scholarly journals Impact Behaviour of Glass Fribre /Epoxy Composites with Nano-Enhanced Resin after Water Exposure

2015 ◽  
Vol 15 (2) ◽  
pp. 30-35 ◽  
Author(s):  
M. Landowski ◽  
K. Imielińska
Keyword(s):  
Failure Modes ◽  
Impact Load ◽  
Impact Damage ◽  
Epoxy Composites ◽  
Low Velocity Impact ◽  
Absorption Mechanism ◽  
Impact Behaviour ◽  
Fibre Fracture ◽  
Water Exposure ◽  
Matrix Cracks

Abstract Impact behaviour of glass fibre /epoxy composites with nano- SiO2 modified resin was studied in terms of low velocity impact after water exposure. Nanocomposites with 1%, 2%, 3% 5% 7% nano-SiO2 (Nanopox- Evonic) were investigated. Peak impact load and impact damage area as a function of nanoparticle contents were compared for dry specimens and for samples exposed to water (0.7 %wt. 1.7% water absorbed) at 1J, 2J 3J impact energies. For unmodified composite peak force was higher than for 3% modified specimens and higher for dry specimens than those exposed to water. Impact damage areas were plotted as a function of water contents for modified and unmodified samples. Failure modes were illustrated using SEM micrographs. Numeropus matrix cracks were the dominating failure mode in dry speciemens both unmodified and the modified. Fibre fracture was observed at 3J impact energy in all dry unmodified samples, however water exposure prevented early fibre fracture in nanocomposites. The proposed energy absorption mechanism is nanoparticles debonding.

Predicting low-velocity impact damage in composites by a quasi-static load model with cohesive interface elements

2012 ◽  
Vol 116 (1186) ◽  
pp. 1367-1381 ◽  
Author(s):  
X. Zhang ◽  
F. Bianchi ◽  
H. Liu
Keyword(s):  
Impact Load ◽  
Impact Damage ◽  
Computational Effort ◽  
Low Velocity Impact ◽  
Cohesive Failure ◽  
Low Velocity ◽  
Element Analysis ◽  
Interface Elements ◽  
Velocity Impact ◽  
Matrix Cracks

AbstractA numerical model is developed for predicting low-velocity impact damage in laminated composites. Stacked shell elements are employed to model laminate plies with discrete interface elements in pre-determined zones to model the onset and propagation of matrix cracks and delamination. These interface elements are governed by a bi-linear cohesive failure law. Cohesive element zone size is determined by a separate finite element analysis using solid elements to identify the stress concentration sites. In order to save the computational effort, low-velocity impact load is modelled by quasi-static loading. Influence of contact force induced friction on shear driven mode II delamination is modelled by a friction model. For a clustered cross-ply laminate, calculated impact force and damage area are in good agreement with the test results. It is shown that matrix cracks should be included in the model in order to simulate delamination in adjacent interface. The practical outcome of this research is a validated modelling approach that can be further improved for predicting low-velocity impact damage in other stacking sequences.

Low Velocity Impact on Fiber Reinforced Geocomposites

2016 ◽  
Vol 827 ◽  
pp. 145-148 ◽  
Author(s):  
Sneha Samal ◽  
David Reichmann ◽  
Iva Petrikova ◽  
Bohdana Marvalova
Keyword(s):  
Impact Damage ◽  
Acoustic Vibration ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Behaviour ◽  
Reinforced Composite ◽  
Before And After ◽  
Two Parameters ◽  
The Impact

Low velocity impact strength of the fabric reinforced geocomposite has investigated in this article. Various fabrics such as carbon and E-glass were considered for reinforcement in geopolymer matrix. The primary two parameters such as low velocity, impact damage modes are explained on the E-glass and carbon based fabric geocomposite. The onset mode of damage to failure mode is examined through C-scan analysis. The quality of the composite is observed using c-scan with acoustic vibration mode of sensor before and after impact test. Then the effect of fabric and matrix on the impact behaviour is discussed. Residual strength of the composite is measured to determine post impact behaviour. It has been observed that resistance properties of E-glass reinforced composite is better than carbon fabric reinforced composite.

scholarly journals Mechanical Characterization and Impact Damage Assessment of Hybrid Three-Dimensional Five-Directional Composites

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1395 ◽  
Author(s):  
Liwei Wu ◽  
Wei Wang ◽  
Qian Jiang ◽  
Chunjie Xiang ◽  
Ching-Wen Lou
Keyword(s):  
Carbon Fiber ◽  
Impact Load ◽  
Hybrid Composites ◽  
Impact Damage ◽  
Three Dimensional ◽  
Low Velocity Impact ◽  
Aramid Fibers ◽  
Braided Composites ◽  
Low Velocity ◽  
Velocity Impact

The effects of braided architecture and co-braided hybrid structure on low-velocity response of carbon-aramid hybrid three-dimensional five-directional (3D5d) braided composites were experimentally investigated in this study. Low-velocity impact was conducted on two types of hybridization and one pure carbon fiber braided reinforced composites under three velocities. Damage morphologies after low-velocity impact were detected by microscopy and ultrasonic nondestructive testing. Interior damages of composites were highly dependent on yarn type and alignment. Impact damage tolerance was introduced to evaluate the ductility of hybrid composites. Maximum impact load and toughness changed with impact velocity and constituent materials of the composites. The composite with aramid fiber as axial yarn and carbon fiber as braiding yarn showed the best impact resistance due to the synergistic effect of both materials. Wavelet transform was applied in frequency and time domain analyses to reflect the failure mode and mechanism of hybrid 3D5d braided composites. Aramid fibers were used either as axial yarns or braiding yarns, aiding in the effective decrease in the level of initial damage. In particular, when used as axial yarns, aramid fibers effectively mitigate the level of damage during damage evolution.

Self-healing of low-velocity impact damage in glass fabric/epoxy composites using an epoxy–mercaptan healing agent

2010 ◽  
Vol 20 (1) ◽  
pp. 015024 ◽  
Author(s):  
Yan Chao Yuan ◽  
Yueping Ye ◽  
Min Zhi Rong ◽  
Haibin Chen ◽  
Jingshen Wu ◽  
...  
Keyword(s):  
Impact Damage ◽  
Epoxy Composites ◽  
Low Velocity Impact ◽  
Glass Fabric ◽  
Self Healing ◽  
Low Velocity ◽  
Velocity Impact ◽  
Healing Agent

Fatigue Behavior of Impacted Plain-Weave Glass/Epoxy Composites under Tensile Fatigue Loading

2005 ◽  
Vol 297-300 ◽  
pp. 1291-1296 ◽  
Author(s):  
Ki Weon Kang ◽  
Jung Kyu Kim ◽  
Heung Seob Kim
Keyword(s):  
Fatigue Life ◽  
Impact Damage ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Epoxy Composites ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Behavior ◽  
Plain Weave ◽  
The Impact

The goals of this paper are to identify the impact damage behavior of plain-weave E-glass/epoxy composites and predict the fatigue life of the composites with impact-induced damage under constant amplitude loading. To identify these behaviors, the low velocity impact and fatigue after impact tests are performed for glass/epoxy composites having two types of fiber orientations. The impact damage behavior is dependent on the fiber orientation of the composites. The fatigue life of the impacted composites can be identified through the prediction model, which was proposed on the carbon/epoxy laminates by authors regardless of fiber orientations.

Study on damage behavior of carbide tool for milling difficult-to-machine material

2018 ◽  
Vol 233 (2) ◽  
pp. 735-747
Author(s):  
Yao-Nan Cheng ◽  
Wan-Ying Nie ◽  
Rui Guan ◽  
Wei-Kun Jia ◽  
Fu-gang Yan
Keyword(s):  
Failure Modes ◽  
Impact Load ◽  
Impact Damage ◽  
High Plasticity ◽  
Carbide Tool ◽  
Machine Material ◽  
Tool Failure ◽  
Damage Behavior ◽  
Tool Damage ◽  
The Impact

Water chamber head is an important component of nuclear power unit, and the main material is 508 III steel of difficult-to-machine material, which has the characteristics of high hardness, high strength, high plasticity and high profile shrinkage, etc. During the milling process, the tool is subjected to the cyclic impact load, which make cutting force and cutting heat change violent and occurrence of tool damage failure accelerate. In this paper, the damage behavior of carbide tool for milling difficult-to-machine material is studied first, and then field experiment was carried out on 508 III steel material, tool failure modes were analyzed, which include impact damage and fatigue fracture, and the failure theory and the crack propagation of carbide material were investigated in the process of tool damage. Then, the impact damage model of carbide tool is established based on the classical strength theory, and the critical condition of impact damage is determined according to simulation analysis. Finally, the theoretical model of carbide tool fatigue life is established and the tool fatigue limit is analyzed. Theoretical basis and technical support are provided for the tool failure mechanisms analysis, life prediction, parameter optimization, tool design and development aspects during the study.

Compression after impact behavior of titanium honeycomb sandwich structures

2017 ◽  
Vol 20 (5) ◽  
pp. 639-657 ◽  
Author(s):  
Wei Zhao ◽  
Zonghong Xie ◽  
Xiang Li ◽  
Xishan Yue ◽  
Junfeng Sun
Keyword(s):  
Failure Modes ◽  
Sandwich Structures ◽  
Impact Damage ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Failure Strength ◽  
Compressive Failure ◽  
Low Velocity ◽  
Honeycomb Sandwich

Titanium honeycomb sandwich structures are gradually used in several newly developed aircrafts in China. During the manufacturing process and aircraft service life, low-velocity impacts from foreign objects (typically stones, tools and hails, etc.), would quite likely happen and could not be completely avoided. In order to evaluate the influence of low-velocity impact damage on titanium honeycomb sandwich structures, unidirectional in-plane compression tests on both intact and impact damaged sandwich panels were conducted to obtain their failure modes and compressive failure strength. Test results showed that the low-velocity impact damage could cause the change in failure modes and a 9% to 15% decrease in the compressive failure strength. Different impact energy levels showed a limited influence on the compressive failure strength. Numerical analysis was conducted to study the compression after impact behavior of titanium sandwich panels. Parametric finite element models that contained all the geometric and the structural details of honeycomb core cells, as well as the indentation and the crushed core region, were developed in the analysis. The numerical results successfully exhibited the failure process of the intact and impact damaged titanium sandwich panels subjected to unidirectional in-plane compression, similar to what observed in the tests. The predicted compressive failure strength also agreed very well with the test data.

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.

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