Micromechanics-Based Elastoplastic and Damage Modeling of Particle Reinforced Composites

Materials ◽  
2004 ◽  
Author(s):  
H. T. Liu ◽  
Lizhi Sun ◽  
J. W. Ju
Keyword(s):  
Damage Model ◽  
Local Stress ◽  
Damage Mechanism ◽  
Elastic Stiffness ◽  
Interfacial Debonding ◽  
Isotropic Hardening ◽  
Flow Rule ◽  
Elastoplastic Behavior ◽  
Micromechanical Damage ◽  
The Matrix

A micromechanical damage model is proposed to predict the effective elastoplastic behavior of ductile composites containing randomly dispersed particles. The interfacial debonding between particles and the matrix is considered as the primary micromechanical damage mechanism. The debonded isotropic elastic reinforcements are replaced by equivalent anisotropic elastic inclusions. The interfacial debonding process is simulated by three-dimensional debonding angles. After the local stress field in the matrix is calculated, the homogenization averaging procedure is employed to estimate the effective elastic stiffness and yield function of the composites. The associative plastic flow rule and the isotropic hardening law are postulated based on the continuum plasticity theory. As applications, the overall elastoplastic and damage constitutive behavior of the composites under various loading conditions is numerically simulated and compared with available experimental results.

Ductile Fracture Modeling of DH36 Grade Steels

2018 ◽  
Author(s):  
Burak Can Cerik ◽  
Sung-Ju Park ◽  
Joonmo Choung
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fracture Surface ◽  
Ductile Fracture ◽  
Stress Triaxiality ◽  
Local Stress ◽  
Fracture Initiation ◽  
Isotropic Hardening ◽  
Flow Rule ◽  
Element Analysis

A Hosford-Coulomb type ductile fracture surface was developed for DH36 grade steels. The fracture experiments reported in the literature, which consist of tests with notched tensile specimens, tensile specimens with a central hole, shear specimen and disc specimens for punch specimens, were utilized in a detailed finite element analysis of each experiment to evaluate the evolution of local stress and strain fields and identify plasticity and fracture response of DH36. The developed plasticity model consists of a von Mises yield surface, an associated flow rule and a combined Swift-Voce type isotropic hardening rule. The loading paths to fracture initiation were determined in terms of stress triaxiality and normalized Lode angle parameter histories. Finally, the Hosford-Coulomb fracture surface was calibrated using the finite element analysis results and adapting a linear damage accumulation law.

scholarly journals A Micromechanical Anisotropic Damage Model for Brittle Rocks With Non-Associated Plastic Flow Rule Under True Triaxial Compressive Stresses

2021 ◽  
Vol 9 ◽  
Author(s):  
Shuangshuang Yuan ◽  
Qizhi Zhu ◽  
Wanlu Zhang ◽  
Jin Zhang ◽  
Lunyang Zhao
Keyword(s):  
Plastic Flow ◽  
Damage Model ◽  
Local Stress ◽  
Inclusion Problem ◽  
Flow Rule ◽  
Model Parameters ◽  
Anisotropic Damage ◽  
True Triaxial ◽  
Brittle Rocks ◽  
Plastic Flow Rule

A micromechanical anisotropic damage model with a non-associated plastic flow rule is developed for describing the true triaxial behaviors of brittle rocks. We combine the Eshelby’s solution to the inclusion problem with the framework of irreversible thermodynamics. The main dissipative mechanisms of inelastic deformation due to the frictional sliding and damage by microcrack propagation are strongly coupled to each other. A Coulomb-type friction criterion is formulated in terms of the local stress applied onto the microcracks as the yielding function. The back-stress term contained in this local stress plays a critical role in describing the material’s hardening/softening behaviors. With a non-associated flow rule, a potential function is involved. Some analytical analysis of the non-associated micromechanical anisotropic damage model are conducted, which are useful for the model parameters calibration. The proposed model is used to simulate the laboratory tests on Westerly granite under true triaxial stresses. Comparing the numerical simulation results provided by the models with associated/non-associated plastic flow rule and experimental results, it is clear that the proposed non-associated model gives a better prediction than the previous associated model.

scholarly journals Quantitative Anisotropic Damage Mechanism in a Forged Aluminum Alloy Studied by Synchrotron Tomography and Finite Element Simulations

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Yang Shen ◽  
Thilo F. Morgeneyer ◽  
Jérôme Garnier ◽  
Lucien Allais ◽  
Lukas Helfen ◽  
...  
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Volume Fraction ◽  
Microstructural Analysis ◽  
Damage Model ◽  
Longitudinal Direction ◽  
Damage Mechanism ◽  
Finite Element Simulations ◽  
Synchrotron Tomography ◽  
Micromechanical Damage

A highly anisotropic toughness behavior has been revealed on a forged AA6061 aluminum alloy by toughness tests with CT specimens. The toughness values with specimens loaded on the longitudinal direction are larger than that loaded on the transverse direction due to the anisotropic shape and distribution of coarse precipitates induced by the morphological anisotropy of grains during forging process. Synchrotron radiation computed tomography analysis on as-received material and arrested cracks revealed different fracture modes for the two loading configurations. The damage mechanism has been validated by finite element simulations based on the Gurson–Tvergaard–Needleman micromechanical damage model with different sets of damage parameters for the two loading configurations obtained from quantitative void volume fraction analysis on SRCT data, in situ SEM experiments, and SRCT microstructural analysis.

On the Modeling of Fibers Embedding in Aluminum Using Ultrasonic Consolidation

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Abba A. Abubakar ◽  
Shafique M. A. Khan ◽  
Samir Mekid
Keyword(s):  
Fiber Optics ◽  
Structural Model ◽  
Damage Model ◽  
Mechanical Analysis ◽  
Isotropic Hardening ◽  
Flow Rule ◽  
Ultrasonic Consolidation ◽  
Sic Fiber ◽  
Real Material ◽  
Extent Of Damage

Ultrasonic consolidation of fiber optics in metals is of major importance allowing surface embedding and protecting the fibers from exposure to open environment. The paper investigates the computational modeling of this process of embedding fibers at the aluminum subsurface. This new method provides an opportunity to develop sensory materials (Mekid et al., 2015, “Towards Sensor Array Materials: Can Failure be Delayed?” Sci. Technol. Adv. Mater., 16(3), p. 034607) and new types of nervous materials (Mekid and Kwon, 2009, “Nervous Materials: A New Approach for Better Control, Reliability and Safety of Structures,” Sci. Adv. Mater., 1(3), pp. 276–285) for structural health monitoring applications. A thermo-mechanical analysis of embedding SiC fiber in aluminum substrate has been conducted. The temperature distribution was obtained using a thermal model with process-dependent heat flux at the sonotrode/foil interface, which is coupled to the structural model in an iterative manner for simulating fiber embedment. The structural model uses a process-dependent plastic flow rule with an isotropic hardening model. A ductile damage model is employed for the first time in simulating such problems in addition to the use of real material properties of the fiber, which has resulted in better numerical results. Both of these factors help in determining the extent of damage particularly to the fiber/sensor being embedded. The experimental test has shown good agreement.

Elastoplastic Behavior of Particle Reinforced Composites Considering the Effect of Interfacial Debonding

2007 ◽  
Vol 340-341 ◽  
pp. 125-130
Author(s):  
Jian Guo Ning ◽  
Fang Jiang
Keyword(s):  
Metal Matrix ◽  
Uniaxial Stress ◽  
Isotropic Hardening ◽  
Interface Debonding ◽  
Reinforced Composites ◽  
Elastoplastic Behavior ◽  
Hardening Law ◽  
The Matrix ◽  
Modulus Method ◽  
Traction Boundary Conditions

Based on Mori-Tanaka’s concept of average stress in the matrix and Eshelby’s equivalent inclusions theory, the stress or strain of the matrix, the reinforced particles and the composite are derived under a prescribed traction boundary conditions. The plastic strains and strains due to thermal mismatch between matrix and reinforced phase are considered as eigenstrains. The matrix and composite are postulated isotropic and the matrix satisfies isotropic hardening law. The interface debonding is decided by the tensile strength of the particles whose debonding probability is described by Weibull distribution function. Then the overall elastoplastic constitutive relation of spherical particle-reinforced metal matrix composite is derived by secant modulus method considering the interface debonding. The theoretical uniaxial stress-strain bebavior of the composite agrees well with the experimental curves.

Statistical micromechanical damage model for SH-SFRC under tensile load considering the interfacial slip-softening and matrix spalling effects

2021 ◽  
pp. 105678952110112
Author(s):  
Hehua Zhu ◽  
Xiangyang Wei ◽  
J Woody Ju ◽  
Qing Chen ◽  
Zhiguo Yan ◽  
...  
Keyword(s):  
Strain Hardening ◽  
Steel Fiber ◽  
Damage Model ◽  
Fiber Reinforced Concrete ◽  
Uniaxial Tensile ◽  
Interfacial Slip ◽  
Fiber Reinforced ◽  
Micromechanical Damage ◽  
The Impact ◽  
Micromechanical Damage Model

Strain hardening behavior can be observed in steel fiber reinforced concretes under tensile loads. In this paper, a statistical micromechanical damage framework is presented for the strain hardening steel fiber reinforced concrete (SH-SFRC) considering the interfacial slip-softening and matrix spalling effects. With a linear slip-softening interface law, an analytical model is developed for the single steel fiber pullout behavior. The crack bridging effects are reached by averaging the contribution of the fibers with different inclined angles. Afterwards, the traditional snubbing factor is modified by considering the fiber snubbing and the matrix spalling effects. By adopting the Weibull distribution, a statistical micromechanical damage model is established with the fracture mechanics based cracking criteria and the stress transfer distance. The comparison with the experimental results demonstrates that the proposed framework is capable of reproducing the SH-SFRC’s uniaxial tensile behavior well. Moreover, the impact of the interfacial slip-softening and matrix spalling effects are further discussed with the presented framework.

Sign in / Sign up

Export Citation Format

Share Document