A Dynamic Three Invariant Cap-Viscoplastic Damage Model for Ultrahigh-Performance Concrete

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Bhasker Paliwal ◽  
Youssef Hammi ◽  
Mei Chandler ◽  
Robert D. Moser ◽  
Mark F. Horstemeyer
Keyword(s):  
Damage Model ◽  
Compressive Loading ◽  
Dynamic Strain ◽  
Army Corps ◽  
Army Corps Of Engineers ◽  
Damage Initiation ◽  
Rate Dependent ◽  
Proposed Model ◽  
Damage Constitutive Model ◽  
Reactive Powder

A new dynamic strain rate-dependent elasto-viscoplastic damage constitutive model for ultrahigh-performance concrete (UHPC) is developed by incorporating Duvaut–Lions viscoplasticity generalized to multisurface plasticity followed by rate-dependent dynamic damage initiation and evolution under multiaxial loading, to our previous elastoplastic damage model. The predictive capability of the proposed model is compared against experimental results and experimentally observed features from tests on Cor-Tuf concrete, a reactive powder concrete (RPC) and a proprietary UHPC developed by the U.S. Army Corps of Engineers. These experiments were conducted under various compressive loading conditions under low to high confinement and different strain rates, and model predictions demonstrate excellent agreement with these results.

STOCHASTIC VISCOUS-DAMAGE CONSTITUTIVE MODEL FOR CONCRETE

2013 ◽  
Vol 07 (03) ◽  
pp. 1350027
Author(s):  
JIE LI ◽  
QIAOPING HUANG
Keyword(s):  
Damage Model ◽  
Damage Mechanism ◽  
Failure Behavior ◽  
Strain Rates ◽  
Rate Dependency ◽  
Rate Dependent ◽  
Proposed Model ◽  
Model Predictions ◽  
Damage Constitutive Model ◽  
Stochastic Damage

A new rate-dependent stochastic damage model for the dynamic modeling of concrete is presented in the paper. This model is formulated on the basis of the stochastic damage model, from which, the static stochastic evolution of damage is strictly derived. Then, rate dependency of concrete is included by means of viscous-damage mechanism. The model predictions are tested against experimental results on concrete specimens that cover different strain rates. The results demonstrate the proposed model may predict dynamic failure behavior of concrete quite well.

scholarly journals A Coupled Plastic Damage Model for Concrete considering the Effect of Damage on Plastic Flow

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Feng Zhou ◽  
Guangxu Cheng
Keyword(s):  
Damage Model ◽  
Compressive Loading ◽  
Plain Concrete ◽  
Yield Function ◽  
Reduction Factor ◽  
Loading History ◽  
Plastic Yield ◽  
Plastic Damage ◽  
Compliance Tensor ◽  
Proposed Model

A coupled plastic damage model with two damage scalars is proposed to describe the nonlinear features of concrete. The constitutive formulations are developed by assuming that damage can be represented effectively in the material compliance tensor. Damage evolution law and plastic damage coupling are described using the framework of irreversible thermodynamics. The plasticity part is developed without using the effective stress concept. A plastic yield function based on the true stress is adopted with two hardening functions, one for tensile loading history and the other for compressive loading history. To couple the damage to the plasticity, the damage parameters are introduced into the plastic yield function by considering a reduction of the plastic hardening rate. The specific reduction factor is then deduced from the compliance tensor of the damaged material. Finally, the proposed model is applied to plain concrete. Comparison between the experimental data and the numerical simulations shows that the proposed model is able to describe the main features of the mechanical performances observed in concrete material under uniaxial, biaxial, and cyclic loadings.

Material orthotropy effects on progressive damage analysis of open-hole composite laminates under tension

2017 ◽  
Vol 36 (20) ◽  
pp. 1473-1486 ◽  
Author(s):  
Song Zhou ◽  
Yi Sun ◽  
Boyang Chen ◽  
Tong-Earn Tay
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Tensile Loading ◽  
Progressive Damage ◽  
Cohesive Elements ◽  
Damage Initiation ◽  
Proposed Model ◽  
Open Hole

The sizes effects on the strengths of open-hole fibre-reinforced composite laminates subjected to tensile loading (OHT) have been investigated widely. However, little attention has been paid to the influence of material orthotropy. This paper presents a progressive damage model for the model failure of notched laminates under tensile loading based on continuum damage mechanics and cohesive elements. The effects of orthotropy on the failure of notched laminates with seven different ply sequences are investigated by our proposed model. The prediction results adopting the Hoffman and Pinho failure criterions to determine matrix damage initiation are compared with the results of experiments. Our proposed models are able to predict the strong influence of orthotropy on strengths of open-hole laminate under tension, and model using Pinho criterion can predict the open-hole tension strength most accurately.

Flow Stress and Damage Behavior of C45 Steel Over a Range of Temperatures and Loading Rates

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Farid H. Abed ◽  
Mohammad H. Saffarini ◽  
Akrum Abdul-Latif ◽  
George Z. Voyiadjis
Keyword(s):  
Coupling Effect ◽  
Damage Model ◽  
Ductile Failure ◽  
Tensile Tests ◽  
Dynamic Strain ◽  
Strain Rates ◽  
Sem Images ◽  
Proposed Model ◽  
Static Tensile ◽  
Structural Responses

This research aims to describe the behavior of C45 steel and provide better understanding of the thermomechanical ductile failure that occurs due to accumulation of microcracks and voids along with plastic deformation to enable proper structural design, and hence provide better serviceability. A series of quasi-static tensile tests are conducted on C45 steel at a range of temperatures between 298 K and 923 K for strain rates up to 0.15 s−1. Drop hammer dynamic tests are also performed considering different masses and heights to study the material response at higher strain rates. Scanning electron microscopy (SEM) images are taken to quantify the density of microcracks and voids of each fractured specimens, which are needed to define the evolution of internal defects using an energy-based damage model. The coupling effect of damage and plasticity is incorporated to accurately define the constitutive relation that can simulate the different structural responses of this material. Good correlation was observed between the proposed model predictions and experiments particularly at regions where dynamic strain aging (DSA) is not present.

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