Implementing deformation, damage, and failure in an orthotropic plastic material model

2019 ◽  
Vol 54 (4) ◽  
pp. 463-484 ◽  
Author(s):  
Loukham Shyamsunder ◽  
Bilal Khaled ◽  
Subramaniam D Rajan ◽  
Robert K Goldberg ◽  
Kelly S Carney ◽  
...  
Keyword(s):  
Failure Criterion ◽  
High Speed ◽  
Plastic Material ◽  
Material Model ◽  
Test Results ◽  
Damage And Failure ◽  
High Speed Impact ◽  
Failure Predictions ◽  
Validation Tests ◽  
Huge Challenge

Theoretical and implementation details of an orthotropic plasticity model are presented. The model is comprised of three sub-models dealing with elastic and inelastic deformations, damage, and failure. The input to the three sub-models involves tabulated data that can be obtained from laboratory and/or virtual testing. In this article, the focus is on the development of the failure sub-model and its links to the other components. Details of how the user-selected failure criterion is used, and what steps are implemented post-failure are presented. The well-known Puck failure criterion is used in the numerical examples. Three validation tests are used to illustrate the strengths and weaknesses of the failure sub-model—10°, 15°, and 30° off-axis tests, a stacked-ply test carried out at room temperature under quasi-static loading, and finally, a high-speed impact test. Results indicate that while the deformation and damage sub-models give reasonably accurate results, the failure predictions are a huge challenge especially for high-speed impact tests.

Experimental characterization of composites to support an orthotropic plasticity material model

2017 ◽  
Vol 52 (14) ◽  
pp. 1847-1872 ◽  
Author(s):  
Bilal Khaled ◽  
Loukham Shyamsunder ◽  
Canio Hoffarth ◽  
Subramaniam D Rajan ◽  
Robert K Goldberg ◽  
...  
Keyword(s):  
Material Model ◽  
Unidirectional Composite ◽  
Deformation Model ◽  
Test Results ◽  
Dynamic Impact ◽  
Test Procedures ◽  
Stress Strain ◽  
Damage And Failure ◽  
Orthotropic Behavior

Test procedures for characterizing the orthotropic behavior of a unidirectional composite at room temperature and quasi-static loading conditions are developed and discussed. The resulting data consisting of 12 stress–strain curves and associated material parameters are used in a newly developed material model—an orthotropic elasto-plastic constitutive model that is driven by tabulated stress–strain curves and other material properties that allow for the elastic and inelastic deformation model to be combined with damage and failure models. A unidirectional composite—T800/F3900, commonly used in the aerospace industry, is used to illustrate how the experimental procedures are developed and used. The generated data are then used to model a dynamic impact test. Results show that the developed framework implemented into a special version of LS-DYNA yields reasonably accurate predictions of the structural behavior.

Integrated Dynamic Thermo-Mechanical Modeling of High Speed Spindles, Part 2: Solution Procedure and Validations

2004 ◽  
Vol 126 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Hongqi Li ◽  
Yung C. Shin
Keyword(s):  
High Speed ◽  
Solution Procedure ◽  
Operating Conditions ◽  
Test Results ◽  
Mechanical Modeling ◽  
Spindle Bearing ◽  
Wide Range ◽  
Bearing Stiffness ◽  
Models Validation ◽  
Validation Tests

This paper presents a new solution procedure for an integrated thermo-dynamic spindle model and validation results. Based on the model presented in Part 1 of this paper, a computer program has been developed to generate comprehensive solutions for high speed spindle-bearing systems, such as bearing stiffness, contact load and temperature, spindle dynamic characteristics and response, temperature distributions, and thermal expansions. The model and the solution procedure are modular such that solutions for different spindle set-ups can be easily generated by combining a given spindle model with different toolholder models. Validation test results for thermal and dynamic predictions are presented for four different spindle systems, including the thermal and dynamic validation tests on a specially constructed spindle testbed. The validation results show the model has accurate predictive capabilities for a wide range of operating conditions and various spindle designs.

An Efficient Numerical Method for Dynamic Interaction Analysis of Shinkansen Train and Railway Structure During an Earthquake

2007 ◽  
Author(s):  
M. Tanabe ◽  
N. Matsumoto ◽  
H. Wakui ◽  
M. Sogabe ◽  
H. Okuda ◽  
...  
Keyword(s):  
Numerical Method ◽  
High Speed ◽  
Large Scale ◽  
Interaction Analysis ◽  
Plastic Material ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Material Model ◽  
Dynamic Interaction ◽  
Contact Dynamics

In this paper, a simple and efficient numerical method to solve for the dynamic interaction of a Shinkansen train (high-speed train in Japan) and railway structure during an earthquake is given. The motion of the train is modeled in multibody dynamics with nonlinear springs and dampers used to connect components. An efficient mechanical model for contact dynamics between wheel and rail during an earthquake is presented. The railway structure is modeled with various finite elements. A three-dimensional nonlinear spring element based on a trilinear elastic-plastic material model is given for the concrete railway structure during an earthquake. A loop structure model has been devised to obtain an approximated combined motion of the train and railway structure during an earthquake. A modal method has been developed to solve large-scale nonlinear equations of motion of the train and railway structure effectively. Based on the present method, a computer program DIASTARS for the dynamic interaction of a Shinkansen train and railway structure during an earthquake has been developed. Numerical examples are demonstrated.

Computational Model for a High Speed Train Running on the Railway Structure Including Derailment during an Earthquake

2012 ◽  
Vol 579 ◽  
pp. 473-482 ◽  
Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Masamichi Sogabe ◽  
Nobuyuki Matsumoto ◽  
Keiichi Gotou ◽  
...  
Keyword(s):  
Multibody Dynamics ◽  
High Speed ◽  
Plastic Material ◽  
Kinematic Hardening ◽  
Time Integration ◽  
Material Model ◽  
Small Time ◽  
Computational Method ◽  
Integration Scheme ◽  
High Speed Train

The computational method to solve for the dynamic interaction between a high-speed train and the railway structure including derailment during an earthquake is given. The motion of the train is expressed in multibody dynamics. Efficient mechanical models to express contact-impact behaviors between wheel and the track structure including derailment during an earthquake are given. Rail and track elements with multibody dynamics and FEM combined have been developed. A nonlinear spring element based on a trilinear elastic-plastic material model with the kinematic hardening is given for a concrete railway structure under cyclic loads during an earthquake. The motion of a railway structure is modeled with various finite elements and also with rail and track elements. A modal reduction is applied to solve the problem effectively. An exact time integration scheme has been developed that is free from the round-off error for very small time increments needed to solve the interaction between wheel and railway structure including derailment during an earthquake. Numerical examples are demonstrated.

High Speed Impact Characteristics of Plastic Material Based on Finite Element Simulation

2011 ◽  
Vol 383-390 ◽  
pp. 3229-3233 ◽  
Author(s):  
Waluyo Adi Siswanto ◽  
Rodzilla Y. Sharafuddin ◽  
Perowansa Paruka
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Plastic Material ◽  
Strain History ◽  
Finite Element Program ◽  
High Speed Impact ◽  
Element Simulation ◽  
Material Specimen ◽  
Element Program ◽  
As Stress

Testing material specimen on impact using high speed puncture machine can be used to observe the ability of material to withstand under a certain impact speed by looking at the energy required to tear the material. Other detail parameters such as stress, strain and tearing development on impact cannot be seen or measured. This paper presents a finite element method approach to see the strain history and the tearing sequence that cannot be obtained during impact puncture testing of plastic material (Polyethylene Terephthalate / PET). Simulations in different speed; 10 m/s (36 km/h) and 20 m/s (72 km/h) are performed employing a dynamic-explicit Impact finite element program suite. The simulations are able to capture the tearing process, to see the strain histories of tearing region and to predict the tearing pattern. The tearing pattern simulation results are verified by comparing with that from experiment.

Improving failure sub-models in an orthotropic plasticity-based material model

2020 ◽  
pp. 002199832098265
Author(s):  
Loukham Shyamsunder ◽  
Bilal Khaled ◽  
Subramaniam D Rajan ◽  
Gunther Blankenhorn
Keyword(s):  
Finite Element ◽  
Failure Criterion ◽  
High Speed ◽  
Simulation Models ◽  
Material Model ◽  
Failure Criteria ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
Static Tensile

Theoretical details of two failure criteria implemented in an orthotropic plasticity model are presented. Improvements to the well-known Puck Failure criterion and a recently developed Generalized Tabulated Failure criterion are used to illustrate how to link a failure sub-model to existing deformation and damage sub-models in the context of explicit finite element analysis. These models are implemented in LS-DYNA, a commercial transient dynamic finite element code. Two validation tests are used to evaluate the failure sub-model implementation and improvements - a stacked-ply test carried out at room temperature under quasi-static tensile and compressive loadings, and a high-speed, projectile impact test where there is significant damage and material failure of the impacted panel. Results indicate that developed procedures and improvements provide the analyst with a reasonable and systematic approach to building predictive impact simulation models.

Study of Material Modeling of Polymers for Impact Analysis

2014 ◽  
Vol 566 ◽  
pp. 474-479 ◽  
Author(s):  
Kunio Takekoshi ◽  
Kazukuni Niwa
Keyword(s):  
Tensile Test ◽  
High Speed ◽  
Impact Analysis ◽  
Material Model ◽  
Tensile Tests ◽  
Material Modeling ◽  
Test Results ◽  
Charpy Test ◽  
Rate Dependent ◽  
Dog Bone

High-speed tensile tests were carried out to investigate strain rate effect on both yield stress and failure strain using ASTM D1822 Type-S specimens made of polycarbonate. Based on test results, parameters for a material model suitable for polymers are determined, and numerical analysis is carried out to simulate test results. The material model is used to simulate tensile test using a dog-bone specimen and Charpy test other than the tensile test of Type-S specimens. It is found that good predictions can be obtained when rate dependent material parameters are used. Further, the high-speed tensile test considered in the present study is suitable for selection of parameters for material modeling of polymers for impact analysis.

scholarly journals Framework for Predicting Failure in Polymeric Unidirectional Composites through Combined Experimental and Computational Mesoscale Modeling Techniques

Fibers ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 50
Author(s):  
Bilal Khaled ◽  
Loukham Shyamsunder ◽  
Josh Robbins ◽  
Yatin Parakhiya ◽  
Subramaniam D. Rajan
Keyword(s):  
Experimental Data ◽  
Principal Direction ◽  
Material Model ◽  
Unidirectional Composite ◽  
Modeling Framework ◽  
Deformation And Failure ◽  
Damage And Failure ◽  
Unit Cells ◽  
Failure Predictions ◽  
Composite Response

As composites continue to be increasingly used, finite element material models that homogenize the composite response become the only logical choice as not only modeling the entire composite microstructure is computationally expensive but obtaining the entire suite of experimental data to characterize deformation and failure may not be possible. The focus of this paper is the development of a modeling framework where plasticity, damage, and failure-related experimental data are obtained for each composite constituent. Mesoscale finite elements models consisting of multiple repeating unit cells are then generated and used to represent a typical carbon fiber/epoxy resin unidirectional composite to generate the complete principal direction stress-strain curves. These models are subjected to various uniaxial states of stress and compared with experimental data. They demonstrate a reasonable match and provide the basic framework to completely define the composite homogenized material model that can be used as a vehicle for failure predictions.

scholarly journals Numerical studies of cavitation erosion on an elastic–plastic material caused by shock-induced bubble collapse

2017 ◽  
Vol 473 (2205) ◽  
pp. 20170315 ◽  
Author(s):  
C. K. Turangan ◽  
G. J. Ball ◽  
A. R. Jamaluddin ◽  
T. G. Leighton
Keyword(s):  
High Speed ◽  
Plastic Material ◽  
Material Model ◽  
Solid Surfaces ◽  
Bubble Collapse ◽  
Liquid Jets ◽  
Elastic Plastic ◽  
Numerical Studies ◽  
Elastic Plastic Material ◽  
Bubble Sizes

We present a study of shock-induced collapse of single bubbles near/attached to an elastic–plastic solid using the free-Lagrange method, which forms the latest part of our shock-induced collapse studies. We simulated the collapse of 40 μm radius single bubbles near/attached to rigid and aluminium walls by a 60 MPa lithotripter shock for various scenarios based on bubble–wall separations, and the collapse of a 255 μm radius bubble attached to aluminium foil with a 65 MPa lithotripter shock. The coupling of the multi-phases, compressibility, axisymmetric geometry and elastic–plastic material model within a single solver has enabled us to examine the impingement of high-speed liquid jets from the shock-induced collapsing bubbles, which imposes an extreme compression in the aluminium that leads to pitting and plastic deformation. For certain scenarios, instead of the high-speed jet, a radially inwards flow along the aluminium surface contracts the bubble to produce a ‘mushroom shape’. This work provides methods for quantifying which parameters (e.g. bubble sizes and separations from the solid) might promote or inhibit erosion on solid surfaces.

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