Charpy impact tests on composite structures – An experimental and numerical investigation

2008 ◽  
Vol 68 (12) ◽  
pp. 2391-2400 ◽  
Author(s):  
W. Hufenbach ◽  
F. Marques Ibraim ◽  
A. Langkamp ◽  
R. Böhm ◽  
A. Hornig
Keyword(s):  
Numerical Investigation ◽  
Composite Structures ◽  
Charpy Impact ◽  
Impact Tests

An experimental–numerical investigation of hydrothermal response in adhesively bonded composite structures

2015 ◽  
Vol 73 ◽  
pp. 176-185 ◽  
Author(s):  
Roohollah Sarfaraz ◽  
Luis P. Canal ◽  
Georgios Violakis ◽  
John Botsis ◽  
Véronique Michaud ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Composite Structures ◽  
Adhesively Bonded ◽  
Bonded Composite

scholarly journals Effect of Multi-Impact on QIQH Carbon/Epoxy Composite Laminate

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 511
Author(s):  
Adadé Seyth Ezéckiel Amouzou ◽  
Olivier Sicot ◽  
Ameur Chettah ◽  
Shahram Aivazzadeh
Keyword(s):  
Composite Structures ◽  
Epoxy Composite ◽  
Impact Damage ◽  
Ultrasonic Control ◽  
Impact Tests ◽  
Post Impact ◽  
Testing Techniques ◽  
Force Time ◽  
The Relationship ◽  
Force Displacement

This work is motivated by increasingly used of composite structures under severe loading conditions. During their use, these materials are often subjected to impact as for example, in the aeronautical field the fall of hailstone on structure composites. In fact, the low energy traditional impact tests don’t allow to see the evolution of the damage and don’t permit also to compare the best tolerance to impact between different stratifications. The multi-impact tests made it possible to find a solution to this problem. In this work, multi-impact tests are performed on three carbon/epoxy stratifications. The final goal is to predict the durability of the composite structures during impact loading for their design. This study brings to light the response of multi-impact tests through force-time and force-displacement curves obtained experimentally. On the other hand, a parameter D has introduced following the experimental results. This made it possible to rank the three stratifications from their tolerance to multi-impact tests. To evaluate the post impact damage, ultrasonic testing techniques are used. The results allow to find the relationship between the damaged surface obtained by the ultrasonic control and the parameter D and to rank the three laminates configurations.

Charpy Impact Tests of Polyester Composites Reinforced with Palf fibers

2016 ◽  
pp. 371-376
Author(s):  
Gabriel O. Glória ◽  
Giulio R. Altoé ◽  
Maycon A. Gomes ◽  
Carlos Maurício F. Vieira ◽  
Maria Carolina A. Teles ◽  
...  
Keyword(s):  
Charpy Impact ◽  
Impact Tests ◽  
Polyester Composites

scholarly journals Effect of Thermal Ageing on the Impact Damage Resistance and Tolerance of Carbon-Fibre-Reinforced Epoxy Laminates

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 160 ◽  
Author(s):  
Irene García-Moreno ◽  
Miguel Caminero ◽  
Gloria Rodríguez ◽  
Juan López-Cela
Keyword(s):  
Carbon Fibre ◽  
Residual Strength ◽  
Composite Structures ◽  
Impact Resistance ◽  
Thermal Ageing ◽  
Low Velocity Impact ◽  
Impact Tests ◽  
Compression After Impact ◽  
Structural Applications ◽  
The Impact

Composite structures are particularly vulnerable to impact, which drastically reduces their residual strength, in particular, at high temperatures. The glass-transition temperature (Tg) of a polymer is a critical factor that can modify the mechanical properties of the material, affecting its density, hardness and rigidity. In this work, the influence of thermal ageing on the low-velocity impact resistance and tolerance of composites is investigated by means of compression after impact (CAI) tests. Carbon-fibre-reinforced polymer (CFRP) laminates with a Tg of 195 °C were manufactured and subjected to thermal ageing treatments at 190 and 210 °C for 10 and 20 days. Drop-weight impact tests were carried out to determine the impact response of the different composite laminates. Compression after impact tests were performed in a non-standard CAI device in order to obtain the compression residual strength. Ultrasonic C-scanning of impacted samples were examined to assess the failure mechanisms of the different configurations as a function of temperature. It was observed that damage tolerance decreases as temperature increases. Nevertheless, a post-curing process was found at temperatures below the Tg that enhances the adhesion between matrix and fibres and improves the impact resistance. Finally, the results obtained demonstrate that temperature can cause significant changes to the impact behaviour of composites and must be taken to account when designing for structural applications.

scholarly journals Microstructure and Mechanical Properties Affecting Crack Growth Behaviour in AA6060 Produced by Equal-Channel Angular Extrusion

2008 ◽  
Vol 584-586 ◽  
pp. 815-820 ◽  
Author(s):  
Lothar W. Meyer ◽  
Kristin Sommer ◽  
T. Halle ◽  
Matthias Hockauf
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Fatigue Crack ◽  
Crack Propagation ◽  
Crack Growth ◽  
Charpy Impact ◽  
Coarse Grained ◽  
Growth Behaviour ◽  
Crack Growth Behaviour ◽  
Impact Tests

Crack growth in AA6060 after two and eight equal-channel angular extrusions (ECAE), showing a bimodal microstructure and a homogenous ultrafine-grained microstructure, respectively, are compared to the coarse grained counterpart. Furthermore, an optimized condition, obtained by combining one ECA-extrusion and a subsequent short aging treatment is included. Fatigue crack growth behaviour in the near-threshold regime and the region of stable crack growth is investigated and related to microstructural features such as grain size, grain size distribution, grain boundary characteristics and ductility. Micrographs of crack propagation surfaces reveal information on crack propagation features such as crack path deflection and give an insight to the underlying microstructure. Instrumented Charpy impact tests are performed to investigate crack initiation and propagation under impact conditions. Due to the recovery of ductility during the post-ECAE heat treatment, the optimized condition shows improved fatigue crack properties and higher energy consumption in Charpy impact tests, when compared to the as-processed conditions without heat treatment.

Transition Region of Nuclear Vessel Steels: Master Curve Approach Using Small Punch Notched Specimens

2017 ◽  
Vol 734 ◽  
pp. 77-86
Author(s):  
Roberto Lacalle ◽  
David Andrés ◽  
José Alberto Álvarez ◽  
Federico Gutiérrez-Solana
Keyword(s):  
Transition Region ◽  
Master Curve ◽  
Nuclear Reactor ◽  
Structural Integrity ◽  
Charpy Impact ◽  
Vessel Steel ◽  
New Approach ◽  
Small Punch ◽  
Impact Tests ◽  
Integrity Assessments

The behaviour of the materials in ductile-brittle transition region must be known when performing structural integrity assessments of nuclear reactor vessels working under the effects of neutron irradiation. The characterisation of this region has been usually carried out by means of Charpy impact tests. Just during last few years new approaches based on direct fracture mechanics tests have begun to be used. In most of these cases, the Master Curve methodology, which allows the transition region to be characterised using only one parameter (T0 reference temperature), has been employed. In this paper the transition region of two materials –one vessel steel and one common structural steel-has been characterised by means of Small Punch Tests. First of all, this zone has been characterised using conventional specimens and the results were compared with those of Charpy impact tests. Finally a new approach based on the use of notched Small Punch samples together with Master Curve methodology has been proposed.

Finite Element Modeling and Experimental Characterization of Enhanced Hybrid Composite Structures for Improved Crashworthiness

2013 ◽  
Vol 80 (5) ◽  
Author(s):  
Luciana Arronche ◽  
Israel Martínez ◽  
Valeria La Saponara ◽  
Elias Ledesma
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Hybrid Composite ◽  
Composite Structures ◽  
Testing Machine ◽  
Strain Curve ◽  
Qualitative Behavior ◽  
Fe Model ◽  
Impact Tests ◽  
Highly Nonlinear

In this work, two hybrid composite structures were designed, modeled, and tested for improved resistance to impact. They were inspired by bistable composite structures, which are structures composed of two parts: a so-called “main link” and a so-called “waiting link.” These links work together as a mechanism that will provide enhanced damage tolerance, and the structure exhibits a bistable stress/strain curve under static tension. The function of the main link is to break early, at which point the waiting link becomes active and provides a redundant load path. The goal of the current study was to design, manufacture, and test a similar concept for impact loading and achieve greatly improved impact resistance per unit weight. In the current project, the main link was designed to be a brittle composite material (in this case, woven carbon/epoxy) exposed to impact, while the waiting link was chosen to be made with a highly nonlinear and strong composite material (in this case, polyethylene/epoxy), on the opposite surface. Hence, the structure, if proven successful, can be considered an enhanced hybrid concept. An explicit finite element (FE) commercial code, LS-DYNA, was used to design and analyze the baseline as well as two proposed designs. The simulations' methodology was validated with results published in the literature, which reported tests from linear fiber-reinforced composites. The plots were obtained via the ASCII files generated from the FE code, processed using matlab®, and compared to experimental impact tests. An instrumented drop-weight testing machine performed impact tests, and a high-speed camera validated the specimens' displacement under impact. It is shown that the FE model provided qualitative behavior very consistent with the experiments but requires further improvements. Experimentally, it is shown that one of the two enhanced hybrid models leads to up to a 30% increase of returned energy/weight when compared to its baseline and, therefore, is worthy of further investigations.

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