scholarly journals Falling Weight Impact Damage Characterisation of Flax and Flax Basalt Vinyl Ester Hybrid Composites

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 806 ◽  
Author(s):  
Hom Nath Dhakal ◽  
Elwan Le Méner ◽  
Marc Feldner ◽  
Chulin Jiang ◽  
Zhongyi Zhang
Keyword(s):  
Vinyl Ester ◽  
Failure Modes ◽  
Hybrid Composites ◽  
Impact Damage ◽  
Matrix Cracking ◽  
Damage Mechanisms ◽  
Pull Out ◽  
Weight Impact ◽  
Falling Weight ◽  
The Impact

Understanding the damage mechanisms of composite materials requires detailed mapping of the failure behaviour using reliable techniques. This research focuses on an evaluation of the low-velocity falling weight impact damage behaviour of flax-basalt/vinyl ester (VE) hybrid composites. Incident impact energies under three different energy levels (50, 60, and 70 Joules) were employed to cause complete perforation in order to characterise different impact damage parameters, such as energy absorption characteristics, and damage modes and mechanisms. In addition, the water absorption behaviour of flax and flax basalt hybrid composites and its effects on the impact damage performance were also investigated. All the samples subjected to different incident energies were characterised using non-destructive techniques, such as scanning electron microscopy (SEM) and X-ray computed micro-tomography (πCT), to assess the damage mechanisms of studied flax/VE and flax/basalt/VE hybrid composites. The experimental results showed that the basalt hybrid system had a high impact energy and peak load compared to the flax/VE composite without hybridisation, indicating that a hybrid approach is a promising strategy for enhancing the toughness properties of natural fibre composites. The πCT and SEM images revealed that the failure modes observed for flax and flax basalt hybrid composites were a combination of matrix cracking, delamination, fibre breakage, and fibre pull out.

scholarly journals 3D Progressive Failure Modeling of Drop-Weight Impact on Composite Laminates

2018 ◽  
Author(s):  
DC Pham
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Progressive Failure ◽  
Damage Model ◽  
Matrix Cracking ◽  
Structural Level ◽  
Velocity Impact ◽  
Drop Weight ◽  
Weight Impact ◽  
The Impact

Composite laminates are susceptible to out-of-plane impact loads due to the lack of reinforcement in the through-thickness direction. Unlike the localized damage induced by a high velocity impact where the incident energy is dissipated near a contact area, low velocity impact damage involves multiple failure mechanisms such as matrix cracking, fiber breakage, and widespread interface delaminations. Depending on the extent of damage, significant reduction in the load-bearing capability of the structure has been observed. The prediction of composite impact damage resistance by a reliable progressive damage analysis tool is essential to reduce intensive and expensive certification tests at structural level. In this work, an enhanced explicit 3D damage model is implemented via VUMAT in Abaqus to perform a drop-weight impact simulation of a [454/04/-454/904]s Hexply AS4/8552 composite laminate. The impact-induced damage and its extent are captured by a 3D Continuum Damage Model (CDM) coupled with an energy driven failure mechanism. The developed module provides a unified solution process for the impact response prediction followed by the residual strength prediction under compression within an explicit solver. Two examples are selected to demonstrate the capability of the progressive failure analysis under dynamic and static loading: 1) a drop-weight test; and 2) an open-hole tension test. Numerical predictions from the developed VUMAT are compared with the test data and predictions using the open source CompDam code developed by NASA.

A damage mechanics model for low-velocity impact damage analysis of composite laminates

2017 ◽  
Vol 121 (1238) ◽  
pp. 515-532 ◽  
Author(s):  
N. Li ◽  
P.H. Chen ◽  
Q. Ye
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Impact Damage ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Fracture Plane ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

ABSTRACTA method was developed to predict numerically the damage of composite laminates with multiple plies under low-velocity impact loading. The Puck criterion for 3D stress states was adopted to model the intralaminar damage including matrix cracking and fibre breakage, and to obtain the orientation of the fracture plane due to matrix failure. According to interlaminar delamination mechanism, a new delamination criterion was proposed. The influence of transverse and through-thickness normal stress, interlaminar shear stress and damage conditions of adjacent plies on delamination was considered. In order to predict the impact-induced damage of composite laminates with more plies quickly and efficiently, an approach, which can predict the specific damage of several plies in a single solid element, was proposed by interpolation on the strains of element integration points. Moreover, the proposed model can predict specific failure modes. A good agreement between the predicted delamination shapes and sizes and the experimental results shows correctness of the developed numerical method for predicting low-velocity impact damage on composite laminates.

Peridynamic modeling of low-velocity impact damage in laminated composites reinforced with z-pins

2018 ◽  
Vol 52 (25) ◽  
pp. 3491-3508 ◽  
Author(s):  
Forrest Baber ◽  
Vipul Ranatunga ◽  
Ibrahim Guven
Keyword(s):  
Failure Modes ◽  
Impact Damage ◽  
Impact Testing ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Identification Algorithm ◽  
Low Velocity ◽  
New Approach ◽  
Velocity Impact ◽  
The Impact

In this study, a new approach for predicting damage and specific failure modes in laminated fiber reinforced composites is presented. The new method is based on the peridynamic theory and models individual plies, and represents fiber and matrix materials in each ply explicitly. These features enable analysis of laminates with arbitrary fiber orientation in a convenient manner. Additionally, a new failure mode identification algorithm has been developed and implemented. Instead of the conventional peridynamic damage parameter, the new algorithm works with individual broken bonds, which makes identification of different failure modes including matrix cracking, fiber breakage, and delamination straight-forward and unambiguous. The new peridynamic approach is demonstrated by considering the low-velocity impact damage on composite laminates with and without translaminar reinforcements. The translaminar reinforcement technique considered in this study is z-pinning; two different geometric configurations of z-pins are explored. The impact testing and the post-impact nondestructive evaluations with ultrasonic c-scans are performed at the Air Force Research Laboratory to characterize the delaminations. The impact tests on different samples are simulated using the current peridynamic approach. The predicted impact damage failure modes are compared against the experimental measurements. The new approach is shown to capture low-velocity impact damage both quantitatively and qualitatively.

Impact Tension Damage Mechanism Analyses of Co-Woven-Knitted Composite from Hilbert–Huang Transform

2011 ◽  
Vol 21 (4) ◽  
pp. 493-523 ◽  
Author(s):  
Pibo Ma ◽  
Baozhong Sun ◽  
Bohong Gu
Keyword(s):  
Strain Rate ◽  
Failure Modes ◽  
Damage Mechanism ◽  
Strain Rates ◽  
Damage Mechanisms ◽  
Frequency Distributions ◽  
Hilbert Huang Transform ◽  
Pull Out ◽  
Impact Tension ◽  
The Impact

The impact tensile behaviors of co-woven-knitted (CWK) composites were tested with split Hopkinson tension bar apparatus along 0°, 45°, and 90° directions under the strain rates from 1589 to 2586 s−1 and compared with that in quasi-static strain rate of 0.001 s−1. The impact tension damage mechanisms were analyzed in frequency domain with the Hibert–Huang transform (HHT) method. Specifically, the stress time histories curves of the CWK composite were transformed to find the frequency distributions for the different tension failure modes. It was found that thefailure mode of fiber breakages, fiber pull-out, resin cracks, and resin shear failurewere located at a specific frequency band. And also, the different failure modes under high strain rate loading are all located at the high frequency range. With such kind of HHT analyses, the damage mechanisms could be explored more precisely when combined with the observation results of the fractographs of the CWK composite under various strain rates.

Ballistic Impact Testing and Analysis of Triaxial Braided Composite Fan Case Material

2012 ◽  
Vol 535-537 ◽  
pp. 121-132
Author(s):  
Lu Lu Liu ◽  
Hai Jun Xuan ◽  
Guang Tao Chen ◽  
Dong Ye ◽  
Wei Rong Hong ◽  
...  
Keyword(s):  
Failure Modes ◽  
Ballistic Impact ◽  
Impact Testing ◽  
Matrix Cracking ◽  
Case Material ◽  
Absorption Mechanism ◽  
Penetration Process ◽  
Braided Composite ◽  
Pull Out ◽  
The Impact

Abstract. Ballistic impact tests were preformed on triaxial braided composite panels using blade-like projectile in a way that approximates the impact velocity, deformation modes, and strain energy density at failure for composite fan case material during blade-out event. The failure modes are identified from impact test results. The main failure modes are fiber shear failure and matrix crush failure in the impact surface and fiber tensile failure, fiber pull-out, matrix cracking and delamination in the exit surface. Finite element model is developed to analyze the damage evolution of penetration process. It is found that the penetration process can be subdivided into 3 stages based on different damage mechanisms and the energy absorption mechanism in each phase is illustrated too.

scholarly journals Influence of Water Absorption on the Low Velocity Falling Weight Impact Damage Behaviour of Flax/Glass Reinforced Vinyl Ester Hybrid Composites

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 278 ◽  
Author(s):  
Angeline Paturel ◽  
Hom Nath Dhakal
Keyword(s):  
Glass Fibre ◽  
Vinyl Ester ◽  
Room Temperature ◽  
Moisture Absorption ◽  
Impact Damage ◽  
Flax Fibre ◽  
Low Velocity ◽  
Glass Fibre Reinforced ◽  
Weight Impact ◽  
Falling Weight

Due to rigorous new environmental legislations, automotive, marine, aerospace, and construction sectors have redirected their focus into using more recyclable, sustainable, and environmentally friendly lightweight materials driven by strengthening resource efficiency drive. In this study, the influence of moisture absorption on flax and flax/glass hybrid laminates is presented with the aim to investigating their low velocity impact behaviour. Three different types of composite laminates namely, flax fibre reinforced vinyl ester, flax fibre hybridised glass fibre and glass fibre reinforced vinyl ester composites were fabricated using resin infusion technique. The moisture immersion tests were undertaken by immersing the different specimens in sea water bath at room temperature and 70 °C at different time durations. The low velocity falling weight impact testing was performed at 25 Joules of incident energy level and impact damage behaviour was evaluated at both ageing conditions using scanning electron microscopy (SEM) and X-ray microcomputed tomography (micro CT). The percentage of moisture uptake was decreased for flax vinyl ester specimens with glass fibre hybridisation. The maximum percentage of weight gain for flax fibre, flax/glass hybrid and glass fibre reinforced composites immersed at room temperature for 696 h is recorded at 3.97%, 1.93%, and 0.431%, respectively. The hybrid composite exhibited higher load and energy when compared flax/vinyl ester composite without hybridisation, indicating the hybrid system as a valid strategy towards achieving improved structural performance of natural fibre composites. The moisture absorption behaviour of these composites at room was observed to follow Fickian behaviour.

Damage Development in CFRP Laminates under Impact Loading

2006 ◽  
Vol 326-328 ◽  
pp. 1833-1836 ◽  
Author(s):  
Seung Min Jang ◽  
Tadaharu Adachi ◽  
Akihiko Yamaji
Keyword(s):  
Impact Damage ◽  
Stacking Sequence ◽  
Absorbed Energy ◽  
Damage Development ◽  
Damage Resistance ◽  
Cfrp Laminates ◽  
Impact Tester ◽  
Weight Impact ◽  
The Impact ◽  
Delamination Area

The development characteristics of impact-induced damage in carbon-fiber-reinforcedplastics (CFRP) laminates were experimentally studied using a drop-weight impact tester. Five types of CFRP laminates were used to investigate the effect of stacking sequences and thicknesses. The efficiency of absorbed energy to impact energy was different for CFRP laminates with different stacking sequences or thicknesses. The DA/AE ratio of delamination area (DA) to absorbed energy (AE) was almost the same for CFRP laminates with the same stacking sequence regardless of the thickness. We found that the DA/AE ratio could be used as a parameter to characterize the impact damage resistance in CFRP laminates with different stacking sequences.

Influence of Hybridisation and Test Geometry on the Impact Response of Glass-Fibre-Reinforced Laminated Composites

2002 ◽  
Vol 10 (4) ◽  
pp. 259-272 ◽  
Author(s):  
Bernard Schrauwen ◽  
Pascal Bertens ◽  
Ton Peijs
Keyword(s):  
Glass Fibre ◽  
Test Set ◽  
Impact Behaviour ◽  
Impact Tests ◽  
Hybrid Laminates ◽  
Glass Fibre Reinforced ◽  
Weight Impact ◽  
Set Up ◽  
Falling Weight ◽  
The Impact

This paper describes the results of falling weight impact tests (FWITs) on glass-fibre-reinforced (GRP) laminates and E-glass/Dyneema® hybrid laminates. The test programme consisted of (i) falling weight impact tests to determine the penetration energy and (ii) experiments to determine the influence of hybrid construction on damage development and impact fatigue lifetime under repeated impact conditions at sub-penetration energy levels. The objective of this work was to investigate the effect of hybridisation on the impact behaviour of GRP laminates as well as to find optimal conditions for hybridisation. It was shown that in the case of a rigid test set-up - and hence small deflections - the influence of the Dyneema® on the impact behaviour of hybrid laminates is rather small because damage processes are the result of local contact stresses in the vicinity of the impact body, whereas in the case of a compliant test set-up and large deflections the high energy storage capacity of the ductile Dyneema® fibres is used far more effectively for the protection of hybrid composite laminates. Therefore, it was concluded that in order to fully utilise the potential of high-performance polyethylene fibres it is essential that these fibres are located on the (non-impacted) tensile side of an impacted laminate and that the geometrical test conditions are such that large (bending) deformations are allowed.

scholarly journals Detection and evaluation of barely visible impact damage in woven glass fabric reinforced polyamide 6.6/6 composite using ultrasonic imaging, X-ray tomography and optical profilometry

2020 ◽  
pp. 105678952095770
Author(s):  
N Miqoi ◽  
P Pomarede ◽  
F Meraghni ◽  
NF Declercq ◽  
L Guillaumat ◽  
...  
Keyword(s):  
Impact Loading ◽  
Impact Damage ◽  
Woven Fabric ◽  
Glass Fabric ◽  
Optical Profilometry ◽  
Damage Mechanisms ◽  
X Ray ◽  
Drop Weight ◽  
Weight Impact ◽  
Polyamide 6.6

The present experimental work investigates the response of woven glass fabric reinforced polyamide 6.6/6 subjected to drop weight impact loading. The main objective is the development and the introduction of a new experimental procedure/approach, based on different complementary detection techniques, that aims at investigating the damage induced by impact loading in thermoplastic woven fabric composites. The developed approach is intended to be generalized to other types of composite materials. The main idea is to assess all the experimental results obtained through the developed procedure with a direct investigation method. The latter consists in the Permanent Indentation (PI) measurement providing an indicator of the damage criticality in the composite sample. To this end, several non-destructive testing methods are carried-out and their experimental findings are analyzed and cross-linked. The identification of the different damage mechanisms, caused by the drop weight impact, is performed using X-Ray micro-computed tomography (µCT). C-scan ultrasonic investigation is conducted according to two types: transmission and reflection for the detection of the impact damage and the identification of the induced degradation area. B-scan imaging are then obtained through specific post-processing of the impacted surface to extract the permanent indentation (PI). The latter is validated through surface flatness measurement using the highly resolved 3D optical profilometry. The correlation between the X-Ray tomography results and the permanent indentation measurement is then established. It correlates the PI level with the damage mechanisms of a barely visible impact damage (BVID) in woven glass reinforced polyamide 6.6/6 composite.

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