scholarly journals A Large-Deformation Gradient Damage Model for Single Crystals Based on Microdamage Theory

2020 ◽  
Vol 10 (24) ◽  
pp. 9142
Author(s):  
Ozgur Aslan ◽  
Emin Bayraktar
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Flow Resistance ◽  
Large Deformations ◽  
Deformation Gradient ◽  
Damage Model ◽  
Anisotropic Damage ◽  
Finite Element Software ◽  
Mesh Dependency ◽  
Micromorphic Theory

This work aims at the unification of the thermodynamically consistent representation of the micromorphic theory and the microdamage approach for the purpose of modeling crack growth and damage regularization in crystalline solids. In contrast to the thermodynamical representation of the microdamage theory, micromorphic contribution to flow resistance is defined in a dual fashion as energetic and dissipative in character, in order to bring certain clarity and consistency to the modeling aspects. The approach is further extended for large deformations and numerically implemented in a commercial finite element software. Specific numerical model problems are presented in order to demonstrate the ability of the approach to regularize anisotropic damage fields for large deformations and eliminate mesh dependency.

scholarly journals Gradient Nonlocal Enhanced Microprestress-Solidification Theory and Its Finite Element Implementation

2021 ◽  
Vol 8 ◽  
Author(s):  
Teng Tong ◽  
Changqing Du ◽  
Xiaofan Liu ◽  
Siqi Yuan ◽  
Zhao Liu
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Deformation Gradient ◽  
Damage Model ◽  
Reinforced Concrete Beams ◽  
Chain Model ◽  
Finite Element Software ◽  
Order Deformation ◽  
Implicit Solver

Time-dependent responses of cracked concrete structures are complex, due to the intertwined effects between creep, shrinkage, and cracking. There still lacks an effective numerical model to accurately predict their nonlinear long-term deflections. To this end, a computational framework is constructed, of which the aforementioned intertwined effects are properly treated. The model inherits merits of gradient-enhanced damage (GED) model and microprestress-solidification (MPS) theory. By incorporating higher order deformation gradient, the proposed GED-MPS model circumvents damage localization and mesh-sensitive problems encountered in classical continuum damage theory. Moreover, the model reflects creep and shrinkage of concrete with respect to underlying moisture transport and heat transfer. Residing on the Kelvin chain model, rate-type creep formulation works fully compatible with the gradient nonlocal damage model. 1-D illustration of the model reveals that the model could regularize mesh-sensitivity of nonlinear concrete creep affected by cracking. Furthermore, the model depicts long-term deflections and cracking evolutions of simply-supported reinforced concrete beams in an agreed manner. It is noteworthy that the gradient nonlocal enhanced microprestress-solidification theory is implemented in the general finite element software Abaqus/Standard with the implicit solver, which renders the model suitable for large-scale creep-sensitive structures.

scholarly journals Numerical model of the nanoindentation test based on the digital material representation of the Ti/TiN multilayers

2015 ◽  
Vol 33 (2) ◽  
pp. 348-355 ◽  
Author(s):  
Konrad Perzyński ◽  
Radosław Wiatr ◽  
Łukasz Madej
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Cellular Automata ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Nanoindentation Test ◽  
Cellular Automata Model ◽  
Finite Element Software ◽  
Specific Morphology ◽  
Digital Material

AbstractThe developed numerical model of a local nanoindentation test, based on the digital material representation (DMR) concept, has been presented within the paper. First, an efficient algorithm describing the pulsed laser deposition (PLD) process was proposed to realistically recreate the specific morphology of a nanolayered material in an explicit manner. The nanolayered Ti/TiN composite was selected for the investigation. Details of the developed cellular automata model of the PLD process were presented and discussed. Then, the Ti/TiN DMR was incorporated into the finite element software and numerical model of the nanoindentation test was established. Finally, examples of obtained results presenting capabilities of the proposed approach were highlighted.

scholarly journals Verification of the flexion and shear behavior in masonry panels accordance to ABNT NBR 15961-1 (2011), EN 1996-1-1 (2005) and ACI TMS 530 (2013)

2018 ◽  
Vol 11 (4) ◽  
pp. 673-685
Author(s):  
R. C. MATA ◽  
C. S. RAMOS ◽  
M. L. C. SILVA
Keyword(s):  
Computer Simulation ◽  
Finite Element ◽  
Numerical Model ◽  
Design Criteria ◽  
Two Dimensional ◽  
Finite Element Software ◽  
Modelling Procedure ◽  
Increasing Trend ◽  
American Standard ◽  
Compression Level

Abstract This paper presents a numerical analysis of the mechanical behavior of structural masonry panels submitted to horizontal and vertical stresses. To evaluate the design process of these structures, the results obtained by the computer simulations were compared with the results determined by the design criteria of ABNT NBR 15961-1 (2011), ACI TMS 530 (2013) and EN 1996-1-1 (2005). The finite element software DIANA v.9.3 was used to simulate two-dimensional models with the simplified micro modelling procedure. The results obtained by the normative standards were more conservative than the results of the numerical model, as expected. With the increase of the pre-compression level, the computer simulation has demonstrated the increasing trend of the values of resistant forces, besides the change of the way of rupture of the panels. Among the three standards evaluated, the American Standard was the most conservative.

scholarly journals Finite Element Software for Rubber Products Design

2018 ◽  
Vol 3 (1) ◽  
pp. 13-20
Author(s):  
Dávid Huri
Keyword(s):  
Finite Element ◽  
Complex Analysis ◽  
Large Deformations ◽  
Material Behavior ◽  
Nonlinear Material ◽  
Material Models ◽  
Finite Element Software ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Different Types

Automotive rubber products are subjected to large deformations during working conditions, they often contact with other parts and they show highly nonlinear material behavior. Using finite element software for complex analysis of rubber parts can be a good way, although it has to contain special modules. Different types of rubber materials require the curve fitting possibility and the wide range choice of the material models. It is also important to be able to describe the viscoelastic property and the hysteresis. The remeshing possibility can be a useful tool for large deformation and the working circumstances require the contact and self contact ability as well. This article compares some types of the finite element software available on the market based on the above mentioned features.

scholarly journals Finite Element Study on the Shear Capacity of Traditional Joints between Walls Made of AAC Masonry Units

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4035
Author(s):  
Marcin Kozłowski ◽  
Iwona Galman ◽  
Radosław Jasiński
Keyword(s):  
Finite Element ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Numerical Model ◽  
Fracture Energy ◽  
Shear Capacity ◽  
Nonlinear Behaviour ◽  
Structural Behaviour ◽  
Finite Element Software ◽  
Masonry Units

This paper presents the development of a numerical model aimed at the simulation of nonlinear behaviour of traditional joints between walls made of autoclaved aerated concrete (AAC) masonry units. Nonlinear behaviour and cracking of AAC and mortar were simulated using the concrete damaged plasticity (CDP) model available in the ABAQUS finite element software. The paper also presents and discusses the results of an experimental campaign involving testing six T-shaped, monosymmetric samples with traditional joints between walls loaded in shear. The results were used to validate the numerical model. The validation confirmed that the model is capable of producing accurate results and predicting the structural behaviour with a reasonably good accuracy in elastic and post-elastic stages. Furthermore, a sensitivity study was conducted, in which the variation of elastic modulus, Poisson’s ratio, tensile strength, compression strength and fracture energy of AAC was investigated. Results showed that the variation of elastic modulus, tensile strength and fracture energy is most critical to the structural behaviour of the model, while variation of the remaining parameters has a negligible effect on the results.

scholarly journals Numerical Investigation of Tool Parameters Influence on the Interlock Forming During Flat Clinching Process

2021 ◽  
Author(s):  
Zhiyong Wang ◽  
Shanling Han ◽  
Zhiyong Li ◽  
Yong Li
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Linear Relationship ◽  
Numerical Investigation ◽  
Vital Role ◽  
Blank Holder ◽  
Finite Element Software ◽  
Punch Radius ◽  
Deform 2D ◽  
The Relationship

Abstract Tool parameters play a vital role in the mechanical interlock formation during the flat clinching process, to understand the influence of tool parameters on the interlock formation, the finite element software DEFORM-2D was used to build the numerical model of the flat clinching process, and the numerical model was verified by the experiment. The influences of the punch radius, punch fillet radius, and blank holder radius on the interlock formation of the clinched joint were investigated using the numerical model. Then, the relationship between the punch radius and blank holder radius was studied. The results showed that the interlock gradually increases with the increase of the blank holder radius, after that, the interlock begins to decrease. To maximize the interlock, the punch radius and the blank holder radius should be increased simultaneously. It can be concluded that the blank holder radius and the punch radius should keep in a linear relationship when designing the geometric dimensions of the flat clinch tools, which can promote the application of flat clinching process in car body manufacturing.

Multiple Crack Detection of Pipes Using PZT-Based Guided Waves

2013 ◽  
Vol 448-453 ◽  
pp. 3702-3708 ◽  
Author(s):  
Shi Yan ◽  
Ji Qi ◽  
Nai Zhi Zhao ◽  
Yang Cheng ◽  
Sheng Wen Jun Qi
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Model ◽  
Crack Detection ◽  
Guided Waves ◽  
Arrival Time ◽  
Ultrasonic Guided Waves ◽  
Multiple Crack ◽  
Finite Element Software ◽  
Reflected Signal

This paper focuses on the multiple crack detection of steel pipelines using PZT-based guided waves. Numerical simulations of cracked pipes based on ultrasonic guided-waves are conducted by using the ANSYS finite element software. Based on the analysis of the reflected signal, the arrival time of the crack reflection waves are determined and the crack positions are accurately evaluated by the calculation of the travel time and group velocity of the PZT-based guided waves. The crack parameters are numerically altered to determine how the parameters impact the sensitive degree of the pipe crack damage. To validate the efficiency of the numerical simulation, an experiment of the multiple crack detection for the same parameter pipe with the numerical model is performed in the laboratory, and the results match well with the numerical simulation.

Experimental and Numerical Studies of S2-Glass Fiber/Toughened Epoxy Composite Beams Subject to Drop-Weight or Ballistic Impact

2007 ◽  
Author(s):  
E. Sevkat ◽  
B. M. Liaw ◽  
F. Delale ◽  
B. B. Raju
Keyword(s):  
Finite Element ◽  
Impact Force ◽  
Damage Model ◽  
Composite Beams ◽  
Ballistic Impact ◽  
Nonlinear Finite Element ◽  
Experimental Results ◽  
Anisotropic Damage ◽  
Drop Weight ◽  
Weight Impact

A combined experimental and 3-D dynamic nonlinear finite element approach was adopted to study composite beams subject to drop-weight or ballistic impact. The composite specimens, made of S2 glass-reinforced toughened epoxy (44% fiber volume fraction, cured at 350°F), had 24 layers (approximately 6.35 mm) with various stacking sequences. They were damaged by impacts using either an Instron-Dynatup 8520 instrumented drop-weight impact tester (low-velocity impact) or an in-house high-speed gas gun (ballistic impact). For both types of tests, the time-histories of dynamic strains induced during impact were recorded using strain gages mounted on the front and back of the composite beam specimen. For drop-weight impact tests, the time history of impact force was also recorded; whereas for ballistic impact tests, only the impact velocity was calculated from the recorded change in voltage outputs, which resulted from the traversing of the impactor through two optical paths formed by two sets of diode laser-amplified photo diode pairs. The commercially available 3-D dynamic nonlinear finite element software, LS-DYNA, incorporated with a proposed nonlinear anisotropic damage model, was then used to simulate the experimental results. Good agreement between experimental and FEM results can be seen from comparisons of dynamic strain and impact force histories and damage patterns. Once the proposed nonlinear anisotropic damage model was verified by experimental results, further finite element simulations were conducted to predict the ballistic limit velocity (V50) for penetration prevention.

Damage Simulation of Masonry Wall Based on the Finite Element Software Abaqus

2014 ◽  
Vol 1008-1009 ◽  
pp. 1367-1370
Author(s):  
Fu Xiao Chen ◽  
Wen Fang Zhang
Keyword(s):  
Finite Element ◽  
Damage Model ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Simulation Methods ◽  
Failure Characteristics ◽  
Advantages And Disadvantages ◽  
Finite Element Software ◽  
Concrete Damage ◽  
Damage Simulation

In this paper, I use the finite element software abaqus to simulate the damage form of masonry walls in the case of force. Advantages and disadvantages of various simulation methods are fully considered. Masonry walls are considered homogeneous isotropic continuum,was built by using integrated model. And I adopt concrete damage model to define material properties. The results showed that the model in this paper well simulated the failure characteristics of the wall.

Numerical Simulation for Thick-Walled Hollow Axle during Cross Wedge Rolling

2011 ◽  
Vol 337 ◽  
pp. 270-273 ◽  
Author(s):  
Yang Jiang ◽  
Bao Yu Wang ◽  
Zheng Huan Hu ◽  
Jian Guo Lin
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Model ◽  
Rolling Process ◽  
Cross Wedge Rolling ◽  
Finite Element Software ◽  
Temperature Distributions ◽  
Simulation Results ◽  
Deform 3D

The paper investigates a process of cross wedged rolling (CWR) for manufacturing thick-walled hollow axles. A finite element numerical model coupled deformation and heat transfer of CWR is established using commercial finite element software DEFORM-3D. The rolling process of hollow axle during CWR is simulated successfully. The stress, strain and temperature distributions of workpiece are obtained and analyzed. The simulation results show that forming thick-walled hollow axles through CWR is feasible.

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