A nonlinear strain rate and pressure-dependent micro-mechanical composite material model for impact problems

2017 ◽  
Vol 31 (12) ◽  
pp. 1634-1660 ◽  
Author(s):  
Sandeep Medikonda ◽  
Ala Tabiei
Keyword(s):  
Composite Material ◽  
Strain Rate ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Material Model ◽  
Distribution Functions ◽  
Failure Behavior ◽  
Nonlinear Strain ◽  
Impact Problems ◽  
The Impact

A micro-mechanical composite material model is developed to simulate the behavior of unidirectional composites under impact loading conditions in the nonlinear finite element solver (LS-DYNA®). The nonlinear strain rate and pressure dependency in the composite material model is accounted by the resin, which uses previously developed state variable viscoplastic equations. These equations have been originally developed for metals; however, these are modified to account for the significant contributions of hydrostatic stresses typically observed in polymers. The material model also uses a continuum damage mechanics (CDM) based failure model to incorporate the progressive post-failure behavior. A set of Weibull distribution functions are used to quantify this behavior, and a methodology of assigning physical significance to the choice of damage/softening parameters used in these functions is presented. The impact response of composite laminate plates has been simulated and compared to the experiments. It has been observed that the predicted results compare favorably to the experiments.

Fracture in Taylor Rod Impact Test Specimens

2010 ◽  
Author(s):  
Sachin S. Gautam ◽  
Ravindra K. Saxena ◽  
P. M. Dixit
Keyword(s):  
Ductile Fracture ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Outer Edge ◽  
Impact Surface ◽  
Mechanics Model ◽  
Contact Impact ◽  
Impact Problems ◽  
The Impact ◽  
Aisi1045 Steel

High velocity contact-impact problems are of great interest in industries related to aerospace, mechanical and civil engineering. Ductile fracture often occurs in such applications. Taylor rod impact tests are used as experimental and numerical tests for determining the mechanical behaviour of materials subjected to high strain rates. At sufficiently high velocities, a significant plastic deformation leading to fracture is observed. In this paper, ductile fracture in Taylor rod made of AISI1045 steel is simulated using a continuum damage mechanics model. Simulations are performed for the velocity of 250 and 300 m/s. It is observed that, at lower velocities, tensile cracks are observed at the outer edge of the impact surface. On the other hand, at higher velocities, the fracture is observed at the central axis (confined fracture) as well as at the outer edge leading to fragmentation. Both the results are consistent with the experimental results available in the literature.

Continuum damage mechanics-based analysis of creep–fatigue interaction behavior in a turbine rotor

2018 ◽  
Vol 28 (3) ◽  
pp. 455-477 ◽  
Author(s):  
WZ Wang ◽  
YZ Liu
Keyword(s):  
Damage Mechanics ◽  
Maximum Stress ◽  
Continuum Damage Mechanics ◽  
Turbine Rotor ◽  
Von Mises Stress ◽  
Temperature Phase ◽  
Continuum Damage ◽  
Interaction Behavior ◽  
Creep Fatigue ◽  
The Impact

The aim of this study is to analyze the creep–fatigue interaction behavior of a steam turbine rotor under idealized cyclic thermomechanical loading conditions. A Chaboche model-based material constitutive model is applied to simulate the multiaxial stress–strain behavior in the rotor. Influence of accumulated damage during the whole iterations on the creep–fatigue interaction behavior is described by continuum damage mechanics. Analysis of the temperature and stress variations during the startup phase reveals that the startup phase can be divided into a condensation phase, a high steam flux phase, and an elevated temperature phase and that thermal stress reaches its maximum value in the condensation phase. In addition, creep–fatigue interaction in the rotor leads to a gradual decrease in the maximum stress; furthermore, comparison of the von Mises stress displays that the impact of damage accumulation results in the shift of the location with the maximum stress. Investigation of creep–fatigue damage discloses that the total damage is concentrated on the steam inlet notch zone and the blade groove of the first and third stages.

scholarly journals Study of the ballistic behaviour of UHMWPE composite material: experimental characterization and numerical simulation

2018 ◽  
Vol 183 ◽  
pp. 01051
Author(s):  
Hakim Abdulhamid ◽  
Paul Deconinck ◽  
Pierre-Louis Héreil ◽  
Jérôme Mespoulet
Keyword(s):  
Numerical Simulation ◽  
Composite Material ◽  
Damage Model ◽  
Material Model ◽  
Polyethylene Composite ◽  
Macro Scale ◽  
Out Of Plane ◽  
Peeling Strength ◽  
Scale Levels ◽  
The Impact

This paper presents a comprehensive mechanical study of UHMWPE (Ultra High Molecular Weight Polyethylene) composite material under dynamic loadings. The aim of the study is to provide reliable experimental data for building and validate the composite material model under impact. Four types of characterization tests have been conducted: dynamic in-plane tension, out-of-plane compression, shear tests and plate impact tests. Then, several impacts of spherical projectiles have been performed. Regarding the numerical simulation, an intermediate scale multi-layered model (between meso and macro scale levels) is proposed. The material response is modelled with a 3d elastic orthotropic law coupled with fibre damage model. The modelling choice is governed by a balance between reliability and computing cost. Material dynamic response is unconventional [1, 2]: it shows large deformation before failure, very low shear modulus and peeling strength. Numerical simulation has been used both in the design and the analysis of tests. Many mechanical properties have been measured: elastic moduli, failure strength and EOS of the material. The numerical model is able to reproduce the main behaviours observed in the experiment. The study has highlighted the influence of temperature and fibre slipping in the impact response of the material.

A Damage Model for Adhesively Bonded Single-Lap Thick Composite Joints

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Sayed A. Nassar ◽  
Jianghui Mao ◽  
Xianjie Yang ◽  
Douglas Templeton
Keyword(s):  
Damage Mechanics ◽  
Resin Composite ◽  
Analytical Data ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Epoxy Adhesive ◽  
Failure Behavior ◽  
Adhesively Bonded ◽  
Damage Initiation ◽  
Damage Models

A proposed damage model is used for investigating the deformation and interfacial failure behavior of an adhesively bonded single-lap thick joint made of S2 glass/SC-15 epoxy resin composite material. The bonding material is 3M Scotch-Weld Epoxy Adhesive DP405 Black. Continuum damage mechanics models are used to describe the damage initiation and final failure at or near the interface. The effect of adhesive overlap length, thickness, and plasticity on the interfacial shear and normal stresses is studied. Experimental and analytical data are used to validate the proposed damage models.

Development of an Orthotropic Elasto-Plastic Generalized Composite Material Model Suitable for Impact Problems

2016 ◽  
Vol 29 (4) ◽  
pp. 04015083 ◽  
Author(s):  
Robert K. Goldberg ◽  
Kelly S. Carney ◽  
Paul DuBois ◽  
Canio Hoffarth ◽  
Joseph Harrington ◽  
...  
Keyword(s):  
Composite Material ◽  
Material Model ◽  
Impact Problems

Modeling of the Strain Rate Dependent Material Behavior of 3D-Textile Composites with Production and Operational Defects

2011 ◽  
Vol 403-408 ◽  
pp. 651-655
Author(s):  
W. Hufenbach ◽  
M. Gude ◽  
R. Protz
Keyword(s):  
Strain Rate ◽  
Damage Mechanics ◽  
Additive Model ◽  
Experimental Tests ◽  
Continuum Damage Mechanics ◽  
Textile Composites ◽  
Material Behavior ◽  
Rate Dependent ◽  
Dynamic Tensile Loading ◽  
Good Coincidence

This paper concerned with modeling of the strain rate dependent material behavior of 3D-textile composites with simultaneous consideration of production and operational (e.g. pores or fatigue damage) defects. Therefore an additive model in the sense of continuum damage mechanics was introduced. For the model validation extensive experimental tests on glass non-crimp fabrics reinforced epoxy (GF-NCF/EP) composites are performed. The focus is put on the influence of production and fatigue related pre-damage under subsequent highly-dynamic tensile loading. The theoretical studies shows a good coincidence with the experimentally results

Elastic Ply Damage Mechanics Modeling of Glass/Epoxy Laminated Composite

2013 ◽  
Vol 683 ◽  
pp. 176-181
Author(s):  
Yong Chen ◽  
Bao Jun Pang ◽  
Wei Zheng
Keyword(s):  
Composite Material ◽  
Damage Mechanics ◽  
Epoxy Composite ◽  
Damage Model ◽  
Laminated Composite ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Tensile Shear ◽  
Mechanics Model ◽  
Input Parameters

In order to establish an elastic damage model for S2-glass/epoxy composite and identify the input parameters, in-plane behaviour of the composite including tensile, compression and tensile shear were investigated through series of tests. Concerning no plasticity, a simple elastic ply damage mechanics model for this composite was characterized based on Continuum Damage Mechanics Model (CDM) and the input parameters were obtained. The model was then implemented into ABAQUS/EXPLICT and the results show the model can capture most of the in-plane behaviour of the composite material.

Development of “Material Specific” Creep Continuum Damage Mechanics-Based Constitutive Equations

2020 ◽  
Author(s):  
Ricardo Vega ◽  
Jaime A. Cano ◽  
Calvin M. Stewart
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Creep Strain ◽  
Creep Deformation ◽  
Damage Evolution ◽  
Damage Mechanics ◽  
Constitutive Models ◽  
Continuum Damage Mechanics ◽  
Creep Strain Rate ◽  
Continuum Damage

Abstract The objective of this study is to introduce a method for creating “material specific” creep continuum damage mechanics-based constitutive models. Herein, material specific is defined as a constitutive model based on the mechanism-informed minimum creep strain rate (MCSR) equations found in deformation mechanism maps and calibrated to available material data. The material specific models are created by finding the best MCSR model for a dataset. Once the best MCSR model is found, the Monkman Grant inverse relationship between the MCSR and rupture time is employed to derive a rupture equation. The equations are substituted into continuum damage mechanics-based creep strain rate and damage evolution equations to furnish predictions of creep deformation and damage. Material specific modeling allows for the derivation of creep constitutive models that can better the material behavior specific to the available data of a material. The material specific framework is also advantageous since it has a systematic framework that moves from finding the best MCSR model, to rupture time, to damage evolution and, creep strain rate. Data for Alloy P91 was evaluated and a material specific constitutive model derived. The material specific model was able to accurately predict the MCSR, creep deformation, damage, and rupture of alloy P91.

Simulation of softening in high pressure torsion process using continuum damage mechanics model

2021 ◽  
pp. 095440622110338
Author(s):  
Shubhi Katiyar ◽  
Prakash Mahadeo Dixit
Keyword(s):  
High Pressure ◽  
Damage Mechanics ◽  
High Pressure Torsion ◽  
Compressive Load ◽  
Continuum Damage Mechanics ◽  
Material Model ◽  
Work Piece ◽  
Continuum Damage ◽  
Mechanics Model ◽  
Insight Into

Severe Plastic Deformations (SPD) processes are used for grain refinement without any loss in ductility. Among various SPD processes, High Pressure Torsion (HPT) is extensively used in industries due to generation of high angle grain boundaries and cost effectiveness. Very little work has been reported on the numerical analysis of softening with recovery that might occur in a work-piece undergoing HPT. The present work is an attempt to study the softening behaviour in HPT processed mild steel and aluminium alloy using the Lemaitre’s continuum damage mechanics (CDM) model. This model is implemented in ABAQUS/Explicit through a user defined material model subroutine (VUMAT). A parametric study is carried out to study the effect on softening of various parameters like the compressive load, the friction at the die-workpiece interface, and the height to diameter ratio. Information about the softening with recovery provides an insight into the hardness and microstructure homogeneity in HPT processed work-piece, which is useful in the design of HPT process.

Sign in / Sign up

Export Citation Format

Share Document