• Title, Summary, Keyword: cyclic plasticity

Search Result 99, Processing Time 0.038 seconds

Evaluation of AF type cyclic plasticity models in ratcheting simulation of pressurized elbow pipes under reversed bending

  • Chen, Xiaohui;Gao, Bingjun;Chen, Xu
    • Steel and Composite Structures
    • /
    • v.21 no.4
    • /
    • pp.703-753
    • /
    • 2016
  • The ratcheting behavior was studied experimentally for Z2CND18.12N elbow piping under cyclic bending and steady internal pressure. Dozens of cyclic plasticity models for structural ratcheting responses simulations were used in the paper. The four models, namely, Bilinear (BKH), Multilinear (MKIN/KINH), Chaboche (CH3), were already available in the ANSYS finite element package. Advanced cyclic plasticity models, such as, modified Chaboche (CH4), Ohno-Wang, modified Ohno-Wang, Abdel Karim-Ohno and modified Abdel Karim-Ohno, were implemented into ANSYS for simulating the experimental responses. Results from the experimental and simulation studies were presented in order to demonstrate the state of structural ratcheting response simulation by these models. None of the models evaluated perform satisfactorily in simulating circumferential strain ratcheting response. Further, improvement in cyclic plasticity modeling and incorporation of material and structural features, like time-dependent, temperature-dependent, non-proportional, dynamic strain aging, residual stresses and anisotropy of materials in the analysis would be essential for advancement of low-cycle fatigue simulations of structures.

Formulation of Cyclic Plasticity Model and FE Analysis for SM490 TMC (SM490 TMC 강재의 반복소성모델의 정식화 및 유한요소해석)

  • 장갑철;장경호
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.84-89
    • /
    • 2004
  • In this paper, cyclic plasticity model of SM490 TMC was formulated by basing on monotonic loading test and cyclic loading test. For exact description of cyclic performance and plastic deformation capacity of steel member using SM490 TMC, formulated cyclic plasticity model and finite deformation theory were applied to 3-dimensional elastic-plastic FE analysis. Cyclic plastic behavior of pipe-section steel column using SM490 TMC was clarified by carrying out numerical analysis. Also, in order to clarifying seismic performance of pipe-section steel column using SM490 TMC, analysis results were compared with analysis results of pipe-section steel column using SM490. A comparison of analysis results shows that SM490 TMC pipe-section steel column has a better cyclic performance for strength and energy dissipation than SM490 pipe-section steel column under cyclic loading

  • PDF

Full-range plasticity of novel high-performance low-cost stainless steel QN1803

  • Zhou, Yiyi;Chouery, Kim Eng;Xie, Jiang-Yue;Shu, Zhan;Jia, Liang-Jiu
    • Steel and Composite Structures
    • /
    • v.35 no.6
    • /
    • pp.739-752
    • /
    • 2020
  • This paper aims to investigate cyclic plasticity of a new type of high-performance austenitic stainless steel with both high strength and high ductility. The new stainless steel termed as QN1803 has high nitrogen and low nickel, which leads to reduction of cost ranging from 15% to 20%. Another virtue of the new material is its high initial yield strength and tensile strength. Its initial yield strength can be 40% to 50% higher than conventional stainless steel S30408. Elongation of QN1803 can also achieve approximately 50%, which is equivalent to the conventional one. QN1803 also has a corrosion resistance as good as that of S30408. In this paper, both experimental and numerical studies on the new material were conducted. Full-range true stress-true strain relationships under both monotonic and cyclic loading were obtained. A cyclic plasticity model based on the Chaboche model was developed, where a memory surface was newly added and the isotropic hardening rule was modified. A user-defined material subroutine was written, and the proposed cyclic plasticity model can well evaluate full-range hysteretic properties of the material under various loading histories.

Crystal Plasticity Simulation of Ti-6Al-4V Under Fretting Fatigue (프레팅 피로를 받는 Ti-6Al-4V의 결정소성 시뮬레이션)

  • Goh Chung Hyun;Lee Kee Seok;Ko Jun Bin
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.29 no.4
    • /
    • pp.511-517
    • /
    • 2005
  • Fretting fatigue is often the root cause of the nucleation of cracks at attachments of structural components. Since fretting fatigue damage accumulation occurs over relatively small volumes, the subsurface cyclic plastic strain is expected to be rather non-uniformly distributed in polycrystalline materials. The scale of the cyclic plasticity and the damage process zones is often on the order of microstructure dimensions. Fretting damage analyses using cyclic crystal plasticity constitutive models have the potential to account for the influence of size, morphology, and crystallographic orientation of grains on fretting damage evolution. Two-dimensional plane strain simulations of fretting fatigue are performed using the cyclic properties of Ti-6Al-4V. The crystal plasticity simulations are compared to an initially isotropic $J_{2}$ theory with nonlinear kinematic hardening as well as to experiments. The influence of initially isotropic versus textured microstructure in the presence of crystallographic slip is studied.

Cyclic Stress-strain Hardening Model of AC4C-T6 Alloy at Cryogenic Temperature (극저온 상태에서 AC4C-T6 의 가공 경화 모델 결정에 관한 연구)

  • Lee, Jae-Beom;Kim, Kyung-Su;Lee, Jang-Hyun;Yoo, Mi-Ji;Choung, Joon-Mo
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.46 no.5
    • /
    • pp.498-509
    • /
    • 2009
  • Present study is concerned with the simulation of plasticity models for the cyclic stressstrain behavior of aluminum alloy AC4C-T6 that can be used for primary materials of LNG cargo pump. Material model of cyclic hardening and plasticity for aluminum alloy AC4C-T6 was investigated through experiments and numerical simulations. Monotonic tensile and cyclic tension-compression test under symmetric load cycles was performed at both room temperature and cryogenic temperature of $-165^{\circ}C$. Based on the experimental data plastic hardening models were evaluated for isotropic/kinematic/combined hardening. FEA (Finite Element Analysis) models which describe the cyclic stress-strain relationship were evaluated for the simulation of plasticity. An appropriate hardening model is proposed comparing the results of FEA with those of experiments.

A Study on Generalization of Cyclic Plasticity Model and Application of 3-Dimensional Elastic-Plastic FEM of SM570 (SM570강재의 반복소성모델의 정식화 및 3차원 탄소성 유한요소적용에 관한 연구)

  • 장경호;장갑철;이은택
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.8 no.1
    • /
    • pp.59-65
    • /
    • 2004
  • Recently, as steel structures become higher and more long-spanned, application of high strength steel. SM570, is considered, For accurate seismic design, seismic analysis of steel structures needs a constitutive equation describing the characteristic of steel materials under non-proportional cyclic loading, While the use of SM570 material is much increased these days, research for description and generalization of cyclic plasticity behavior are insufficient, In this study, a cyclic plasticity model is proposed by results of material tests, i.e, monotonic and low cycle tests, Proposed cyclic plasticity model is applied to 3-Dimensional FE program and we carried out seismic analysis of pipe-section steel pier using SM570, Comparison between experiment and analysis results shows that the proposed constitutive equation is able to describe exactly the complicated plastic behavior of steel structure using SM570.

A Study on the Nucleation of Fretting Fatigue Cracks at the Heterogeneity Material (이종재료에서 프레팅 피로 균열의 생성에 관한 연구)

  • Goh Jun Bin;Goh Chung Hyun;Lee Kee Seok
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.14 no.3
    • /
    • pp.103-109
    • /
    • 2005
  • Since fretting fatigue damage accumulation occurs over relatively small volumes, the role of the microstructure is quite significant in fretting fatigue analysis. The heterogeneity of discrete grains and their crystallographic orientation can be accounted for using continuum crystallographic cyclic plasticity models. Such a constitutive law used in parametric studies of contact conditions may ultimately result in more thorough understanding of realistic fretting fatigue processes. The primary focus of this study is to explore the influence of microstructure as well as the magnitude of the normal force and tangential force amplitude during the fretting fatigue process. Fretting maps representing cyclic plastic strain behaviors are also developed to shed light on the cyclic deformation mechanisms.

A Rate Dependent Plasticity Model under Cyclic Loading of Metals (주기하중을 받고 있는 금속의 시간의존적 소성 모델 비교)

  • Kim, Dongkeon;Dargush, Gary F.
    • Journal of the Korean Society for Advanced Composite Structures
    • /
    • v.4 no.1
    • /
    • pp.25-32
    • /
    • 2013
  • In real world applications, the response of structures may be dependent on the rate of loading and thus can be affected by transient loading, especially when the rate of loading is significant. In such situations, the rate of loading may become a major issue to understand structures during earthquake excitation or under blast or high velocity impact. In some cases, the rate effect on structures under strong earthquake excitation cannot be ignored when attempting to understand inelastic behavior of structures. Many researchers developed the constitutive theories in cyclic plasticity and viscoplasticity. In this study, numerical simulation by cyclic visocoplasticity models is introduced and analyzed. Finally, the analytical results are compared with experimental results as a means to evaluate and verify the model.

An Estimating Method for Post-cyclic Strength and Stiffness of Eine-grained Soils in Direct Simple Shear Tests (직접단순전단시험을 이용한 동적이력 후 세립토의 강도 및 강성 예측법)

  • Song, Byung-Woong;Yasuhara, KaBuya;Murakami, Satoshi
    • Journal of the Korean Geotechnical Society
    • /
    • v.20 no.2
    • /
    • pp.15-26
    • /
    • 2004
  • Based on an estimating method for post-cyclic strength and stiffness with cyclic triaxial tests proposed by one of the authors, cyclic Direct Simple Shear (DSS) tests were carried out to confirm whether the method can be adapted to DSS test on fine-grained soils: silty clay, plastic silt, and non-plastic silt. Results from cyclic and post-cyclic DSS tests were interpreted by a modified method as adopted for cyclic and post-cyclic triaxial tests. In particular, influence of plasticity index for fine-grained soils and initial static shear stress (ISSS) was emphasised. Findings obtained from the present study are: (i) liquefaction strength ratio of fine-grained soils decreases with decreasing plasticity index and increasing ISSS; (ii) plasticity index and ISSS did not markedly influence relation between equivalent cyclic stiffness and shear strain relations; (iii) the higher the plasticity index of fine-grained soils is, the less the strength ratio decreases with increment of a normalcies excess pore water pressure (NEPWP); (iv) stiffness ratio of plastic silt has large activity decrease rapidly with increasing excess pore water pressure; and (v) post-cyclic strength and stiffness results from DSS tests agree well with those predicted by the method modified from a procedure used for triaxial test results.

Formulation of Dynamic Cyclic Plasticity Model for SM490 and Its Application to 3-Dimensional Elastic-Plastic Finite Element Analysis (SM490강재의 동적반복소성모델의 정식화 및 3차원 탄소성 유한요소해석의 적용)

  • Chang, Kyong Ho;Jang, Gab Chul
    • Journal of The Korean Society of Civil Engineers
    • /
    • v.26 no.3A
    • /
    • pp.465-471
    • /
    • 2006
  • To describe hysteretic behavior of steel structures under dynamic loading such as earthquake, the dynamic cyclic plasticity model considering stress-strain relationship and characteristics of used steel materials under static-dynamic deforming is required. In this paper, mechanical characteristics and stress-strain relationship of SM490 was clarified by carrying out static-dynamic monotonic and cyclic loading test. A dynamic cyclic plasticity model of SM490 was proposed based on the test results and applied 3-dimensional finite element analysis using finite deformation theory. An analytical method developed by the authors was verified validity and accuracy by comparing both analysis and test results. The comparison result shows that the analytical method developed by the authors can predict static-dynamic hysteretic behavior of steel structures with accuracy.

  • PDF