• Title/Summary/Keyword: hybrid finite element model

Search Result 183, Processing Time 0.032 seconds

Hybrid Two-Dimensional Finite Element Model of Tires (타이어의 복합 이차원 유한 요소 모델)

  • Kim, Yong-Joe;Bolton, J.Stuart
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2002.11b
    • /
    • pp.62-67
    • /
    • 2002
  • It has been shown that the vibrational response of a tire can be represented by a set of decaying waves, each associated with a particular cross-sectional mode shape in the region near the contact patch. Thus, it can be concluded that tires can be effectively modeled as lossy waveguides. It has also been shown that the sound radiation from tires is mainly from the region close to the contact patch. In consequence, it may be computationally efficient to analyze tire vibration and sound radiation in the region close to the contact patch by using a hybrid finite element model in which the cross-section of a tire is approximated by 2-D finite elements while an analytical wave solution is assumed in the circumferential direction of the tire. In this article. a hybrid finite element was formulated based on a composite shell model. The dispersion relations for sample structures obtained by using the hybrid FE model were then compared with those obtained by using a full, three-dimensional FE model. It has been shown that the FE analysis made using the hybrid 2-D finite elements yields results in close agreement with the three-dimensional model.

  • PDF

Fatigue behavior of hybrid GFRP-concrete bridge decks under sagging moment

  • Xin, Haohui;Liu, Yuqing;He, Jun;Fan, Haifeng;Zhang, Youyou
    • Steel and Composite Structures
    • /
    • v.18 no.4
    • /
    • pp.925-946
    • /
    • 2015
  • This paper presents a new cost-effective hybrid GFRP-Concrete deck system that the GFRP panel serves as both tensile reinforcement and stay-in-place form. In order to understand the fatigue behavior of such hybrid deck, fatigue test on a full-scale specimen under sagging moment was conducted, and a series of static tests were also carried out after certain repeated loading cycles. The fatigue test results indicated that such hybrid deck has a good fatigue performance even after 3.1 million repeated loading cycles. A three-dimensional finite element model of the hybrid deck was established based on experimental work. The results from finite element analyses are in good agreement with those from the tests. In addition, flexural fatigue analysis considering the reduction in flexural stiffness and modulus under cyclic loading was carried out. The predicted flexural strength agreed well with the analytical strength from finite element simulation, and the calculated fatigue failure cycle was consistent with the result based on related S-N curve and finite element analyses. However, the flexural fatigue analytical results tended to be conservative compared to the tested results in safety side. The presented overall investigation may provide reference for the design and construction of such hybrid deck system.

Spring-Back Prediction for Sheet Metal Forming Process Using Hybrid Membrane/shell Method (하이브리드 박막/쉘 방법을 이용한 박판성형공정의 스프링백 해석)

  • 윤정환;정관수;양동열
    • Transactions of Materials Processing
    • /
    • v.12 no.1
    • /
    • pp.49-59
    • /
    • 2003
  • To reduce the cost of finite element analyses for sheet forming, a 3D hybrid membrane/shell method has been developed to study the springback of anisotropic sheet metals. In the hybrid method, the bending strains and stresses were analytically calculated as post-processing, using incremental shapes of the sheet obtained previously from the membrane finite element analysis. To calculate springback, a shell finite element model was used to unload the final shape of the sheet obtained from the membrane code and the stresses and strains that were calculated analytically. For verification, the hybrid method was applied to predict the springback of a 2036-T4 aluminum square blank formed into a cylindrical cup. The springback predictions obtained with the hybrid method was in good agreement with results obtained using a full shell model to simulate both loading and unloading and the experimentally measured data. The CPU time saving with the hybrid method, over the full shell model, was 75% for the punch stretching problem.

Spring-back prediction for sheet metal forming process using hybrid membrane/shell method (하이브리드 박막/쉘 방법을 이용한 박판성형공정의 스프링백 해석)

  • F. Pourboghrat
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1999.03b
    • /
    • pp.62-65
    • /
    • 1999
  • To reduce the cost of finite element analyses for sheet forming a 3D hybrid membrance/sheel method has been developed to study the springback of anisotropic sheet metals. in the hybrid method the bending strains and stresses were analytically calculated as post-processing using incremental shapes of the sheet obtained previously from the membrane finite element analysis. To calculate springback a shell finite element model was used to unload the final shape of the sheet obtained from the membran code and the stresses and strains that were calculated analytically. For verification the hybrid method was applied to predict the springback of a 2036-T4 aluminum square blank formed into a cylindrical cup. the springback predictions obtained with the hybrid method was in good agreement with results obtained using a full shell model to simulateboth loading an unloading and the experimentally measured data. The CPU time saving with the hybrid method over the full shell model was 75% for the punch stretching problem.

  • PDF

Finite Element Analysis on the Strength Safety of a Hybrid Alarm Valve (복합알람밸브의 강도안전성에 관한 유한요소해석)

  • Kim, Chung-Kyun;Kim, Tae-Hwan
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.21 no.2
    • /
    • pp.221-224
    • /
    • 2012
  • This paper presents the strength safety of a hybrid alarm valve by a finite element analysis. The stress and strain of a conventional hybrid alarm valve are calculated for the given maximum test pressure of 2MPa. Especially, the FEM computed maximum stress of a conventional hybrid valve is only 18.6% of yield strength, 370MPa. This means that the conventional valve is designed with a thick thickness of a valve structure. But, new hybrid alarm valve model, which is developed by optimized design method in this study, shows more low level of 43% in maximum stress and strain compared with that of a conventional hybrid valve. These results may recommend the reduction of a weight and a dimension for an optimized hybrid alarm valve.

Bending Performance Evaluation of Aluminum-Composite Hybrid Square Tube Beams (알루미늄-복합재료 혼성 사각관 보의 굽힘 성능평가)

  • Lee, Sung-Hyuk;Choi, Nak-Sam
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2005.04a
    • /
    • pp.76-79
    • /
    • 2005
  • Bending deformation and energy absorption characteristics of aluminum-composite hybrid tube beams have been analyzed for improvement in the bending performance of aluminum space frame by using experimental tests combined with theoretical and finite element analyses. Hybrid tube beams composed of glass fabric/epoxy layer wrapped around on aluminum tube were made in autoclave with the recommended curing cycle. Basic properties of aluminum material used for initial input data of the finite element simulation and theoretical analysis were obtained from the true stress-true strain curve of specimen which had bean extracted from the Al tube beam. A modified theoretical model was developed to predict the resistance to the collapse of hybrid tube beams subjected to a bending load. Theoretical moment-rotation angle curves of hybrid tube beams were in good agreement with experimental ones, which was comparable to the results obtained from finite element simulation. Hybrid tube beams strengthened by composite layer on the whole web and flange showed an excellent bending strength and energy absorption capability.

  • PDF

Computational analysis of sandwich shield with free boundary inserted fabric at hypervelocity impact (비구속 삽입된 직물 섬유를 이용한 샌드위치 쉴드의 초고속 충격 해석)

  • Moon, Jin-Bum;Park, Yu-Rim;Son, Gil-Sang;Kim, Chun-Gon
    • Composites Research
    • /
    • v.24 no.3
    • /
    • pp.31-38
    • /
    • 2011
  • In this paper, a novel hybrid composite shield to protect space structures from hypervelocity impact of micrometeoroid and space debris is proposed. The finite element model of the proposed shield was constructed and finite element analysis was conducted to approximate the energy absorption rate. Before the final model analysis, analysis of each component including the aluminum plate, PMMA plate, and intermediate layer of fabric was performed, verifying the finite element model of each component. The material properties used in the analyses were predicted material property values for high strain rates. The analysis results showed that, other than the fabric, the energy absorption rate of each component was in agreement. Afterwards, the finite element model of the hybrid composite shield was constructed, where it was analyzed for the restrained and unrestrained fabric boundary condition cases. Through the finite element analysis, the fiber pullout mechanism was realized for the hybrid shield with free boundary inserted fabric, and it was observed that this mechanism led to energy absorption increase.

Development of Finite Element Model of Hybrid III 5th Percentile Female Dummy (Hybrid III 5% 성인 여성 더미의 유한요소 모델 개발)

  • Yi, Sang-Il;Mohan, Pradeep K.;Kan, Cing-Dao Steve;Park, Gyung-Jin
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.18 no.4
    • /
    • pp.18-30
    • /
    • 2010
  • As the automobile industry is developing, the number of deaths and injuries has increased. To reduce the damages from automobile accidents, the government of each country proposes experimental conditions for reproducing the accident and establishes the vehicle safety regulations. Automotive manufacturers are trying to make safer vehicles by satisfying the requirements. The Hybrid III crash test dummy is a standard Anthropomorphic Test Device (ATD) used for measuring the occupant's injuries in a frontal impact test. Since a real crash test using a vehicle is fairly expensive, a computer simulation using the Finite Element Method (F.E.M.) is widely used. Therefore, a detailed and robust F.E. dummy model is needed to acquire more accurate occupant injury data and behavior during the crash test. To achieve this goal, a detailed F.E. model of the Hybrid III 5th percentile female dummy is constructed by using the reverse engineering technique in this research. A modeling process is proposed to construct the F.E. model. The proposed modeling process starts from disassembling the physical dummy. Computer Aided Design (CAD) geometry data is constructed by three-dimensional (3-D) scanning of the disassembled physical dummy model. Based on the geometry data, finite elements of each part are generated. After mesh generation, each part is assembled with other parts using the joints and rigid connection elements. The developed F.E. model of dummy is simulated based on the FMVSS 572 validation regulations. The results of simulation are compared with the results of physical tests.

Comparative structural analysis of lattice hybrid and tubular wind turbine towers

  • Kumaravel, R.;Krishnamoorthy, A.
    • Wind and Structures
    • /
    • v.30 no.1
    • /
    • pp.29-35
    • /
    • 2020
  • This paper presents a comparative structural analysis of lattice hybrid tower with six legs with conventional tubular steel tower for an onshore wind turbine using finite element method. Usually a lattice hybrid tower will have a conventional industry standard 'L' profile section for the lattice construction with four legs. In this work, the researcher attempted to identify and analyze the strength of six legged lattice hybrid tower designed with a special profile instead of four legged L profile. And to compare the structural benefits of special star profile with the conventional tubular tower. Using Ansys, a commercial FEM software, both static and dynamic structural analyses were performed. A simplified finite element model that represents the wind turbine tower was created using Shell elements. An ultimate load condition was applied to check the stress level of the tower in the static analysis. For the dynamic analysis, the frequency extraction was performed in order to obtain the natural frequencies of the tower.

Evolutionary-base finite element model updating and damage detection using modal testing results

  • Vahidi, Mehdi;Vahdani, Shahram;Rahimian, Mohammad;Jamshidi, Nima;Kanee, Alireza Taghavee
    • Structural Engineering and Mechanics
    • /
    • v.70 no.3
    • /
    • pp.339-350
    • /
    • 2019
  • This research focuses on finite element model updating and damage assessment of structures at element level based on global nondestructive test results. For this purpose, an optimization system is generated to minimize the structural dynamic parameters discrepancies between numerical and experimental models. Objective functions are selected based on the square of Euclidean norm error of vibration frequencies and modal assurance criterion of mode shapes. In order to update the finite element model and detect local damages within the structural members, modern optimization techniques is implemented according to the evolutionary algorithms to meet the global optimized solution. Using a simulated numerical example, application of genetic algorithm (GA), particle swarm (PSO) and artificial bee colony (ABC) algorithms are investigated in FE model updating and damage detection problems to consider their accuracy and convergence characteristics. Then, a hybrid multi stage optimization method is presented merging advantages of PSO and ABC methods in finding damage location and extent. The efficiency of the methods have been examined using two simulated numerical examples, a laboratory dynamic test and a high-rise building field ambient vibration test results. The implemented evolutionary updating methods show successful results in accuracy and speed considering the incomplete and noisy experimental measured data.