The Influence of GI and GII on the compression after impact strength of carbon fiber/epoxy laminates

2017 ◽  
Vol 52 (8) ◽  
pp. 991-1003 ◽  
Author(s):  
Alan Tate Nettles ◽  
Luke Scharber
Keyword(s):  
Carbon Fiber ◽  
Impact Strength ◽  
Compression Strength ◽  
Epoxy Resins ◽  
Impact Damage ◽  
Compression After Impact ◽  
The Difference ◽  
Type Of Failure ◽  
Carbon Fiber Epoxy ◽  
Residual Compression

This study measured the compression after impact strength of IM7 carbon fiber laminates made from epoxy resins with various mode I and mode II toughness values to observe the effects of these toughness values on the resistance to damage formation and subsequent residual compression strength-carrying capabilities. A total of seven different epoxy resin systems were used ranging in approximate GI values of 245–665 J/m2 and approximate GII values of 840–2275 J/m2. The results for resistance to impact damage formation showed that there was a direct correlation between GII and the planar size of damage as measured by thermography. Subsequent residual compression strength testing suggested that GI had no influence on the measured values and most of the difference in compression strength was directly related to the size of damage. Thus, delamination growth assumed as an opening type of failure mechanism does not appear to be responsible for the loss of compression strength.

scholarly journals Impact Damage and Residual Compression Strength of CNF/CFRP Hybrid Laminates

2013 ◽  
Vol 7 (3) ◽  
pp. 381-393 ◽  
Author(s):  
Hiroaki ITO ◽  
Masahiro ARAI ◽  
Kenta TAKEYAMA ◽  
Ning HU ◽  
Marino QUARESIMIN
Keyword(s):  
Compression Strength ◽  
Impact Damage ◽  
Hybrid Laminates ◽  
Residual Compression

scholarly journals Curing Kinetics, Mechanical Properties and Thermomechanical Analysis of Carbon Fiber/epoxy Resin Laminates with Different Ply Orientations

2021 ◽  
Author(s):  
Chenglin Zhang ◽  
Guohua Gu ◽  
Shuhua Dong ◽  
Zhitao Lin ◽  
Chuncheng Wei ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Composite Laminates ◽  
Bending Strength ◽  
Fiber Composite ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
The Impact ◽  
Carbon Fiber Epoxy

Abstract In this study, the nonisothermal differential scanning calorimetry (DSC) was carried out to evaluate the curing reaction of fiber/epoxy laminates. The optimal curing process of the prepreg was obtained by T-β extrapolation method and nth-order reaction curing kinetic equation. The bending strength, impact strength and thermodynamic properties of the composite laminates with different ply orientations were investigated, respectively. The results show that the apparent activation energy and the reaction order of the prepregs are 82.89 kJ/mol and 0.92, respectively. The curing process of carbon fiber/epoxy resin prepreg is 130 ℃ /60min + 160 ℃/30 min. The bending strength of [0]10 laminate is 1948.3 MPa, which is 11.8 times higher than that of [+ 45/-45]5s laminate, and 96.4% higher than that of [0/90]5s laminate. The impact strength of [0]10 laminate is higher than that of [+ 45/-45]5s and [0/90]5s laminates. The glass transition temperature (Tg) of the laminates is 142 ~ 146 ℃, and the loss factor of [0]10 laminate is significantly higher than that of [+ 45/-45]5s and [0/90]5s laminates. This research provides a theoretical basis for the further application of prepregs to fiber composite materials.

scholarly journals On Simulation of Impact Damage in Composite Laminate

1995 ◽  
Vol 4 (1) ◽  
pp. 096369359500400
Author(s):  
Y. Xiong
Keyword(s):  
Impact Strength ◽  
Prediction Model ◽  
Stress Analysis ◽  
Variational Approach ◽  
Composite Laminate ◽  
Impact Damage ◽  
Finite Width ◽  
Compression After Impact ◽  
Soft Inclusion ◽  
The Impact

A complex variational approach is proposed for the stress analysis of a finite composite laminate containing soft inclusion of elliptical shape which simulates the impact damage. The finite width correction is avoided by using this approach in the prediction model for the compression-after-impact strength of laminates. Comparisons with the FEM and test date are made and presented to verify the accuracy of the approach proposed.

The influence of hybridization on impact damage behavior and residual compression strength of intraply basalt/nylon hybrid composites

2013 ◽  
Vol 43 ◽  
pp. 283-290 ◽  
Author(s):  
Majid Tehrani Dehkordi ◽  
Hooshang Nosraty ◽  
Mahmood Mehrdad Shokrieh ◽  
Giangiacomo Minak ◽  
Daniele Ghelli
Keyword(s):  
Compression Strength ◽  
Hybrid Composites ◽  
Impact Damage ◽  
Damage Behavior ◽  
Residual Compression

scholarly journals Evaluation of test methods and face-sheet thickness effects in damage tolerance assessment of composite sandwich plates

2021 ◽  
pp. 109963622110369
Author(s):  
Moeen S Rajput ◽  
Magnus Burman ◽  
Stefan Hallström
Keyword(s):  
Impact Strength ◽  
Impact Assessment ◽  
Impact Damage ◽  
Test Methods ◽  
Test Method ◽  
Face Sheet ◽  
Composite Sandwich ◽  
Compression After Impact ◽  
Post Impact ◽  
Impact Damages

Composite sandwich materials provide high bending performance-to-weight ratios. However, these materials are vulnerable to impact damages which can drastically reduce their load-bearing capability. Presently there is a lack of standardised test methods for impact assessment. This study compares three different test methods for impact assessment; single skin compression after impact (CAI-SS), sandwich compression after impact (CAI-SW) and four-point bending-after-impact (BAI). The CAI-SS test method shows high compressive strength and strain at failure and the tesr is relatively easy to evaluate. For finite size plates with significant impact damage, the CAI-SS test method is recommended for post impact strength assessment. For large sandwich panels with relatively small impact damages the CAI-SW test method could be more relevant since it includes effects of panel asymmetry generated from the impact damage. The BAI test method may be recommended as an alternative to CAI but quite long specimens are required in order to assure compressive failure in the tested face-sheet, making the test both demanding and expensive. On the other hand, lower load levels are required to break the specimens and there is less need for precise machining during specimen manufacturing. A finite element model including progressive damage evolution was used to estimate the post impact strength. The simulations showed generally good agreement with the experiments.

Study on the Low-Velocity Impact Behavior of CFRP with Nanoclay-Filled Epoxy Matrix

2008 ◽  
Vol 47-50 ◽  
pp. 1205-1208 ◽  
Author(s):  
Iqbal Kosar ◽  
Khan Shafi Ullah ◽  
Jang Kyo Kim ◽  
Arshad Munir
Keyword(s):  
Impact Damage ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Damage Resistance ◽  
Velocity Impact ◽  
Compression After Impact ◽  
The Impact ◽  
Carbon Fiber Epoxy ◽  
Insight Into

The influence of nanoclay on the impact damage resistance of carbon fiber-epoxy (CFRP) composites has been investigated using the low-velocity impact and compression after impact tests. The load-energy vs time relations were analyzed to gain insight into the damage behaviors of the materials. Compression-after-impact (CAI) test was performed to measure the residual compressive strength. The CFRPs containing organoclay brought about a significant improvement in impact damage resistance and damage tolerance. The composites containing organoclay exhibited an enhanced energy absorption capability with less damage areas and higher CAI strengths compared to those made from neat epoxy. A 3wt% phr was shown to be an optimal content with the highest damage resistance.

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