scholarly journals Ballistic Impact and Virtual Testing of Woven FRP Laminates

2021 ◽  
Vol 5 (5) ◽  
pp. 115
Author(s):  
Ioannis K. Giannopoulos ◽  
Mehdi Yasaee ◽  
Nikolaos Maropakis
Keyword(s):  
Numerical Models ◽  
Progressive Failure ◽  
Computational Cost ◽  
Carbon Composite ◽  
Steel Ball ◽  
Element Analysis ◽  
General Behaviour ◽  
Explicit Finite Element ◽  
The Impact ◽  
Fidelity Model

The aim of the work was to investigate the numerical simulations correlation with the experimental behaviour of steel ball high velocity impact onto a 2 × 2 twill woven carbon composite laminate. The experimental set up consisted of a pressurised gas-gun able to shot steel ball projectiles onto two different composite plate layup configurations of plates made of the same composite material fabric. Subsequently, the experiments were replicated using the LSDYNA explicit finite element analysis software package. Progressive failure numerical models of two different fidelity levels were constructed. The higher fidelity model was simulating each of the plys of the composite panels separately, tied together using cohesive zone modelling properties. The lower fidelity model consisted of a single layer plate with artificial integration points for each ply. The simulation results came out to be in satisfactory agreement with the experimental ones. While the delamination extent was moderately under predicted by the higher fidelity model, the general behaviour was complying with the experimental results. The lower fidelity model was consistent in representing the damage of the panel during the impact and better predicted the impactor residual velocities due to the better matching of the pane stiffness. Despite the competency of the higher fidelity model to capture the damage of the laminate in a more detailed level, the computational cost was 80% higher than the lower fidelity case, which rendered that model impractical against the lower fidelity one, to use in larger models representing more substantial or more complex structures.

Experimental and simulation investigation on BVID and CAI behaviors of CFRP laminates manufactured by RTM technology

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fang Chen ◽  
Weixing Yao ◽  
Wen Jiang
Keyword(s):  
Compressive Strength ◽  
Impact Damage ◽  
Projection Area ◽  
Element Analysis ◽  
Mechanical Fracture ◽  
Content Type ◽  
Explicit Finite Element ◽  
Compression Load ◽  
Cfrp Laminates ◽  
The Impact

Purpose The purpose of this paper is to synthetically investigate the impact damage responses of carbon fiber reinforced polymer (CFRP) and its influence on the compression mechanical responses of CFRP laminates, including damage distribution, residual compressive strength and fracture morphology. Design/methodology/approach A progressive damage simulation model is developed to analyze the complicated damage responses of CFRP laminates that are manufactured by resin transfer method (RTM) technology. Based on the ABAQUS/explicit finite element analysis solver, a VUMAT code is proposed to descript the composite materials’ damage behaviors under both impact and compression load. Adopting this proposed model, the primary mechanical indicators of four groups’ 5284RTM/U3160 CFRP laminates with different stacking sequences are predicted. Moreover, impact and compression after impact tests are conducted to verify the accuracy of simulation results. Findings Both simulation and experimental results show that the impact damage with low visible detectability can significantly reduce composites’ compressive strength. For all four groups’ composite laminates, the residual strength ratio is around 35% or even lower. The kernel impact damage near the plates’ geometric center promotes the degradation process of local materials and finally leads to the early occurrence of mechanical fracture. In addition, the impact damage projection area is not sensitive to the parameters of stacking sequences, while the residual compression strength is proportional to the number of 0-degree layers within whole laminates. Originality/value This study helps to understand the effect of an impact event on CFRP laminates’ compressive bearing capacity and provides a numerical method in simulating the damage responses under both impact and compression load.

FINITE ELEMENT ANALYSIS OF HONEYCOMB IMPACT ATTENUATOR

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1417-1422
Author(s):  
SEUNG-YONG YANG ◽  
SEUNG-KYU CHOI ◽  
NOHYU KIM
Keyword(s):  
Finite Element ◽  
Rigid Wall ◽  
Honeycomb Structure ◽  
Student Group ◽  
Safety Requirement ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
University Of Technology ◽  
Deformation Behaviors ◽  
The Impact

To participate in Student Formula Society of Automotive Engineers (SAE) competitions, it is necessary to build an impact attenuator that would give an average deceleration not to exceed 20g when it runs into a rigid wall. Students can use numerical simulations or experimental test data to show that their car satisfies this safety requirement. A student group to study formula cars at the Korea University of Technology and Education has designed a vehicle to take part in a SAE competition, and a honeycomb structure was adopted as the impact attenuator. In this paper, finite element calculations were carried out to investigate the dynamic behavior of the honeycomb attenuator. Deceleration and deformation behaviors were studied. Effect of the yield strength was checked by comparing the numerical results. ABAQUS/Explicit finite element code was used.

Finite Element Analysis of Electroactive and Magnetoactive Coupled Behaviors in Multi-Field Origami Structures

2017 ◽  
Author(s):  
Wei Zhang ◽  
Anil Erol ◽  
Saad Ahmed ◽  
Sarah Masters ◽  
Paris von Lockette ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Smart Materials ◽  
Electromechanical Coupling ◽  
Material Selection ◽  
Constitutive Relations ◽  
Computational Cost ◽  
Constitutive Models ◽  
Element Analysis ◽  
The Impact

Active origami designs, which incorporate smart materials such as electroactive polymers (EAPs) and magnetoactive elastomers (MAEs) into mechanical structures, have shown good promise in engineering applications. In this study, finite element analysis (FEA) models are developed using COMSOL Multiphysics software for two configurations that incorporate a combination of active and passive material layers, namely: 1) a single-notch unimorph folding configuration actuated using only external electric field and 2) a bimorph configuration which is actuated using both electric and magnetic (i.e. multifield) stimuli. Constitutive relations are developed for both electrostrictive and magnetoactive materials to model the coupled behaviors directly. Shell elements are adopted for their capacity of modeling thin films, reduction of computational cost and ability to model the intrinsic coupled behaviors in the active materials under consideration. A microstructure-based constitutive model for electromechanical coupling is introduced to capture the nonlinearity of the EAP’s relaxor ferroelectric response; the electrostrictive coefficients are then used as input in the constitutive modeling of the coupled behavior. The magnetization of the MAE is measured by experiment and then used to calculate magnetic torque under specified external magnetic field. The objective of the study is to verify the effectiveness of the constitutive models to simulate multi-field coupled behaviors of the active origami configurations. Through quantitative comparisons, simulation results show good agreement with experimental data, which is a good validation of the shell models. By investigating the impact of material selection, location, and geometric parameters, FEA can be used in design, reducing trial-and-error iterations in experiments.

Effects of Cross-Section Ovalization of Subsea Thin-Walled Bends Under In-Plane Bending

2010 ◽  
Author(s):  
Ranil Banneyake ◽  
Ayman Eltaher ◽  
Paul Jukes
Keyword(s):  
Cross Section ◽  
Computational Cost ◽  
Straight Pipe ◽  
Limit States ◽  
Element Analysis ◽  
High Tendency ◽  
Thin Walled ◽  
Plane Bending ◽  
The Cross ◽  
The Impact

Ovalization of the cross-section of bends under in-plane bending (a.k.a. Brazier effect) is a known phenomenon caused by the longitudinal stress acting on the cross-section as the pipe bends. Besides its tendency to induce stresses in the bend above what is predicted using simple beam theory, excessive cross-section ovalization is particularly critical to subsea pipes, as it can lead to collapse of the pipe under external pressure. Also, being in a plastic regime may cause the bend material to ratchet and undergo excessive strains under cyclic operational loads, especially under high-pressure high-temperature (HPHT) conditions. Ovalization normally results in local increase of stresses and could lead to failure of the bend before the bend globally reaches its limiting capacity. The offshore industry standards and design codes address the impact of initial ovality in straight pipes, but their applicability to bends is not clear. Therefore, this paper presents an investigation into the increased tendency of thin-walled bends to ovalize, and the effect of bend cross-section ovalization on their stiffness and yielding and collapse limit states, with emphasis on offshore applications. Due to the lack of analytical solutions for the bend response taking into account cross-section ovalization, finite element analysis (FEA) is used in this study. Predictions of the bend models are compared with those of straight pipe models and predictions of models of the bend made of beam elements (with pipe section) are compared with those of models made of brick /shell elements. The increased tendency of thin-walled bends to ovalize compared to straight pipes is investigated (e.g. 100 times in the linear range), and the impact and significance of ovalization in bends are assessed (e.g., stress increase of the order of 35% has been observed in some example situations). Also discussed in the paper is the selection of proper element specifications in order to accurately capture the ovalization response while keeping the computational cost manageable. Recommendations as to how to account for ovalization effects are presented. This paper helps to gain a better understanding of the response of subsea thin-walled bends under in-plane bending and their comparatively high tendency to ovalize compared to straight pipe, and emphasizes the significance of local effects such as cross-section ovalization, the overlooking of which may result in a significant underestimation of involved stresses and strains.

Modelling the Fracture of High-Hardness Armour Steel in Taylor Rod-on-Anvil Experiments

2019 ◽  
Author(s):  
Brodie McDonald ◽  
Shannon Ryan ◽  
Stephen J. Cimpoeru ◽  
Nathan Edwards ◽  
Adrian Orifici
Keyword(s):  
Shear Band ◽  
Impact Velocity ◽  
Numerical Models ◽  
Computational Cost ◽  
Stress Triaxiality ◽  
High Hardness ◽  
Material Strength ◽  
Fracture Threshold ◽  
The Impact ◽  
Armour Steel

Abstract A series of Taylor rod-on-anvil experiments have been performed to validate the predicted impact velocity fracture threshold and fracture mode of a high hardness armour steel (HHA) obtained through explicit finite element simulations. Experimentally, the rods exhibited principal shear failure, a condition that can be closely linked to adiabatic shear band (ASB) formation in high strength steel. Using a stress triaxiality and Lode angle dependent failure strain criterion (Basaran 3D fracture locus), calibrated from quasi-static mechanical characterisation tests, the simulations were unable to predict the onset of fracture observed in experiments. As such, a strength-fading criterion is proposed using a phenomenological description to capture the loss of load-carrying capacity resulting from ASB formation. The ASB criterion is based on an exponential fit to experimentally-observed instability strains measured at different average stress triaxialities in a series of tests on inclined cylindrical and modified flat-hat specimens. With the prediction of ASB formation the material strength is reduced to model the thermal softening experienced in the shear band, and fracture of the material (in the form of element erosion) remains controlled by the Basaran fracture model. Incorporating the ASB-based criterion, the numerical models were found to accurately predict both the impact velocity fracture threshold, as well as the general appearance of the observed principal shear fracture. The proposed criterion enables the effects of ASB formation to be captured in an impact simulation with little increase in computational cost.

COMPUTATIONAL INVESTIGATION OF ENERGY DISSIPATION THROUGH PROGRESSIVE FAILURE IN TAILORED COMPOSITE STRUCTURES VIA EXPLICIT FINITE ELEMENT ANALYSIS

2021 ◽  
Author(s):  
ANIRUDH SRINIVAS ◽  
D. STEFAN DANCILA
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Material ◽  
Energy Dissipation ◽  
Progressive Failure ◽  
Tensile Loading ◽  
Stress Wave Propagation ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis

A composite material tailoring concept for progressive failure under tensile loading has been previously developed, modeled, and experimentally validated by the second author and his collaborators. The concept relies upon a sequential failure process induced in a structure of series connection of parallel redundant load path elements of tailored length and strength. The resulting yield-type response under tensile loading is characterized by an increased energy dissipation compared to a reference conventional structural element of nominally identical length and crosssectional area, and of the same composite material. In this work, this composite tailoring concept is computationally investigated for IM7-8552 composite material using a dynamic, explicit finite element analysis in Abaqus. The approach offers the advantage of capturing the stress wave propagation within the model throughout the dynamic failure sequence, thereby providing a better understanding of the failure progression and the energy dissipation mechanisms at work. In this study, progressive failure of the tailored composite structure is modeled and analyzed for different configurations of lengths and widths. Model predictions are illustrated for and compared with selected tailoring configurations from the literature. Developing an explicit finite element approach for analyzing the tailoring concept opens the door to characterizing a wide variety of related, more complex configurations for which analytical solutions do not yet exist or may not even be feasible, and/or for which experimental results may be difficult or overly expensive to obtain.

scholarly journals Efficiently Simulating an Endograft Deployment: A Methodology for Detailed CFD Analyses

2020 ◽  
Vol 48 (10) ◽  
pp. 2449-2465
Author(s):  
Faidon Kyriakou ◽  
Craig Maclean ◽  
William Dempster ◽  
David Nash
Keyword(s):  
Numerical Models ◽  
Flow Analysis ◽  
Endovascular Aneurysm Repair ◽  
Computational Cost ◽  
Element Analysis ◽  
Fea Model ◽  
Order Of Magnitude ◽  
Modelling Methodology ◽  
Computationally Intensive ◽  
Cfd Analyses

Abstract Numerical models of endografts for the simulation of endovascular aneurysm repair are increasingly important in the improvement of device designs and patient outcomes. Nevertheless, current finite element analysis (FEA) models of complete endograft devices come at a high computational cost, requiring days of runtime, therefore restricting their applicability. In the current study, an efficient FEA model of the Anaconda™ endograft (Terumo Aortic, UK) was developed, able to yield results in just over 4 h, an order of magnitude less than similar models found in the literature. The model was used to replicate a physical device that was deployed in a 3D printed aorta and comparison of the two shapes illustrated a less than 5 mm placement error of the model in the regions of interest, consistent with other more computationally intensive models in the literature. Furthermore, the final goal of the study was to utilize the deployed fabric model in a hemodynamic analysis that would incorporate realistic fabric folds, a feature that is almost always omitted in similar simulations. By successfully exporting the deployed graft geometry into a flow analysis, it was illustrated that the inclusion of fabric wrinkles enabled clinically significant flow patterns such as flow stagnation and recirculation to be detected, paving the way for this modelling methodology to be used in future for stent design optimisation.

Modelling Aspects in Accumulative Roll Bonding Process by Explicit Finite Element Analysis

2013 ◽  
Vol 549 ◽  
pp. 452-459 ◽  
Author(s):  
Livan Fratini ◽  
Marion Merklein ◽  
Wolfgang Böhm ◽  
Davide Campanella
Keyword(s):  
Accumulative Roll Bonding ◽  
Research Work ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Roll Bonding ◽  
Explicit Finite Element Analysis ◽  
Proposed Model ◽  
Time Minimization ◽  
2D And 3D ◽  
The Impact

Accumulative Roll-Bonding (ARB) process is a severe plastic deformation (SPD) process, capable of developing grains below 1 μm in diameter and improving mechanical properties of the material. In this study, the authors compared two different FE-codes with respect of its applicability for numerical analysis of the ARB process. Modelling this process was achieved using the explicit code for Abaqus/CAE both in 2D and 3D. The proposed model was used to assess the impact of ARB cycles on the final material properties. The numerical results in 2D and 3D were compared and contrasted. The research work presented in this paper is focused on the simulation optimization based on CPU time minimization. The numerical simulations were also validated through a comparison with the experimental results.

Characterization of Distorted Fluid Flow Along Advanced High-Bypass Jet Engine Subjected to Foreign Object Ingestion

2017 ◽  
Author(s):  
Yangkun Song ◽  
Javid Bayandor
Keyword(s):  
Finite Element ◽  
Progressive Failure ◽  
Element Formulation ◽  
Foreign Object ◽  
Arbitrary Lagrangian Eulerian ◽  
Element Analysis ◽  
Jet Engine ◽  
Explicit Finite Element ◽  
Modeling Methodology ◽  
Explicit Finite Element Analysis

In this study, a non-linear fluid-solid interaction (FSI) methodology is uniquely developed to simulate the aerodynamic interaction and disturbance of flow along a high-bypass propulsion system subjected to foreign object ingestion (FOI). For the analysis, a time explicit finite element analysis is applied with an advanced computational scheme, Arbitrary Lagrangian-Eulerian (ALE). The advanced finite element formulation is able to successfully demonstrate the interaction between air and the high-bypass jet engine subjected to a soft body FOI by solving both solid and fluid continua simultaneously. As a result, the proposed damage modeling methodology simulates the progressive failure caused by the exertion of aerodynamics over the damaged and undamaged components.

Finite Element Analysis of Contact Force Models During Solid Elastic and Plastic Bodies Impact

2018 ◽  
Author(s):  
Gustavo Simão Rodrigues ◽  
Hans Ingo Weber ◽  
Larissa Driemeier
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Force ◽  
Numerical Models ◽  
Element Model ◽  
The Body ◽  
Element Analysis ◽  
Solid Bodies ◽  
The Impact ◽  
Element Method

There are many models of impact used to predict the post-impact conditions of a system and all of them are based on Hertz’s theory, dated from the nineteenth century, where the repulsive force is proportional to the deformation of the bodies under contact and may also be proportional to the rate of deformation. The objective of this work is to analyze the behavior of the bodies during impact using some contact models and compare the results to a Finite Element Method model. The main parameters which will be evaluated are the body velocities, the contact force and the deformation of the bodies. An advantage of using the Finite Element Method is the possibility to apply plastic deformation to the model according to material definition. In the present study, it will be used Johnson–Cook plasticity model where the parameters are obtained based on empirical tests of real materials. Thus, it is possible to compare the behavior of elastic and plastic numerical models with the finite element model and to verify how these models reproduce the impact between solid bodies.

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