• Title/Summary/Keyword: ABAQUS user-defined subroutine

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Study on the Void Growth and Coalescence in F.C.C. Single Crystals (F.C.C. 단결정재에서 기공의 성장과 합체에 관한 연구)

  • Ha, Sang-Yul;Kim, Ki-Tae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.4
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    • pp.319-326
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    • 2008
  • In this study, we investigate the deformation behavior of F.C.C. single crystals containing micro- or submicron-sized voids by using three dimensional finite element methods. The locally homogeneous constitutive model for the rate-dependent crystal plasticity is integrated based on the backward Euler method and implemented into a finite element program (ABAQUS) by means of user-defined subroutine (UMAT). The unit cell analysis has been investigated to study the effect of stress triaxiality and crystallographic orientations on the growth and coalescence of voids in F.C.C. single crystals.

Three dimensional finite elements modeling of FGM plate bending using UMAT

  • Messaoudi, Khalid;Boukhalfa, Abdelkrim;Beldjelili, Youcef
    • Structural Engineering and Mechanics
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    • v.66 no.4
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    • pp.487-494
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    • 2018
  • The purpose of the present paper is to study the bending and free vibration of Functionally Graded Material (FGM) plate using user-defined material subroutine on the finite element software ABAQUS. The FGM plate is simply supported and subjected to sinusoidal and uniform load. The Poisson's ratio is kept constant. The results obtained compared to those available in the literature show the convergence, the exactitude and the efficiency of the method used with various power index of the materials.

Design and Analysis of Flap System with Shape Memory Alloy (형상기억합금이 적용된 플랩 시스템의 설계 및 해석)

  • ;Scott R, White;Eric Loth
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.596-599
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    • 1997
  • In this study, the flow control system with shape memory alloy in jet engine inlet was suggested to adjust the shock boundary layer interact~on for supersonic flight system. It consisted of the flap with shape memory alloy, spar with steel, and fixing device with aluminum alloy. The advantages of itself are a simple configuration, a passive air circulation by using the flap deflection due to pressure difference, and no need to be required the auxiliary devices. Finite element analysis was conducted to predict the thenno-mechanical behavlor of the flap system with shape memory alloy. The user-defined subroutine UMAT was implemented with ABAQUS to accon~modate the thermo-mechanical constitutive relation of shape memory alloy.

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Practical Nonlinear FE Analysis of Concrete Beam Considering Material Nonlinearity (재료비선형을 고려한 콘크리트 보의 실용적인 유한요소해석)

  • Chung, Won-Seok
    • Journal of the Korean Society for Railway
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    • v.9 no.6 s.37
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    • pp.778-783
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    • 2006
  • This study investigates the ultimate behavior of reinforced concrete beams by means of practical nonlinear finite element (FE) analyses. Uniaxial constitutive models for the concrete and steel material are selected in this study. The adopted material model is integrated into the ABAQUS fiber beam elements through a user-defined material subroutine (UMAT). Within a developed nonlinear finite element framework, the FE results have been compared to experimental results reported by other researchers. It has been found that the proposed finite element model is capable of predicting the initial cracking load level, the yield load, the ultimate load, and the crack distribution with acceptable accuracy.

Finite element-based software-in-the-loop for offline post-processing and real-time simulations

  • Oveisi, Atta;Sukhairi, T. Arriessa;Nestorovic, Tamara
    • Structural Engineering and Mechanics
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    • v.67 no.6
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    • pp.643-658
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    • 2018
  • In this paper, we introduce a new framework for running the finite element (FE) packages inside an online Loop together with MATLAB. Contrary to the Hardware-in-the-Loop techniques (HiL), in the proposed Software-in-the-Loop framework (SiL), the FE package represents a simulation platform replicating the real system which can be out of access due to several strategic reasons, e.g., costs and accessibility. Practically, SiL for sophisticated structural design and multi-physical simulations provides a platform for preliminary tests before prototyping and mass production. This feature may reduce the new product's costs significantly and may add several flexibilities in implementing different instruments with the goal of shortlisting the most cost-effective ones before moving to real-time experiments for the civil and mechanical systems. The proposed SiL interconnection is not limited to ABAQUS as long as the host FE package is capable of executing user-defined commands in FORTRAN language. The focal point of this research is on using the compiled FORTRAN subroutine as a messenger between ABAQUS/CAE kernel and MATLAB Engine. In order to show the generality of the proposed scheme, the limitations of the available SiL schemes in the literature are addressed in this paper. Additionally, all technical details for establishing the connection between FEM and MATLAB are provided for the interested reader. Finally, two numerical sub-problems are defined for offline and online post-processing, i.e., offline optimization and closed-loop system performance analysis in control theory.

Finite Element Analysis Through Mechanical Property Test and Elasto-plastic Modeling of 2.5D Cf/SiCm Composite Analysis (2.5D Cf/SiCm 복합재의 기계적 물성 시험과 탄소성 모델링을 통한 유한요소해석)

  • Lee, MinJung;Kim, Yeontae;Lee, YeonGwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.9
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    • pp.663-670
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    • 2020
  • A study on mechanical property characterization and modeling technique was carried out to approximate the behaviour of structures with 2.5D C/SiC material. Several tensile tests were performed to analyze the behaviour characteristics of the 2.5D C/SiC material and elastic property was characterized by applying a mathematical homogenization and a modified rule of mixture. SiC matrix representing the elasto-plastic behavior approximates as a bilinear function. Then the equivalent yield strength and equivalent plastic stiffness were calculated by minimizing errors in experiment and approximation. RVE(Representative Volume Element)was defined from the fiber and matrix configuration of 2.5D C/SiC and a process of calculating the effective stiffness matrix by applying the modified rule of mixture to RVE was implemented in the ABAQUS User-defined subroutine. Finite element analysis was performed by applying the mechanical properties of fiber and matrix calculated based on the proposed process, and the results were in good agreement with the experimental results.

A 3D RVE model with periodic boundary conditions to estimate mechanical properties of composites

  • Taheri-Behrooz, Fathollah;Pourahmadi, Emad
    • Structural Engineering and Mechanics
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    • v.72 no.6
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    • pp.713-722
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    • 2019
  • Micromechanics is a technique for the analysis of composites or heterogeneous materials which focuses on the components of the intended structure. Each one of the components can exhibit isotropic behavior, but the microstructure characteristics of the heterogeneous material result in the anisotropic behavior of the structure. In this research, the general mechanical properties of a 3D anisotropic and heterogeneous Representative Volume Element (RVE), have been determined by applying periodic boundary conditions (PBCs), using the Asymptotic Homogenization Theory (AHT) and strain energy. In order to use the homogenization theory and apply the periodic boundary conditions, the ABAQUS scripting interface (ASI) has been used along with the Python programming language. The results have been compared with those of the Homogeneous Boundary Conditions method, which leads to an overestimation of the effective mechanical properties. According to the results, applying homogenous boundary conditions results in a 33% and 13% increase in the shear moduli G23 and G12, respectively. In polymeric composites, the fibers have linear and brittle behavior, while the resin exhibits a non-linear behavior. Therefore, the nonlinear effects of resin on the mechanical properties of the composite material is studied using a user-defined subroutine in Fortran (USDFLD). The non-linear shear stress-strain behavior of unidirectional composite laminates has been obtained. Results indicate that at arbitrary constant stress as 80 MPa in-plane shear modulus, G12, experienced a 47%, 41% and 31% reduction at the fiber volume fraction of 30%, 50% and 70%, compared to the linear assumption. The results of this study are in good agreement with the analytical and experimental results available in the literature.

Numerical Simulation of Membrane of LNG Insulation System using User Defined Material Subroutine (사용자지정 재료 서브루틴을 활용한 LNG선박 단열시스템 멤브레인의 수치해석)

  • Kim, Jeong-Hyeon;Kim, Seul-Kee;Kim, Myung-Soo;Lee, Jae-Myung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.4
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    • pp.265-271
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    • 2014
  • 304L stainless steel sheets are used as a primary barrier for the insulation of membrane-type liquefied natural gas(LNG) carrier cargo containment system. 304L stainless steel is a transformation-induced-plasticity(TRIP) steel that exhibits complex material behavior, because it undergoes phase transformation during plastic deformation. Since the TRIP behavior is very important mechanical characteristics in a low-temperature environment, significant amounts of data are available in the literature. In the present study, a uniaxial tensile test for 304L stainless steel was performed to investigate nonlinear mechanical characteristics. In addition, a viscoplastic model and damage model is proposed to predict material fractures under arbitrary loads. The verification was conducted not only by a material-based comparative study involving experimental investigations, but also by a structural application to the LNG membrane of a Mark-III-type cargo containment system.

Analysis of Damaged Material Response Using Unified Viscoplastic Constitutive Equations (통합형 점소성구성식을 이용한 손상재료거동해석)

  • Ha Sang Yul;Kim Ki Tae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.2 s.233
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    • pp.253-261
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    • 2005
  • In decades, a substantial body of work on a unified viscoplastic model which considers the mechanism of plastic deformation and creep deformation has developed. The systematic scheme for numerical analysis of unified model is necessary because the dominant failure mechanism is the defect growth and coalescence in materials. In the present study, the unified viscoplastic model for materials with defects suggested by Suquet and Michel was employed for numerical analysis. The constitutive equations are integrated based on the generalized mid-point rule and implemented into a finite element program (ABAQUS) by means of user-defined subroutine (UMAT). To evaluate the validity of the developed UMAT code and the assessment of the adopted viscoplastic model, the results obtained from the UMAT code was compared with the numerical reference solution and experimental data. The unit cell analysis also has been investigated to study the effect of strain rate, temperature, stress triaxiality and initial defect volume fraction on the growth and coalescence of the defect.

Numerical modeling of the damaged cement orthopedic in three variants of total hip prostheses

  • Cherfi Mohamed;Zagane Mohammed El Sallah;Moulgada Abdelmadjid;Ait Kaci Djafar;Benouis Ali;Zahi Rachid;Sahli Abderahmen
    • Structural Engineering and Mechanics
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    • v.91 no.3
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    • pp.251-262
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    • 2024
  • Numerical modeling using the finite element method (FEM) offers crucial insights into the mechanical behavior of prostheses, including stress and strain distribution, load transfer, and stress intensity factors. Analyzing cracking in PMMA surgical cement (polymethylmethacrylate) for total hip prostheses (THP) is essential for understanding the loosening phenomenon, as the rupture of orthopedic cement is a primary cause. By understanding various failure mechanisms, significant advancements in cemented total prostheses can be achieved. This study performed a numerical analysis using a 3D FEM model to evaluate stress levels in different THP models, aiming to model damage in the orthopedic cement used in total hip arthroplasty. Utilizing ABAQUS software, FEM, and XFEM, the damage in three types of THPs-Charnley (CMK3), Osteal (BM3), and THOMPSON was modeled under stumbling loading conditions. XFEM allowed for the consideration of crack propagation between the cement and bone, while the GEARING criterion employed a user-defined field subroutine to model damage parameters. The study's findings can contribute to improving implant fixation techniques and preventing postoperative complications in orthopedic surgery.