• Title/Summary/Keyword: LS-DYNA

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Design and Analysis of the Swaging Manufacturing Process Using CAE (CAE에 의한 스웨이징(swaging) 제조 공정의 설계 및 해석)

  • Echempati Raghu;Huh Yong-Jeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.5 no.5
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    • pp.442-446
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    • 2004
  • Computer simulation of a swaging manufacturing process is presented in this paper. Commercially available software has been used to develop the simulation algorithm. Based on the experience gained from trial runs, simulation of a tube swaging process has been carried out. The material parameters "n" (strain hardening exponent) and "K" (plastic modulus) are obtained from actual tensile test measurements of the tube material. Two different geometries for the die and the tube have been used in this work and a comparison made. Numerical simulation of the swaging process has been performed using the commercially available HyperMesh(r) for pre-processing, LS-DYNA(r) for analysis and LS-TAURUS(r) for post-processing. Some of the results obtained from this study are compared with those available in the literature.

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Numerical study on the structural response of energy-saving device of ice-class vessel due to impact of ice block

  • Matsui, Sadaoki;Uto, Shotaro;Yamada, Yasuhira;Watanabe, Shinpei
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.3
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    • pp.367-375
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    • 2018
  • The present paper considers the contact between energy-saving device of ice-class vessel and ice block. The main objective of this study is to clarify the tendency of the ice impact force and the structural response as well as interaction effects of them. The contact analysis is performed by using LS-DYNA finite element code. The main collision scenario is based on Finnish-Swedish ice class rules and a stern duct model is used as an energy-saving device. For the contact force, two modelling approaches are adopted. One is dynamic indentation model of ice block based on the pressure-area curve. The other is numerical material modelling by LS-DYNA. The authors investigated the sensitivity of the structural response against the ice contact pressure, the interaction effect between structure and ice block, and the influence of eccentric collision. The results of these simulations are presented and discussed with respect to structural safety.

Manufacturing Technique on the U Type Draw-Bending of Inner Groove Tube (Inner groove tube의 U형 Draw-Bending 가공기술에 관한 연구)

  • Kang, H.S.;Kim, D.S.;Hur, S.;Hong, S.I.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.148-151
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    • 2003
  • The purpose of this study is to investigate the manufacturing technique on the U type Draw-Bending of inner groove tube. The U type tube requires the quality of product that satisfy sufficient conditions for a heat exchanger. The mandrel components act the important roles that prevent wrinkles and keep the shape of cross section of bended tube at bending process. We performed the FEM simulation using LS-DYNA software and the bending test of inner groove tube and then, compared bending simulation with bending test results about mandrel ball diameter, mandrel position and optimal clearance between mandrel and tube.

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A Study of Normalized Smoothed Particle Hydrodynamics (정규 완화입자유동법의 고찰)

  • 박정수;이진성;박희덕;김용석;이재민
    • Journal of the Korea Institute of Military Science and Technology
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    • v.6 no.4
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    • pp.89-99
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    • 2003
  • Smoothed particle hydrodynamics, SPH, is a gridless Lagrangian technique which is a useful alternative numerical analysis method to simulate high velocity deformation problems as well as astrophysical and cosmological problems. The SPH method brings about some difficulties such as tensile Instability and stress oscillation. A new SPH method, so called normalized algorithm, was introduced to overcome these difficulties. In this paper we aimed to estimate this method and have developed an one-dimensional normalized SPH program. The high velocity impact model of an aluminum bar has been analysed by using the developed program and a commercial hydrocode, LS-DYNA. The obtained numerical results showed good agreement with the results of the same model in reference. The program also showed more stable results than those of LS-DYNA in stress oscillation. We hopefully expect that the developed one-dimensional normalized SPH program can be used to solve hydrodynamic problems especially for explosive detonation analysis.

Marine Accident Cause Investigation using M&S System (고도 정밀 M&S 시스템을 이용한 해난사고 원인규명)

  • Lee, Sang-Gab
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2014.06a
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    • pp.36-37
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    • 2014
  • It is necessary to develop highly sophisticated Modeling & Simulation (M&S) system for the scientific investigation of marine accident causes and for the systematic reproduction of accidental damage procedure. To ensure an accurate and reasonable prediction of marine accidental causes, such as collision, grounding and flooding, full-scale ship M&S simulations would be the best approach using hydrocode, such as LS-DYNA code, with its Fluid-Structure Interaction (FSI) analysis technique. The objectivity of this paper is to present three full-scale ship collision, grounding and flooding simulation results of marine accidents, and to show the possibility of the scientific investigation of marine accident causes using highly sophisticated M&S system.

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Passenger Safety Assessment by Real Car Crash Simulation of Composite Post Structures (복합소재 기둥 구조의 실차 충돌 해석에 의한 탑승자 안전성 평가)

  • Kim, Gyu-Dong;Lee, Sang-Youl
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.5 no.2
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    • pp.15-20
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    • 2014
  • This study carried out passenger safety assessment by real car crash simulation of composite post structures for road facilities. The effects of different material properties of composites for various parameters are studied using the LS-DYNA finite element program for this study. In this study, the existing finite element analysis of steel post structures using the LS-DYNA program is further extended to study dynamic behaviors of the structures made of various composite materials. The numerical results for various parameters are verified by comparing different models with displacements and stress distribution occurred in the post and car.

Dynamic Performance Evaluation of Concrete Barrier Systems for Small Vehicle Roadway (소형차 전용도로를 위한 콘크리트 차량방호울타리의 동적성능 평가)

  • Hwang, In-Tae;Lee, Dong-Woo;Choi, Hyun-Ho;Woo, Kwang-Sung
    • International Journal of Highway Engineering
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    • v.14 no.4
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    • pp.113-124
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    • 2012
  • PURPOSES : In This study two different concrete barrier systems have been proposed to be established at the small vehicle driveway. One is for median barrier, and the other is for roadside barrier. METHODS : In order to determine the suitable shape of barrier, the impact parameters including vehicle weight, impact angle, impact velocity and impact level have been analyzed. The real crash test has been carried out with 0.9 ton and 2.5 ton vehicles, respectively by using the 2m segment type concrete barriers connected by steel plates that are totally 40m barrier systems. RESULTS : The numerical results obtained by LS/DYNA-3D software are compared with real crash tests from the viewpoints of vehicle stability, vehicle trajectory, occupant risk, etc. CONCLUSIONS : From the above results, the dynamic performance of proposed barrier systems satisfies the specification of Korean Code for roadside safety structures.

An Analysis for Rollowver Strength of a Medium Bus (중형버스의 전복 강도해석)

  • Min, Han-Ki;Kim, Taeg
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.195-201
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    • 1999
  • In Rollover crashes, the development of bus structure to ensure the maintenance of survival space for passengers is very important . So, this paper focuses on understanding the possibility of efficient structural development considering rollover strength through computer simulation using the commercial code, LS-DYNA3D at the initial stage of vehicle development structural members, and impact boundary conditions required by ADR59(Australian Design Rule 59)were applied. In order to confirm the validity of the computational results, the test results. After the usefulness of this method of analysis was confirmed , we have proposed the effective modificationfor rollover strength.

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Numerical simulation of reinforced concrete slabs under missile impact

  • Thai, Duc-Kien;Kim, Seung-Eock
    • Structural Engineering and Mechanics
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    • v.53 no.3
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    • pp.455-479
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    • 2015
  • This paper presents a numerical analysis of reinforced concrete slabs under missile impact loading. The specimen used for the numerical simulation was tested by the Technical Research Center of Finland. LS-DYNA, commercial available software, is used to analyze the model. The structural components of the reinforced concrete slab, missile, and their contacts are fully modeled. Included in the analysis is material nonlinearity considering damage and failure. The results of analysis are then verified with other research results. Parametric studies with different longitudinal rebar ratios, shear bar ratios, and concrete strengths are conducted to investigate their influences on the punching behavior of slabs under the impact of a missile. Finally, efficient designs are recommended.