Constitutive Modeling for Impact Simulation of Random Fiber Composite Structures

1999 ◽  
Author(s):  
Haeng-Ki Lee ◽  
Srdan Simunovic
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Composite Structures ◽  
Fiber Composite ◽  
Damage Model ◽  
Yield Function ◽  
Progressive Damage ◽  
Finite Element Code ◽  
Effective Yield ◽  
Damage Constitutive Model

Abstract A constitutive model for progressive crushing is presented to predict impact behavior and damage evolution in random carbon fiber polymer matrix composites (RCFPMCs). Based on the ensemble-volume averaging process and first-order effects of eigenstrains due to the existence of prolate fibers, an effective yield criterion is derived to estimate the overall elastoplastic damage responses. First, an effective elastoplastic constitutive damage model for aligned fiber-reinforced composites is proposed. A micromechanical damage constitutive model for RCFPMCs is then developed. The governing field equations and overall yield function for aligned fiber-orientations are averaged over all orientations to obtain the constitutive relations and effective yield function of RCFPMCs. Finally, the complete progressive damage constitutive model is implemented into finite element code DYNA3D to solve large scale problems such as automobile components and systems. An advantage of the progressive damage analysis is that the information from the progressive damage model can be implemented into finite element code as material input properties and thus the calculations required in the constitutive model can be greatly reduced.

Numerical model for composite patch repair of notched aluminum plates under impact loading

2021 ◽  
pp. 146442072098337
Author(s):  
Umut Caliskan ◽  
Recep Ekici ◽  
Ayse Yildiz Bayazit ◽  
M Kemal Apalak
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Composite Structures ◽  
Impact Damage ◽  
Damage Model ◽  
Three Dimensional ◽  
Patch Repair ◽  
Progressive Damage ◽  
Damage Models ◽  
Composite Patch

The damaged area for various structures can be effectively repaired using composite materials. With the effect of impact, damage can occur that cannot be clearly seen in the inner structure of a laminated composite. This can cause delamination and other damage modes in layered composite structures. In this study, three-dimensional dynamic progressive damage analysis was performed in adhesively bonded composite patch-repaired metal notched plates under impact loads to investigate the effect of external composite patch material and thickness. Three-dimensional Hashin damage models were used for the progressive damage model. A user-defined subroutine, VUMAT was written to transfer the damage models to finite element code. By writing a separate script in Python language that relates to the damage models, the weakness in the laminate of the composite patch was transferred to the finite element model with a different degradation model proposed. It was found that plastic deformations occurring after impact damage in the notched metal plates was prevented by the use of composite patches. While glass and carbon fiber exhibit similar behavior at lower impact velocities, the progress of damage is prevented by increasing patch thickness. These behaviors were confirmed by the numerical model and showed an advanced agreement with experimental results.

scholarly journals Rock Failure Analysis Based on a Coupled Elastoplastic-Logarithmic Damage Model

2017 ◽  
Vol 62 (4) ◽  
pp. 753-774
Author(s):  
M. Abdia ◽  
H. Molladavoodi ◽  
H. Salarirad
Keyword(s):  
Constitutive Model ◽  
Plastic Flow ◽  
Mechanical Response ◽  
Damage Model ◽  
Yield Function ◽  
Irreversible Thermodynamics ◽  
Stiffness Degradation ◽  
Shear Stresses ◽  
Rock Materials ◽  
Damage Process

Abstract The rock materials surrounding the underground excavations typically demonstrate nonlinear mechanical response and irreversible behavior in particular under high in-situ stress states. The dominant causes of irreversible behavior are plastic flow and damage process. The plastic flow is controlled by the presence of local shear stresses which cause the frictional sliding. During this process, the net number of bonds remains unchanged practically. The overall macroscopic consequence of plastic flow is that the elastic properties (e.g. the stiffness of the material) are insensitive to this type of irreversible change. The main cause of irreversible changes in quasi-brittle materials such as rock is the damage process occurring within the material. From a microscopic viewpoint, damage initiates with the nucleation and growth of microcracks. When the microcracks length reaches a critical value, the coalescence of them occurs and finally, the localized meso-cracks appear. The macroscopic and phenomenological consequence of damage process is stiffness degradation, dilatation and softening response. In this paper, a coupled elastoplastic-logarithmic damage model was used to simulate the irreversible deformations and stiffness degradation of rock materials under loading. In this model, damage evolution & plastic flow rules were formulated in the framework of irreversible thermodynamics principles. To take into account the stiffness degradation and softening on post-peak region, logarithmic damage variable was implemented. Also, a plastic model with Drucker-Prager yield function was used to model plastic strains. Then, an algorithm was proposed to calculate the numerical steps based on the proposed coupled plastic and damage constitutive model. The developed model has been programmed in VC++ environment. Then, it was used as a separate and new constitutive model in DEM code (UDEC). Finally, the experimental Oolitic limestone rock behavior was simulated based on the developed model. The irreversible strains, softening and stiffness degradation were reproduced in the numerical results. Furthermore, the confinement pressure dependency of rock behavior was simulated in according to experimental observations.

Analysis of Wrinkled Membranes Bounded With Macro-Fiber Composite (MFC) Actuators

2010 ◽  
Author(s):  
Alireza Doosthoseini ◽  
Armaghan Salehian ◽  
Matthew Daly
Keyword(s):  
Finite Element ◽  
Fiber Composite ◽  
The Other ◽  
Horizontal Direction ◽  
Finite Element Code ◽  
Rectangular Shape ◽  
Macro Fiber Composite

In this paper we focus on a study which involves quantifying the effects of Macro Fiber Composite (MFC) actuators on the pattern and magnitude of wrinkles in a membrane when exposed to various loadings. An ABAQUS finite element code is employed for this research. The membrane in this study has a rectangular shape which is clamped at one edge and is free to move in the horizontal direction at the other edge. MFC actuators are bounded to the membrane to make a bimorph configuration.

scholarly journals A progressive damage model of textile composites on meso-scale using finite element method: static damage analysis

2013 ◽  
Vol 48 (25) ◽  
pp. 3091-3109 ◽  
Author(s):  
Jian Xu ◽  
Stepan Vladimirovitch Lomov ◽  
Ignaas Verpoest ◽  
Subbareddy Daggumati ◽  
Wim Van Paepegem ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Damage Model ◽  
Textile Composites ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Progressive Damage Model ◽  
Meso Scale ◽  
Element Method

Multi-Axial Concrete Models for Nonlinear Analysis

2014 ◽  
Vol 1065-1069 ◽  
pp. 2099-2103
Author(s):  
Hu Qi ◽  
Yun Gui Li
Keyword(s):  
Constitutive Model ◽  
Nonlinear Analysis ◽  
Damage Model ◽  
Nonlinear Characteristic ◽  
Plastic Model ◽  
Elastic Plastic ◽  
Plastic Damage ◽  
Damage Constitutive Model

The most widely used multi-axial concrete models including elastic-plastic model and elastic plastic damage model are expounded and it is recognized that the elastic plastic damage model is more reasonable to reflect nonlinear characteristic of concrete. The development and application of elastic plastic damage model is comprehensively appraised and a practical elastic plastic damage constitutive model is established. Finally the dynamic trend of constitutive model of concrete development is introduced.

Damage Theoretical Analysis of 2.5D C/SiC Composites under Tensile and Shear Loading

2010 ◽  
Vol 150-151 ◽  
pp. 330-333
Author(s):  
Yan Jun Chang ◽  
Ke Shi Zhang ◽  
Gui Qiong Jiao ◽  
Jian Yun Chen
Keyword(s):  
Constitutive Model ◽  
Damage Evolution ◽  
Yield Function ◽  
Shear Loading ◽  
Isotropic Hardening ◽  
Shear Tests ◽  
Energy Equivalence ◽  
Damage Constitutive Model ◽  
Sic Composites ◽  
Nonlinear Hardening

An anisotropic damage constitutive model is developed to describe the damage behavior of C/SiC composites. Different kinematic and isotropic hardening functions were employed in damage yield function to describe accurately the damage nonlinear hardening. The damage variable is defined by the principle of energy equivalence. The degradation of stiffness and the unrecoverable deformation induced by micro-crack propagation were considered in this model. The constants of constitutive model are identified and the damage evolution processes under tensile and shear loading. Uniaxial tension and shear tests have been used to valid the constitutive model to C/SiC composites.

Simulation of Post Failure Response in Fiber Composites

2011 ◽  
Author(s):  
Badrinath Veluri ◽  
Henrik Myhre Jensen
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Constitutive Model ◽  
Failure Mechanism ◽  
Inclination Angle ◽  
Layered Materials ◽  
Fiber Composites ◽  
Finite Element Code ◽  
Compressive Failure ◽  
Localization Of Deformation

This study focuses on the compressive failure mechanism in the form of kinkband formation in fiber composites. Taking into account the non-linearities of the constituents, a constitutive model for unidirectional layered materials has been developed and incorporated as a user material in a commercially available finite element code to study effects of kinkband inclination angle and micro-geometry on kinkband formation. The localization of deformation into a single kinkband is studied. In the post failure regime a state is reached where deformation in the kinkband gets stabilized and the kinkband broadens under steady-state conditions.

Statistical Damage Constitutive Model for Concrete under Biaxial Tension

2013 ◽  
Vol 438-439 ◽  
pp. 183-186
Author(s):  
Wei Feng Bai ◽  
Jun Hong Zhang ◽  
Jun Feng Guan ◽  
Ying Cui
Keyword(s):  
Constitutive Model ◽  
Biaxial Tension ◽  
Damage Model ◽  
Damage Mechanism ◽  
Deformation Properties ◽  
Damage Constitutive Model ◽  
Strength And Deformation ◽  
Statistical Damage Constitutive Model ◽  
Damage Theory ◽  
Statistical Damage

Based on the statistical damage theory and the experimental phenomena, the statistical damage constitutive model for concrete under biaxial tension is proposed. The two meso-scale damage modes, rupture and yield are considered, and the whole damage evolution process is driven by the principal tensile damage strain. The results show that the proposed statistical damage model can accurately predict the constitutive behavior in the uniform damage phase for concrete under biaxial tension. The damage mechanism is discussed in the view point of biaxial strength and deformation properties.

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