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A user-defined subroutine for numerical modelling of failure due to creep under compression in carbon fibre reinforced composite materials

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MATERIALS RESEARCH EXPRESS 2019年第8期6卷

作者： Jamil, Azhar Varshney, Vimal Aligarh Muslim Univ Dept Mech Engn Aligarh Uttar Pradesh India

Creep is one of the prominent failures of industrial components particularly under continuous loading conditions, elevated temperatures and material diversities etc. In this work, a user defined *CREEP subroutine has been developed and implemented in the commercial finite element code of ABAQUS (R), employing the time hardening formulation of Norton-Bailey power law, to numerically simulate the failure due to creep under compression, in carbon fibre reinforced plastic CFRP composites. As such a circular stacked carbon fibre disc CSCFD has been taken from the works of Scattina et al 2015 Compos. Struct. 134, 378-383. Along with creep behaviour data, corresponding to 30 MPa, 40 MPa and 50 MPa loads, from which time-hardening formulation of Norton-Bailey law was formulated. Sensitivity analyses were performed on the parameters of this time-hardening formulation, revealing the optimised parameters corresponding to the composite material. These parameters were implemented in ABAQUS (R) for the simulation of creep which revealed time interval discrepancy between the *STATIC and *VISCO steps. This led to the development of a user-defined *CREEP subroutine along with orthotropic material formulations which successfully incorporated this discrepancy. The results, so obtained from the subroutine, are in excellent agreement with the reported experimental data in Scattina et al 2015 Compos. Struct. 134, 378-383, thus validating the numerical model and the developed subroutine making it possible to understand the creep behaviour in these materials.

关键词： Creep time hardening bailey-norton law user-defined subroutine

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Investigation of acoustic-plastic constitutive modeling based on Johnson-Cook model and numerical simulation application

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ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING 2021年第2期21卷 77页

作者： Wang, Xingxing Qi, Zhenchao Chen, Wenliang Nanjing Univ Aeronaut & Astronaut Coll Mech & Elect Engn Nanjing 210016 Peoples R China

In this paper, a modified acoustic-plastic Johnson-Cook model for Ti-45Nb alloy was established, which can be used to reveal the metallic deformation behavior under ultrasonic vibration-assisted (TUV) forming. First, the experiments of traditional compression and TUV compression were carried out, the influence of vibration amplitude on yield strength, strain hardening coefficient and index, and strain rate hardening coefficient. The yield strength reduction is caused by the acoustic softening effect. The yield strength and strain hardening coefficient present a negative correlation with amplitude increase, the strain hardening index and strain rate hardening coefficient present a positive correlation with amplitude increase. Further, the accuracy of the developed constitutive model was quantitatively identified, the relative coefficient is as high as 0.954, the mean absolute percentage error less than 5.42%. On this basis, a user-defined subroutine was developed to implement the numerical simulation of the TUV forming processes using the finite element method, the results of numerical simulation and experiment are in good agreement, and prediction accuracy is as high as 95.25%. Therefore, the developed constitutive model can be well revealed the material deformation behavior and provides an application guide.

关键词： Transversal ultrasonic vibration Johnson– Cook model Numerical simulation user-defined subroutine Forming process

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Double Strength Reduction Method for Slope Stability Analysis Based on Water Content Variation: A Study and Engineering Application

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WATER 2023年第6期15卷 1194-1194页

作者： Liu, Xiaoliang Su, Mei China Univ Min & Technol Beijing State Key Lab Geomech & Deep Underground Engn Beijing 100083 Peoples R China China Univ Min & Technol Beijing Sch Mech & Civil Engn Beijing 100083 Peoples R China Liupanshui Normal Univ Sch Min & Mech Engn Liupanshui 553000 Peoples R China

Soil moisture content changes caused by rainfall and other factors can significantly affect slope stability and potentially lead to geological disasters, such as landslides and debris flows. However, conventional finite element methods for strength reduction do not consider the impact of water content on slope stability. This paper examines classical finite element methods for reducing the double strength coefficient and then introduces a novel approach using changes in moisture content. The new method is implemented through the use of an ABAQUS FE program's USDFLD user-defined subroutine. This paper concludes by contrasting the outcomes derived from the limit equilibrium technique and other techniques and verifying the accuracy of the suggested approach through theoretical and numerical simulations. The numerical calculations for the stability evaluation of the Azhuoluo slope in the Chinese province of Guizhou, Shuicheng county were performed utilizing the ABAQUS FE platform's USDFLD user-defined subroutine based on the double-strength discounting method, in response to the large landslide disaster in the region. The results show that the red clay, formed from the weathering of basalt in the area, experiences asynchronous decay in both friction angle and cohesion as the water content increases, with a significantly higher decay rate in the internal friction angle compared to cohesion. This indicates that traditional finite element methods that synchronously discount the internal friction angle and cohesion do not correspond to reality, whereas this proposed double-strength discounting method, based on water content changes, accurately reflects the essential characteristics of slope instability and has clear physical meaning and practical engineering applications.

关键词： double strength reduction weathered-basalt soil soil water content user-defined subroutine landslides

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Three-Dimensional Nonlinear Finite Element Modeling for Bond Performance of Ribbed Steel Bars in Concrete Under Lateral Tensions

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INTERNATIONAL JOURNAL OF CIVIL ENGINEERING 2020年第5A期18卷 595-617页

作者： Jiang, Tao Wu, Zhimin Huang, Le Ye, Hailong Dalian Univ Technol Lab Coastal & Offshore Engn 2 Linggong Rd Dalian Liaoning Peoples R China Univ Hong Kong Dept Civil Engn Pokfulam Hong Kong Peoples R China

Development of experimental studies in bond behavior between deformed bar and concrete under complex stress conditions in the last 2 decades is significantly affecting the concrete design specification. This article presents a rib-scale finite element model (FEM) to study the bond behavior of deformed bar in concrete under lateral tensions. In this model, detailed modeling including the reinforcing bar ribs and the concrete keys in contact region is realized with real geometric parameters. At the concrete-bar interface, surface-to-surface contacts with tie constraints are used and relative sliding or separation between contact surfaces are inhibited;adhesion between concrete and deformed bar is ignored. A user-defined subroutine named VUSDFLD in ABAQUS software was incorporated into the concrete damaged plasticity (CDP) model to acquire more accurate concrete constitutive relations. The FEM is calibrated using pullout test data from published papers. The simulation results show that all specimens failed in splitting mode. The lateral tension is an adverse factor on the bond property between steel bar and concrete, both the ultimate bond strength and the slip at the peak bond stress decrease with the increase of the lateral tensions. Comparison of computational simulation with the experimental data indicates that the proposed model gives a reasonable prediction of the bond stress-slip curves as well as the concrete crack patterns.

关键词： Nonlinear finite element modeling Ribbed reinforcing bar Concrete user-defined subroutine Bond stress-slip relationship Lateral tensions

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The structural response of the thermoplastic composite joint subjected to out-of-plane loading

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INTERNATIONAL JOURNAL OF IMPACT ENGINEERING 2020年 145卷 103691-103691页

作者： Chen, Chao Sun, Changze Han, Xu Hu, Dean Zhou, Jin Guan, Zhongwei Hunan Univ State Key Lab Adv Design & Mfg Vehicle Body Changsha 410082 Peoples R China Univ Liverpool Sch Engn Liverpool L69 3GH Merseyside England Hebei Univ Technol Sch Mech Engn Tianjin 300401 Peoples R China Xi An Jiao Tong Univ Sch Mech Engn Xian 710049 Peoples R China Chengdu Univ Sch Mech Engn Chengdu 610106 Peoples R China

This paper presents a study on thermoplastic single-lap double rivet joints (SLDJ) with and without adhesive subjected to out-of-plane projectile impact and quasi-static concentrated loading. The three-dimensional finite element (FE) models considering strain-rate effects and damage evolution were developed and implemented in the commercial code Abaqus/Explicit through a user-defined subroutine VUMAT. The FE models were validated against the experimental results, in terms of the peak load, the maximum displacement and the dissipated energy. It was found that there were three stages in the load-displacement trace up to the failure, i.e. rivet slip, hole failure and laminate break for the rivet joint, and debonding, rivet slip and laminate break for the rivet joint with adhesive. The rivet joint with adhesive has a higher stiffness before debonding occurs;however, its out-of plane load carrying capacity is slightly lower than the rivet only counterpart. The validated models were used to study the failure mechanisms of SLDJ through the progressive failure simulation, and further to investigate the effects of boundary conditions, ply angle and impact energy on the impact response of the composite joints. The laminates with 45 degrees ply could be used to enhance the impact resistance of composite joint structures with the reduced damaged area.

关键词： Thermoplastic composite joint Out-of-plane impact Finite element user-defined subroutine

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Dynamic Stress Analysis on Barrel Considering the Radial Effect of Propellant Gas Flow

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JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME 2019年第1期141卷 011202-011202页

作者： Yu, Qingbo Yang, Guolai Nanjing Univ Sci & Technol Sch Mech Engn Nanjing 210094 Jiangsu Peoples R China

The stress response of an artillery barrel when fired is principally due to loading from gas pressure and contact force with the projectile. This paper reports a research project in which a dynamic model of a barrel and a projectile was established in order to investigate the stress response of an artillery barrel. Calculations of propellant gas pressure, in part determined by the position of the moving projectile, were carried out using user-defined subroutines developed in the ABAQUS/EXPLICIT software. Numerical simulations of the dynamic loading process of the barrel were carried out to examine the radial effects of gas pressures. Using this methodology, the evolution of barrel stress distributions was simulated, providing a visualized representation of the barrel's dynamic response. The calculated dynamic stress due to projectile contact alone can reach a peak value of 181 MPa, reflecting the significant effect of contact force on the barrel's dynamic response. Following this, the effect of propellant combustion on the dynamic response was explored, and the results obtained showed that higher initial temperatures produced more pronounced dynamic responses. Moreover, significant differences in stress distributions computed for the barrel revealed deficiencies in the static strength theory for evaluating the operating conditions, due in part to the omission of contact force and other dynamic effects. This paper proposes an alternative investigative approach for evaluating the dynamic stress response of barrels during the initial phases of the ballistics process, and provides information that should lead to updates and improvements of barrel strength theory, ultimately leading to better predictions of firing reliability and operator safety.

关键词： barrel stress response projectile-barrel coupled model radial effect of gas pressure ABAQUS/EXPLICIT user-defined subroutine

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Stress analysis and damage evolution in individual plies of notched composite laminates subjected to in-plane loads

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Chinese Journal of Aeronautics 2017年第1期30卷 447-460页

作者： Hu Junshan Zhang Kaifu Cheng Hui Liu Ping Zou Peng Song Danlong The Ministry of Education Key Lab of Contemporary Design and Integrated Manufacturing Technology Northwestern Polytechnical University Xi'an 710072 China School of Mechanical Engineering Northwestern Polytechnical University Xi'an 710072 China

This work aims to investigate local stress distribution, damage evolution and failure of notched composite laminates under in-plane loads. An analytic method containing uniformed boundary equations using a complex variable approach is developed to present layer-by-layer stresses around the notch. The uniformed boundary equations established in series together with conformal mapping functions are capable of dealing with irregular boundary issues around the notch and at infinity. Stress results are employed to evaluate the damage initiation and propagation of notched composites by progressive damage analysis（PDA）. A user-defined subroutine is developed in the finite element（FE） model based on coupling theories for mixed failure criteria and damage mechanics to efficiently investigate damage evolution as well as failure modes. Carbon/epoxy laminates with a stacking sequence of [45°/0°/ 60°/90°]sare used to investigate surface strains, in-plane load capacity and microstructure of failure zones to provide analytic and FE methods with strong validation. Good agreement is observed between the analytic method, the FE model and experiments in terms of the stress（strain） distributions, damage evaluation and ultimate strength, and the layerby-layer stress components vary according to a combination effect of fiber orientation and loading type, causing diverse failure modes in individuals.

关键词： Damage evolution Failure mode Failure strength Layer-by-layer stresses user-defined subroutine

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A New Multi-Body Dynamic Model of a Deep Ocean Mining Vehicle-Pipeline-Ship System and Simulation of Its Integrated Motion

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STROJNISKI VESTNIK-JOURNAL OF MECHANICAL ENGINEERING 2016年第12期62卷 757-763页

作者： Dai, Yu Pang, Liping Chen, Lisong Zhu, Xiang Zhang, Tao Cent S Univ Coll Mech & Elect Engn Changsha 410083 Hunan Peoples R China Shanghai Jiao Tong Univ State Key Lab Ocean Engn Shanghai 200030 Peoples R China Cent S Univ Shenzhen Res Inst Changsha Hunan Peoples R China

In this paper, a three-dimensional multi-body dynamic model of a seafloor mining vehicle is developed in the RecurDyn simulation program by integrating the developed terramechanics model of the seafloor sediment. The discrete element method (DEM) is employed to model a mining pipeline as discrete rigid elements linked by flexible connectors. An innovative user-defined subroutine for parametrically and rapidly automatically building a DEM model for such long pipeline is developed in the C# language in RecurDyn. A new 3D multi-body dynamic mode/ of a total deep ocean mining vehicle-pipeline-ship system is established with the integration of developed models for subsystems. The integrated motion simulations are achieved and demonstrate that the synchronized stable motion of the total system can be well maintained during operation processes.

关键词： deep ocean mining system terramechanics model multi-body dynamic model discrete element model user-defined subroutine integrated motion simulation

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Numerical model to predict deformation of corrugated austenitic stainless steel sheet under cryogenic temperatures for design of liquefied natural gas insulation system

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MATERIALS & DESIGN 2014年 57卷 26-39页

作者： Kim, Jeong-Hyeon Kim, Seul-Kee Kim, Myung-Hyun Lee, Jae-Myung Pusan Natl Univ Dept Naval Architecture & Ocean Engn Pusan 609735 South Korea

Austenitic stainless steel exhibits nonlinear hardening behavior at low temperature and under various strain rate conditions caused by the phenomenon of transformation-induced plasticity (TRIP). In this study, a uniaxial tensile test for 304L austenitic stainless steel was performed below ambient temperature (-163, -140, -120, -50, and 20 degrees C) and at strain rates (10 (4), 10 (3), and 10 (2) s (1)) to identify nonlinear mechanical characteristics. In addition, a viscoplastic damage model was proposed and implemented in a user-defined material subroutine to provide a theoretical explanation of the nonlinear hardening features. The verification was conducted not only by a material-based comparative study involving experimental investigations, but also by a structural application to the corrugated steel membrane of a Mark-III-type cargo containment system for liquefied natural gas. In addition, an accumulated damage contour was represented to predict the failure location by using a continuum damage mechanics approach. (2013) Elsevier Ltd. All rights reserved.

关键词： 304L stainless steel Transformation-induced plasticity Corrugated steel membrane Liquefied natural gas insulation system user-defined subroutine

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Two Novel Adams Model Encapsulation Methods in HLA Based Collaborative Product Development

Two Novel Adams Model Encapsulation Methods in HLA Based Col...

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3rd International Conference on Mechanical and Electronics Engineering (ICMEE 2011)

作者： Ma, Cheng Xiao, Tianyuan Fan, Wenhui Sun, Hongbo Yue, Yingchao Tsinghua Univ Natl CIMS ERC Beijing 100084 Peoples R China

ISBN: (纸本)9783037852866

As a well-known standard of distributed simulation, High Level Architecture (H LA) has adopted as basic framework in most distributed interactive simulation (DIS) systems. At the same time, DIS always involves multiple disciplinary simulation models which are supported by different software. And these software are not always compatible with HLA. For example, though widely used in mechanical kinetics and kinematics simulations, ADAMS, a multi-body kinetics simulation software cannot directly support HLA. To address this issue, this paper analyses redevelopment of legacy systems and models (such as Adams models) in DIS environment and proposes two encapsulation methods which is based on third-party software and user-defined subroutines respectively. A case study demonstrates the feasibility of the proposed methods. And a brief comparison is also given in conclusion section.

关键词： HLA DIS Model Encapsulation ADAMS user-defined subroutine

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