scholarly journals Influence of sample thickness, curvature and notches on the Charpy impact strength - An approach to standardise the impact strength of curved test specimens and biological structures

2021 ◽  
Vol 93 ◽  
pp. 106864
Author(s):  
Nina Graupner ◽  
Niels Kühn ◽  
Jörg Müssig
Keyword(s):  
Impact Strength ◽  
Charpy Impact ◽  
Sample Thickness ◽  
Biological Structures ◽  
Charpy Impact Strength ◽  
The Impact

Bioinspired engineering polymers by voxel-based 3D-printing

2016 ◽  
Vol 17 (3-4) ◽  
Author(s):  
Theresa Swetly ◽  
Jürgen Stampfl ◽  
Gero Kempf ◽  
Rainer-Michael Hucke ◽  
Marcus Willing ◽  
...  
Keyword(s):  
Impact Strength ◽  
Charpy Impact ◽  
Edge Length ◽  
Product Development Process ◽  
Geometrical Quality ◽  
Short Period ◽  
Engineering Polymers ◽  
Charpy Impact Strength ◽  
The Impact ◽  
Soft Elastomer

AbstractAdditive manufacturing (AM) has become an important tool in the product development process as it offers the possibility to produce parts of good geometrical quality within a short period of time, allowing geometrical validations and the visualisation of ideas. Yet the application of AM is often limited due to the poor mechanical properties of AM parts. In the automotive sector for example, there is a high demand for tough AM parts which have an impact strength comparable to industrially moulded thermoplasts. This paper explores the possibility to increase the impact strength of AM parts by combining a stiff, hard and brittle component (VeroWhite Plus in this instance) with a soft, elastomer-like component (TangoBlack Plus) and arranging these on a micro-scale level in form of alternating, chess-pattern voxels. While one material was responsible for maintaining a sufficient stiffness and strength of the resulting composite structure, the other material acted as an obstacle for crack propagation. Varying the edge length of the voxels, it was possible to investigate the influence of the microscopic voxel geometry on the part’s macroscopic impact strength. It was shown that the Charpy impact strength could be raised by a factor of eight (from 10.9 kJ/m

Impact fracture toughness and morphology of polypropylene/Mg(OH)2 composites

2013 ◽  
Vol 33 (8) ◽  
pp. 721-725 ◽  
Author(s):  
Ji-Zhao Liang ◽  
Feng-Jiao Li
Keyword(s):  
Impact Strength ◽  
Charpy Impact ◽  
Weight Fraction ◽  
Impact Fracture ◽  
Increase With Increase ◽  
Impact Fracture Behavior ◽  
Twin Screw ◽  
Izod Impact ◽  
Charpy Impact Strength ◽  
The Impact

Abstract Magnesium hydroxide [Mg(OH)2] with high flame retardant efficiency filled polypropylene (PP) composites were prepared using a twin-screw extruder. The impact fracture behavior of the composites was measured at room temperature. It was found that the toughening effect of the filler content on the PP resin was significant. The V-notched Izod impact strength of the PP/Mg(OH)2 composites showed a nonlinear increase with increase in filler weight fraction (ϕf), as ϕf was <15%, and then it decreased slightly; When ϕf was <15%, the V-notched Charpy impact strength of the PP/Mg(OH)2 composite also increased nonlinearly, then it decreased slightly. The impact fracture surface was observed by means of a scanning electronic microscope, to understand the toughening mechanisms for the composite systems.

Energy Absorption Property of CFRP under Impact Loadings

2014 ◽  
Vol 566 ◽  
pp. 219-224 ◽  
Author(s):  
Ding Ding Chen ◽  
Ryo Matsumoto ◽  
Kazuo Arakawa ◽  
Sangjae Yoon
Keyword(s):  
Impact Strength ◽  
Energy Absorption ◽  
Charpy Impact ◽  
Polymeric Composite ◽  
Absorption Property ◽  
Fiber Break ◽  
Fracture Modes ◽  
Notch Length ◽  
Charpy Impact Strength ◽  
The Impact

Because of high stiffness, high strength and low density, etc., polymeric composite materials are widely used in high technology area, such as aeronautic and aerospace engineering where impact is one of the most common loadings. In this paper, impact energy absorption properties of a carbon fiber reinforced plastic (CFRP) plate, which was made through vacuum assisted resin transfer molding (VARTM) process, were tested though Charpy impact tests with single-edge notched specimens. In the experiments, the effects of impact directions and notch length on the energy absorption property were considered. The results show different impact directions lead to different Charpy impact strength and different fracture modes. When the angle between the fiber and the impact direction is large, fiber break mode dominates the break, exhibiting higher Charpy impact strength. When the impact direction-fiber angle is small, delamination is the main fracture mode, showing lower Charpy impact strength. Depending on different fracture modes, the enhancement of the resin due to a post curing process has totally opposite effects on the Charpy impact strength. For the delamination mode, the enhancement of resin increases the Charpy impact strength of the CFRP specimen. However, for the fiber break mode, it decreases the impact strength. This phenomenon can be attributed to the effect of voids. The impact strength calculated from the typical formula is also affected by the initial notch length significantly, because the fracture surface in this experiment is no longer a plane.

scholarly journals Improving Mechanical Properties of PLA/Starch Blends Using Masterbatch Containing Vegetable Oil Based Active Ingredients

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2981
Author(s):  
Bianka Nagy ◽  
Norbert Miskolczi ◽  
Zoltán Eller
Keyword(s):  
Impact Strength ◽  
Vegetable Oil ◽  
Rapeseed Oil ◽  
Flexural Modulus ◽  
Charpy Impact ◽  
Sem Images ◽  
Elongation At Break ◽  
Starch Concentration ◽  
Starch Blends ◽  
Charpy Impact Strength

The aim of this research was to increase the compatibility between PLA and starch with vegetable oil-based additives. Based on tensile results, it can be stated, that Charpy impact strength could be improved for 70/30 and 60/40 blends in both unconditioned and conditioned cases, regardless of vegetable oil, while no advantageous change in impact strength was obtained with PLA-g-MA. Considering sample with the highest starch concentration (50%), the flexural modulus was improved by using sunflower oil-based additive, Charpy impact strength and elongation at break was increased using rapeseed oil-based additive in both conditioned and unconditioned cases. SEM images confirmed the improvement of compatibility between components.

The Effect of Chitosan Addition in Acrylic Resin Matrix towards the Residual Monomers and Impact Strength

2021 ◽  
pp. 2280-2285
Author(s):  
Titik Ismiyati ◽  
Ananto Ali Alhasyimi
Keyword(s):  
Acrylic Acid ◽  
Impact Strength ◽  
Charpy Impact ◽  
Acrylic Resin ◽  
Test Sample ◽  
Acid Group ◽  
Resin Matrix ◽  
Residual Monomer ◽  
Group 2 ◽  
The Impact

Background: A residual monomer might have impact on the quality of acrylic resin since its caused allergic reactions and inflammation. Chitosan is a biocompatible material and potential to reduce residual monomers and ameliorate the impact strength of acrylic resin Objective of the study: To examine the effect of an acrylic resin matrix mixed with chitosan together with 1% and 2% acrylic acid as denture base and orthodontic material on residual monomers and impact strength. Methodology: There were 30 samples for the test analysis. The impact strength test sample formed with a plate size of 55 × 10 × 10mm, whereas the residual monomer test sample was prepared into powder. The test samples were divided into 3 groups, of 10 samples. Group 1 acrylic resin only, group 2 acrylic resin matrix mixed with chitosan and 1% acrylic acid, group 3 is the same as group 2 but with a concentration of 2% acrylic acid. Gas chromatography was used for measuring the residual monomers. The impact strength was tested by the Charpy impact. The data was evaluated using the ANOVA and correlation test. Results: There were significant differences (p < 0.05) in acrylic resin without addition with the matrix of acrylic resin with chitosan and acrylic acid 1% and 2% to the number of monomers and impact strength. Conclusion: The mixture of acrylic resin with chitosan and acrylic acid 1% and 2% can reduce the amount of residual monomer and increase the impact strength.

scholarly journals The Effect of Crystallinity on the Toughness of Cast Polyamide 6 Rods with Different Diameters

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 293
Author(s):  
Miklós Odrobina ◽  
Tamás Deák ◽  
László Székely ◽  
Tamás Mankovits ◽  
Róbert Zsolt Keresztes ◽  
...  
Keyword(s):  
Impact Strength ◽  
Impact Test ◽  
Charpy Impact ◽  
Polyamide 6 ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Tensile Impact ◽  
Different Diameters ◽  
The Impact ◽  
The Degree Of Crystallinity

The present paper concentrates on the toughness and the degree of crystallinity of the magnesium-catalyzed polyamide 6 rods cast in different diametres, which are commonly used for gear manufacturing. Its toughness cannot be regarded as a constant feature due to the casting technology. The mechanical properties of the semi-finished products are sensitive to the manufactured dimension, e.g., cast diameter, which are investigated by the Charpy impact test and tensile impact test. It is generally accepted that the impact strength and tensile-impact strength correlate with the degree of crystallinity beside many other material’s feature. Crystallinity is evaluated by Differential Scanning Calorimetry. The aim of this study is to determine the relationship between toughness and crystallinity of the magnesium-catalyzed cast PA6 rods with different diameters. For the research cast rods between 40 and 300 mm diameter were selected in seven-dimensional steps. Based on the results, it was found that the toughness depends strongly on the diameter size. Furthermore, it is proved that the crystallinity explains 62.3% of the variation of the Charpy’s impact strengths, while the tensile impact method was not suitable to detect the difference between the test samples.

scholarly journals An Experimental Study on the Effect of Nanomaterials and Fibers on the Mechanical Properties of Polymer Composites

Buildings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Chanachai Thongchom ◽  
Nima Refahati ◽  
Pouyan Roodgar Saffari ◽  
Peyman Roudgar Saffari ◽  
Meysam Nouri Niyaraki ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Modulus Of Elasticity ◽  
Graphene Nanosheets ◽  
Charpy Impact ◽  
Tensile Tests ◽  
Basalt Fibers ◽  
Low Weight ◽  
Internal Mixer ◽  
The Impact

This study aims to explore the tensile and impact properties (tensile strength, modulus of elasticity, and impact strength) of polypropylene (PP)-based nanocomposites reinforced with graphene nanosheets, nanoclay, and basalt fibers. The response surface methodology (RSM) with Box–Behnken design (BBD) was adopted as the experimental design. An internal mixer was used to prepare compounds consisting of 0, 0.75 and 1.5 wt% graphene nanosheets, 0, 10 and 20 wt% basalt fibers, and 0, 3 and 6 wt% nanoclay. The samples were prepared by a hot press machine for mechanical testing. The tensile tests were run to determine the tensile strength, and modulus of elasticity, and the Charpy impact tests were performed to assess the impact strength. It was found that the addition of basalt increased the tensile strength, modulus of elasticity, and impact strength by 32%, 64% and 18%, respectively. Also, the incorporation of the low-weight graphene nanosheets increased the tensile and impact strength by 15% and 20%, respectively, Adding graphene nanosheets generally improved the modulus of elasticity by 66%. Similarly, the addition of nanoclay improved the tensile strength by 17% and increased the modulus of elasticity by 59%, but further addition of it decreased the impact strength by 19%. The values obtained by this experiment for the mechanical property were roughly close to the data yielded from desirability optimization.

scholarly journals Impact Strength of Austenitic and Ferritic-Austenitic Cr-Ni Stainless Cast Steel in -40 and +20°C Temperature

2014 ◽  
Vol 59 (3) ◽  
pp. 1103-1106
Author(s):  
B. Kalandyk ◽  
R. Zapała ◽  
Ł. Boroń ◽  
M. Solecka
Keyword(s):  
Impact Strength ◽  
Volume Fraction ◽  
Cast Steel ◽  
Testing Machine ◽  
Charpy Impact ◽  
Impact Testing ◽  
Two Phase ◽  
Steel Grades ◽  
Charpy Impact Testing ◽  
The Impact

Abstract Studies described in this paper relate to common grades of cast corrosion resistant Cr-Ni steel with different matrix. The test materials were subjected to heat treatment, which consisted in the solution annealing at 1060°C followed by cooling in water. The conducted investigations, besides the microstructural characteristics of selected cast steel grades, included the evaluation of hardness, toughness (at a temperature of -40 and +20oC) and type of fracture obtained after breaking the specimens on a Charpy impact testing machine. Based on the results of the measured volume fraction of ferrite, it has been found that the content of this phase in cast austenitic steel is 1.9%, while in the two-phase ferritic-austenitic grades it ranges from 50 to 58%. It has been demonstrated that within the scope of conducted studies, the cast steel of an austenitic structure is characterised by higher impact strength than the two-phase ferritic-austenitic (F-A) grade. The changing appearance of the fractures of the specimens reflected the impact strength values obtained in the tested materials. Fractures of the cast austenitic Cr-Ni steel obtained in these studies were of a ductile character, while fractures of the cast ferritic-austenitic grade were mostly of a mixed character with the predominance of brittle phase and well visible cleavage planes.

Sign in / Sign up

Export Citation Format

Share Document