume relations for height control system is also considered. The wheel rate of the air suspension is taken lower but roll stiffness is taken higher than those of leaf springs to improve ride and handling performance, which is verified through driving simulations.

• 한국자동차공학회논문집
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• 제6권6호
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• pp.1-6
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• 1998

A leaf spring plays an important role in a passenger bus. Since characteristic of a leaf spring has a hysteresis behaviour, modeling technique for a leaf spring is an important issue for passenger bus analysis. In this paper, modeling technique for a leaf spring is presented. First, non-linear FEM model of a leaf spring is constructed then it is used to make an approximated model to be used in dynamic analysis. The modeling procedure is ex-plained in step by step approach. Then, this model is applied to dynamic analysis of a mini-bus with flexible body and non-linear dynamic force element. The results are compared with test data.

• 한국소음진동공학회논문집
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• 제15권4호
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• pp.445-451
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• 2005

This paper is the result of a experimental study about non-linear one to one modal coupling of a flexible circular cantilever beam which was transversely excited with harmonic excitation. It was proved that 2 order jumping in out of plane was caused by jump phenomenon in in-plane of flexible circular cantilever beam, because of non-linear coupling. In addition, cantilever beam showed hardening spring characteristics in in-plane and softening spring characteristics in out-of-plane.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.129-133
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• 2004

This paper is the result of a experimental study about non-linear one to one modal coupling of a flexible circular cantilever beam which was transversely excited with harmonic excitation. It was proved that 2 order jumping in out of plane was caused by jump phenomenon in in-plane of flexible circular cantilever beam, because of non-linear coupling. In addition, cantilever beam showed hardening spring characteristics in in-plane and softening spring characteristics in out-of-plane.

• 대한기계학회논문집
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• 제11권3호
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• pp.473-478
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• 1987

본 연구에서는 Newton법에 의한 수치해석을 이용하여 감쇠를 가진 진동계의 최적고유진동수비와 최적감쇠비를 구했으며, 비선형동흡진기가 부착된 진동계의 운동 방정식을 유도하여 조화밸런스법에 의한 진폭비를 산출해서 진폭비에 대한 비선형성의 영향 및 경성스프링과 연성스프링의 특성을 규명하였다.