Low velocity impact fatigue studies on hybrid composite laminates with varied material and test parameters – effect of impact energy and fibre volume fraction

2011 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
K. Mohamed Kaleemulla ◽  
B. Siddeswarappa
Keyword(s):  
Impact Energy ◽  
Composite Laminates ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Low Velocity Impact ◽  
Impact Fatigue ◽  
Low Velocity ◽  
Velocity Impact ◽  
Test Parameters

Experimental Research on the Low Velocity Impact Damage of CCF300/QY8911 Composite Laminates

2012 ◽  
Vol 583 ◽  
pp. 179-182
Author(s):  
Hai Ming Hong ◽  
Ming Li ◽  
Jian Yu Zhang ◽  
Yi Ning Zhang
Keyword(s):  
Impact Energy ◽  
Composite Laminates ◽  
Low Velocity Impact ◽  
Test Machine ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Pattern ◽  
The Impact ◽  
Dent Depth ◽  
Delamination Damage

A group of low-velocity impact tests on CCF300/QY8911 composite laminates were implemented by the low-velocity drop hammer test machine. The dent depth and the internal damage pattern with corresponding impact energy were studied, the internal delamination damage state of laminates after impact were observed through thermal layer exposing tests, and the mechanism of low-velocity impact delamination damage were discussed. The results indicated that there existed a significant inflection point in the curve of impact energy verse dent depth of CCF300/QY8911 composite material, which was also the transition point of different damage patterns. When the impact energy was smaller than the inflection energy, the damage pattern consisted mainly of matrix flaws and delamination damages, but when the impact exceeded the inflection energy, delamination damage hardly expanded while the expansion of damage was mainly fiber break.

Bridging the low-velocity impact energy versus impact damage and residual compression strength for composite laminates

2020 ◽  
pp. 073168442097064
Author(s):  
Di Zhang ◽  
Xitao Zheng ◽  
Jin Zhou ◽  
Wenxuan Zhang
Keyword(s):  
Impact Energy ◽  
Composite Laminates ◽  
Damage Model ◽  
Low Velocity Impact ◽  
Fe Model ◽  
Material System ◽  
Cohesive Elements ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Area

A finite element (FE) model based on fiber kinking and a transversal fracture angle damage model with cohesive elements are proposed to simulate the low-velocity impact (LVI) and compression after impact (CAI), and build a relationship between LVI energy and CAI strength of composites. The proposed FE model is validated by a comprehensive experimental work conducted using a high strength carbon fiber/epoxy material system i.e. CCF300/BA9916II and underwent LVI and CAI experimentation.  The relative errors between numerical and experimental results of LVI damage area, maximum impact force, impact time, as well as CAI strength are less than 5%. The FE analysis results of LVI show that the dominant damage mode is delamination, and the CAI results demonstrate a brittle behavior with almost no loss of stiffness before failure. It is further deduced that the relationship of LVI energy and damage induced is directly proportional initially; however, after a threshold level of impact energy, the curve turns horizontal so that the increase in further impact energy does not increase the damage area substantially. A similar relationship is developed between impact energy and CAI strength.

scholarly journals Experimental and Simulation Study of Low-Velocity Impact on Glass Fiber Composite Laminates with Reinforcing Shape Memory Alloys at Different Layer Positions

2018 ◽  
Vol 8 (12) ◽  
pp. 2405 ◽  
Author(s):  
Min Sun ◽  
Mengzhou Chang ◽  
Zhenqing Wang ◽  
Hao Li ◽  
Xiaokun Sun
Keyword(s):  
Shape Memory ◽  
Impact Energy ◽  
Composite Laminates ◽  
Resin Composite ◽  
Glass Fibers ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Epoxy Resin Composite ◽  
Impact Damages

The effects of shape memory alloy (SMA) wires on the damage behavior of glass fibers/epoxy resin composite laminates for the case of low-velocity impact are investigated experimentally and numerically. In this work, the low-velocity impact tests of SMAs/glass fibers/epoxy resin composite laminates are carried out. The elastic–plastic theory was adopted to simulate the mechanical behavior of SMA during the loading stage. The three-dimensional (3D) Hashin failure criterion is adopted in Abaqus/Explicit to model the damage initiation of composite laminates. The cohesive damage model is introduced to control the interface element and model the delamination failure. Moreover, the impact damage mechanisms of composite laminates are analyzed based on the experimental and numerical simulation results. These results show that the numerical results obtained in the present study have a reasonably good agreement with the experimental results. In addition, it is also found that impact damages are mainly caused by matrix cracks and delamination with no perforation for the case of 32-J impact energy, and impact damages are mainly caused by fibers breakage with perforation for the case of 64-J impact energy.

Influence of patch lay-up configuration and hybridization on low velocity impact and post-impact tensile response of repaired glass fiber reinforced plastic composites

2018 ◽  
Vol 53 (1) ◽  
pp. 3-17 ◽  
Author(s):  
J Jefferson Andrew ◽  
Sivakumar M Srinivasan ◽  
A Arockiarajan
Keyword(s):  
Glass Fiber ◽  
Impact Energy ◽  
Volume Fraction ◽  
Glass Fibers ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Static Tensile ◽  
The Impact

This paper aims to investigate the effect of homogenous and hybrid external patches based on plain weave woven glass and Kevlar fabric on low velocity impact and quasi-static tensile after impact response of adhesively bonded external patch repairs in damaged glass/epoxy composite laminates. In all hybrid patches, the proportion of Kevlar and glass fibers were equal (i.e. 50% of Kevlar and 50% of glass by volume fraction), while lay-up configuration was different. This further enables to study the associated effect of hybridization and lay-up configuration on impact response of the repaired laminates. The intent of using hybrid external patches is to combine the excellent high displacement-to-failure property of Kevlar fiber as a ductile reinforcement with the superior mechanical property of glass fiber as a brittle reinforcement. The effect of glass/Kevlar content on impact response and tensile after impact response was investigated for various incident impact energy levels, such as 2, 4, 6, and 8 J. Results showed that hybridization and lay-up configurations of the external patches played a significant role on low velocity impact and quasi-static tensile after impact response of the repaired glass/epoxy specimens. Specimens repaired using intra-ply hybrid patches showed better impact properties and damage tolerance capability than that of the virgin and other repaired specimens. In specific, the use of intra-ply hybrid patches reduced the impact energy absorption by 10.17% in comparison to the virgin specimens at impact energy of 8 J.

scholarly journals Low Velocity Impact Energy Monitoring and Recognition of Composite Laminates with Variable Thickness Based on Optical Fiber Sensor Network

2021 ◽  
Vol 11 (2) ◽  
pp. 584
Author(s):  
Guan Lu ◽  
Tianyu Zhu ◽  
Yiming Xu
Keyword(s):  
Optical Fiber ◽  
Impact Energy ◽  
Variable Thickness ◽  
Composite Laminates ◽  
Optical Fiber Sensor ◽  
Low Velocity Impact ◽  
Average Error ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

At present, most of the research on low velocity impact of composite laminates focuses on load location and damage assessment. To provide further early warnings about structural impact damage, impact energy can be monitored and identified. For high strength composite laminates with variable thickness, in order to further accurately evaluate the impact energy, it is necessary to adopt more suitable dynamic load signal analysis and impact energy identification methods. Therefore, a new low velocity impact monitoring and identification method for composite plates with variable thickness is proposed. All impact sample signals collected by optical fiber sensor network are decomposed by whitening Empirical Mode Decomposition (EMD); the energy feature set is established according to the impact energy eigenvalue of sample signal; according to the first order component of signal decomposition, the thickness coefficient is determined and the energy feature set is modified to evaluate the actual impact energy. Meanwhile, combined with optical fiber sensing and signal processing technology, an impact energy monitoring system has been established, and the low velocity impact monitoring and identification experiments of composite laminates with variable thickness were carried out. The proposed energy identification method successfully identified 1–3 J impact energy with an average error of 4.82%, and the average error of large thickness area with low sensitivity was significantly reduced from 13.25% to 5.67%. The results show that the thickness coefficient correction method based on whitening EMD can evaluate the low velocity impact energy more accurately, and the thickness coefficient correction step significantly improves the recognition performance.

Response and failure modes of biaxial warp-knitted flexible composite subject to low-velocity impact

2021 ◽  
pp. 152808372110154
Author(s):  
Ziyu Zhao ◽  
Tianming Liu ◽  
Pibo Ma
Keyword(s):  
Impact Energy ◽  
Linear Density ◽  
Failure Modes ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Minor Effect ◽  
Low Velocity ◽  
Velocity Impact ◽  
Flexible Composites ◽  
The Impact

In this paper, biaxial warp-knitted fabrics were produced with different high tenacity polyester linear density and inserted yarns density. The low-velocity impact property of flexible composites made of polyurethane as matrix and biaxial warp-knitted fabric as reinforcement has been investigated. The effect of impactor shape and initial impact energy on the impact response of flexible composite is tested. The results show that the initial impact energy have minor effect on the impact response of the biaxial warp-knitted flexible composites. The impact resistance of flexible composite specimen increases with the increase of high tenacity polyester linear density and inserted yarns density. The damage morphology of flexible composite materials is completely different under different impactor shapes. The findings have theoretical and practical significance for the applications of biaxial warp-knitted flexible composite.

Effect of fibre content on the mechanical properties of hemp fibre woven fabrics/polypropylene composite laminates

2021 ◽  
pp. 096739112110239
Author(s):  
Sheedev Antony ◽  
Abel Cherouat ◽  
Guillaume Montay
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Composite Laminates ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Woven Fabrics ◽  
Fibre Content ◽  
Viscoelastic Behaviour ◽  
Hemp Fibre

Nowadays natural fibre composites have gained great significance as reinforcements in polymer matrix composites. Composite material based on a polymer matrix reinforced with natural fibres is extensively used in industry due to their biodegradability, recyclability, low density and high specific properties. A study has been carried out here to investigate the fibre volume fraction effect of hemp fibre woven fabrics/PolyPropylene (PP) composite laminates on the tensile properties and impact hammer impact test. Initially, composite sheets were fabricated by the thermal-compression process with desired number of fabric layers to obtain composite laminates with different fibre volume fraction. Uniaxial, shear and biaxial tensile tests were performed and mechanical properties were calculated. Impact hammer test was also carried out to estimate the frequency and damping parameters of stratified composite plates. Scanning Electron Microscope (SEM) analysis was performed to observe the matrix and fibre constituent defects. Hemp fabrics/PP composite laminates exhibits viscoelastic behaviour and as the fibre volume fraction increases, the viscoelastic behaviour decreases to elastic behaviour. Due to this, the tensile strength increases as the fibre content increases. On the other hand, the natural frequency increases and damping ratio decrease as the fibre volume fraction increases.

Sign in / Sign up

Export Citation Format

Share Document