scholarly journals Investigating Fracture Properties of The Additively Manufactured PLA Using Sub-Size Specimens

2021 ◽  
Author(s):  
Sarinova Simandjuntak ◽  
Chulin Jiang ◽  
Tobias Kathke ◽  
David Sanders ◽  
Jiye Chen ◽  
...  
Keyword(s):  
Impact Test ◽  
Standard Procedure ◽  
Impact Testing ◽  
Energy Approach ◽  
Fused Deposition Modelling ◽  
Specimen Thickness ◽  
Fracture Properties ◽  
Air Gaps ◽  
Fused Deposition ◽  
The Impact

Abstract In the absence of an acceptable test standard for determining fracture properties of a single edge notched sub-size non-metallic (plastic) specimen, the test method’s viability of the ASTM-5045’s energy approach and the Roberts and Newton solution for Charpy V-Notch (CVN) impact testing was investigated. The strain energy release rate (SERR) and fracture toughness were determined by subjecting the sub-size specimens of additively manufactured Polylactic Acid (PLA) to a three-point flexural and a CVN impact testing. A Fused Deposition Modelling (FDM) technique was adapted to manufacture thin specimens by sequentially layering a 100mm thick raster in (-45/45)° and (0/90)° orientation. The toughness values of the flexural specimens increase with the number of layers (specimen thickness) and are clearly influenced by the layer orientation. Thicker CVN impact test specimens, however, resulted in relatively lower toughness values. This was due to a reduction of constraints for plane strain conditions that the existing impact test standard/procedure considered. When compared with the impact testing method, the flexural testing using the energy approach demonstrates a better capability to capture the effect of an increase in the energy absorbed for the air gaps to plastically deform and for the delamination to take place in the sub-size specimens. The X-Ray Tomographic images of the flexural test specimens confirmed the presence of air gaps where the onset of the cracking and delamination were observed, whilst the micrographic images revealed mode I intra-laminar fracture for all test specimens.

Effect of Hydrogen Content on Impact Property of A357 Alloy

2011 ◽  
Vol 704-705 ◽  
pp. 1201-1204 ◽  
Author(s):  
Yang Li ◽  
Zheng Bing Xu ◽  
Jian Min Zeng
Keyword(s):  
Crack Propagation ◽  
Hydrogen Content ◽  
Impact Test ◽  
Testing Machine ◽  
Initial Crack ◽  
Impact Testing ◽  
Total Absorption ◽  
A357 Alloy ◽  
Absorption Energy ◽  
The Impact

The impact specimens with different hydrogen contents were solution treated at 540±3°C for 12h; water quenched at 60-100°C; and aged at 165±1°C for 6h. The impact test was carried out at Roell450 pendulum impact testing machine. The impact test results show that the impact energy has strong relation with the hydrogen content. The total absorption energy increases with the increasing of hydrogen content. The crack propagation energy Avp and present larger proportion than the initial crack energy Avi in the total absorption energy Av. The number of the pinholes increases and the pinholes turn from smaller irregular ones into sub-circular shape ones. The specimen with irregular sub-circular pinholes has larger KI, and has more crack propagation resistance.

Localised Pre-Heating to Improve Inter-Layer Delamination Strength in Fused Deposition Modelling

2019 ◽  
Author(s):  
Andrew Aitchison ◽  
Qing Wang
Keyword(s):  
Tensile Strength ◽  
Thermal Energy ◽  
Fused Deposition Modeling ◽  
Acrylonitrile Butadiene Styrene ◽  
Additive Manufacture ◽  
Fused Deposition Modelling ◽  
Print Quality ◽  
Air Gaps ◽  
Fused Deposition ◽  
Air Temperatures

Abstract Additive manufacture, specifically Fused Deposition Modeling (FDM), is an advancing manufacture method opening up new possibilities in design previously impossible to machine, in a relatively affordable way. However, its use in functional products is limited due to anisotropic strength and reduced strength from injection molded components. This paper aims to increase the tensile strength of Acrylonitrile Butadiene Styrene (ABS) in the weakest direction (Z axis), where poor interlayer fusion and air gaps between extruded trails reduce strength. Extra thermal energy was applied to the top surface layer during the printing process (through hot air) to encourage more polymer chain diffusion across the boundary, and spreading out to fill air gaps. Multiple tensile test samples were printed at a variety of heat levels. The ultimate tensile strength σuts was plotted against these temperatures and a weak positive correlation was found. However, only air temperatures above 81°C increased strength past the control to a maximum of 1.4MPa. Heat application has proven to increase tensile strength, but needs to be applied with a more precise method, to the boundary interface, to allow greater thermal energy transfer without sacrificing print quality.

scholarly journals High Velocity Impact Test on Glass Fibre Reinforced Polymer (GFRP) Using a Single Stage Gas Gun (SSGG) - An Experimental Based Approach

2014 ◽  
Vol 564 ◽  
pp. 376-381 ◽  
Author(s):  
N. Razali ◽  
Mohamed Thariq Hameed Sultan ◽  
S.N.A. Safri ◽  
Shahnor Basri ◽  
Noorfaizal Yidris ◽  
...  
Keyword(s):  
Composite Material ◽  
Impact Test ◽  
Impact Force ◽  
Specimen Thickness ◽  
Gas Gun ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
The Impact

The aim of this work is to study the effect of thickness and type of bullet in impact test on structures made from a composite material. The composite material used in this study was Glass Fibre Reinforced Polymer (GFRP). This material was fabricated to produce laminated plate specimens with dimension of 100 mm × 100 mm and 6, 8, 10, and 12 mm thickness. The impact test was performed using a Single Stage Gas Gun (SSGG) with blunt, hemispherical, and conical types of bullets. The gas gun pressure was set to 5, 10, 15 and 20 bar. In the tests, gas gun pressure, bullet type and specimen thickness were varied to ascertain the influence of these parameters on the materials response. The relation between impact force with gas pressure, type of bullets and specimens thickness are presented and discussed. The best thickness for GFRP was identified according to the impact results. From the impact tests conducted, it was found that at the same amount of pressure, the higher the thickness, the bigger the impact force because as the specimen thickness increases, the amount of impact force absorbed by the specimen is higher.

scholarly journals Environmental and Management Factors Affecting Carrot Cracking

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 852B-852
Author(s):  
T.K. Hartz* ◽  
P.R. Johnstone ◽  
J.J. Nunez
Keyword(s):  
Air Temperature ◽  
Impact Test ◽  
Irrigation Management ◽  
Nutrient Status ◽  
N Fertilization ◽  
Impact Testing ◽  
Dominant Factor ◽  
Factors Affecting ◽  
The Impact ◽  
Cracking Sensitivity

Cracking of carrot (Daucus carota L.) roots during harvest and handling is a serious problem for the commercial industry, particularly for `cut and peeled' products. Thirty commercial fields of cv. `Sugar Snax' in California were surveyed over the period 2000-03. Soil texture was determined, and soil and crop nutrient status, air temperature and soil moisture were monitored. In 10 fields the effect of excessive N fertilization was investigated; 90-180 kg·ha-1 N was sidedressed in addition to the growers' N regime. At one site a comparison of 10 cultivars was conducted to determine the root cracking sensitivity of commercial cultivars suitable for the cut and peeled market. In all fields roots were hand harvested, with undamaged roots 18-24 mm in diameter selected for study. Roots were cooled to 5 °C and subjected to an impact test to rate cracking sensitivity. Fields varied widely in root cracking sensitivity, with 4% to76% of roots cracked in the impact test. Cracking sensitivity was positively correlated with the % silt and clay in soil, and with air temperature in the final month of growth. Irrigation management had no consistent effect on cracking sensitivity. N application in excess of the growers' N regime did not increase carrot yield, but increased root cracking sensitivity by an average of 30%. Root cracking varied among cultivars from 10% to 49%. However, when the periderm was peeled from roots before impact testing, incidence of cracking declined to 2% or less in all cultivars. Periderm strength or flexibility is apparently the dominant factor in carrot cracking sensitivity, and environmental and management variables that affect cracking sensitivity must do so by affecting the periderm structure.

scholarly journals Investigation on the Application of Taylor Impact Test to High-G Loading

2021 ◽  
Vol 8 ◽  
Author(s):  
Li Juncheng ◽  
Chen Gang ◽  
Lu Yonggang ◽  
Huang Fenglei
Keyword(s):  
Pulse Duration ◽  
Impact Loading ◽  
Impact Test ◽  
Impact Load ◽  
Low Cost ◽  
Large Mass ◽  
Impact Testing ◽  
Taylor Impact ◽  
Taylor Impact Test ◽  
The Impact

Taylor impact test is characterized by high impact energy, low cost, and good repeatability, giving it the technical foundation and development potential for application in high-g loading. In this paper, the feasibility of performing high-g load impact testing to a missile-borne recorder by conducting Taylor impact test was studied by combining simulation analyses with experimental verification. Acccording to the actual dimensions of the missile-borne recorder, an experimental piece was designed based on the Taylor impact principle. The impact loading characteristics of the missile-borne recorder were then simulated and analyzed at different impact velocities. In addition, the peak acceleration function and the pulse duration function of the load were fitted to guide the experimental design. A Taylor-Hopkinson impact experiment was also conducted to measure the impact load that was actually experienced by the missile-borne recorder and the results were compared with the results of strain measurements on the Hopkinson incident bar. The results showed that the peak value of impact load, the pulse duration and the waveform of the actual experimental results were in good agreement with the results predicted by the simulations. Additionally, the strain data measured on the incident bar could be used to verify or replace the acceleration testing of the specimen to simplify the experimental process required. Based on the impact velocity, high-g loading impact was achieved with peak values in the 7,000–30,000 g range and durations of 1.3–1 ms, and the waveform generated was a sawtooth wave. The research results provide a new approach for high amplitude and long pulse duration impact loading to large-mass components, and broaden the application field of Taylor impact test.

scholarly journals Impact, Hardness and Fracture Morphology of Aluminium Alloy (Al-Si) filled Cobalt Oxide Nanoparticles at Various Stir Casting Temperatures

2021 ◽  
Vol 5 (1) ◽  
pp. 11-20
Author(s):  
Mardy Suhandani ◽  
Poppy Puspitasari ◽  
Jeefferie Abd Razak
Keyword(s):  
Impact Toughness ◽  
Melting Temperature ◽  
Impact Test ◽  
Casting Process ◽  
Fracture Morphology ◽  
Stir Casting ◽  
Impact Testing ◽  
Test Results ◽  
The Impact ◽  
Coo Nanoparticles

The automotive and aviation fields require engineering materials that can save and optimise fuel consumption. Unique characteristics of lightweight, higher strength to weight ratio, good corrosion resistance, and good castability are indispensable for castable metal such as Silicon Aluminium (Al-Si). The mechanical properties of Al-Si could be further improved through the addition of Cobalt Oxide (CoO) nanoparticles during the casting process. The importance and purpose of this study were to determine the impact toughness, hardness and fracture morphology of Al-Si metal alloy filled with 0.015 wt.% CoO nanofiller at the various melting temperature of 750 °C, 800 °C and 850 °C. The stir casting method was utilised considering the most appropriate method for mixing nanoparticles powder into the Al-Si matrix. Three test specimens were prepared for each temperature variation. Impact testing using the Charpy method (ASTM E23-56 T) and hardness testing using Rockwell Superficial HR15T and fracture morphology obtained from impact testing fractures were performed accordingly. The impact test results showed that the Al-Si added with 0.015% CoO at 800 °C of melting temperature possessed the highest impact toughness value of 25.111 x 10-3 Joule mm-2 than the other variations. The hardness test results showed that Al-Si added 0.015% CoO with a melting temperature of 850 °C had the highest hardness value of 79.52 HR15T. The fracture morphology of the impact test in all specimens shows uniform brittle fracture characteristics. It is found that the melting temperature during the stir-casting process of Al-Si has played a significant role in influencing the resulted properties of Al-Si filled CoO nanoparticles metal matrix composites. The selection of an accurate melting temperature for the stir casting process will affect the resulted properties of produced metal composites.

scholarly journals DYNAMIC IMPACT WEAR AND IMPACT RESISTANCE OF W-B-C COATINGS

2020 ◽  
Vol 27 ◽  
pp. 37-41
Author(s):  
Josef Daniel ◽  
Jan Grossman ◽  
Vilma Buršíková ◽  
Lukáš Zábranský ◽  
Pavel Souček ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Protective Coatings ◽  
Impact Resistance ◽  
Impact Testing ◽  
The Novel ◽  
Test Results ◽  
Dynamic Impact ◽  
Impact Deformation ◽  
The Impact

Coated components used in industry are often exposed to repetitive dynamic impact load. The dynamic impact test is a suitable method for the study of thin protective coatings under such conditions. Aim of this paper is to describe the method of dynamic impact testing and the novel concepts of evaluation of the impact test results, such as the impact resistance and the impact deformation rate. All of the presented results were obtained by testing two W-B-C coatings with different C/W ratio. Different impact test results are discussed with respect to the coatings microstructure, the chemical and phase composition, and the mechanical properties. It is shown that coating adhesion to the HSS substrate played a crucial role in the coatings’ impact lifetime.

scholarly journals Parameters Affecting the Mechanical Properties of Three-Dimensional (3D) Printed Carbon Fiber-Reinforced Polylactide Composites

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2456
Author(s):  
Demei Lee ◽  
Guan-Yu Wu
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
3D Printing ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Layer By Layer ◽  
Fused Deposition ◽  
Bed Temperature ◽  
3D Printed ◽  
The Impact

Three-dimensional (3D) printing is a manufacturing technology which creates three-dimensional objects layer-by-layer or drop-by-drop with minimal material waste. Despite the fact that 3D printing is a versatile and adaptable process and has advantages in establishing complex and net-shaped structures over conventional manufacturing methods, the challenge remains in identifying the optimal parameters for the 3D printing process. This study investigated the influence of processing parameters on the mechanical properties of Fused Deposition Modelling (FDM)-printed carbon fiber-filled polylactide (CFR-PLA) composites by employing an orthogonal array model. After printing, the tensile and impact strengths of the printed composites were measured, and the effects of different parameters on these strengths were examined. The experimental results indicate that 3D-printed CFR-PLA showed a rougher surface morphology than virgin PLA. For the variables selected in this analysis, bed temperature was identified as the most influential parameter on the tensile strength of CFR-PLA-printed parts, while bed temperature and print orientation were the key parameters affecting the impact strengths of printed composites. The 45° orientation printed parts also showed superior mechanical strengths than the 90° printed parts.

Impact of 3D-printing structure on the tribological properties of polymers

2020 ◽  
Vol 72 (6) ◽  
pp. 811-818 ◽  
Author(s):  
Muammel M. Hanon ◽  
Róbert Marczis ◽  
László Zsidai
Keyword(s):  
3D Printing ◽  
Tribological Properties ◽  
Future Research ◽  
Fused Deposition Modelling ◽  
Wear Depth ◽  
Printing Process ◽  
Content Type ◽  
Fused Deposition ◽  
Polylactide Acid ◽  
The Impact

Purpose The purpose of this paper is to examine the impact of three-dimensional (3D)-printing process settings (particularly print orientation) on the tribological properties of different polymers. Design/methodology/approach In this study, fused deposition modelling 3D-printing technology was used for fabricating the specimens. To evaluate the influence of print orientation, the test pieces were manufactured horizontally (X) and vertically (Z). The tribological properties of various printed polymers, which are polylactide acid, high tensile/high temperature-polylactide acid and polyethylene terephthalate-glycol have been studied. The tribological tests have been carried out under reciprocating sliding and dry condition. Findings The results show that the presence of various orientations during the 3D-printing process makes a difference in the coefficient of friction and the wear depth values. Findings suggest that printing structure in the horizontal orientation (X) assists in reducing friction and wear. Originality/value To date, there has been very limited research on the tribology of objects produced by 3D printing. This work was made as an attempt to pave the way for future research on the science of tribology of 3D-printed polymers.

Development of New Composite Materials for Rapid Tooling Using Fused Deposition Modelling

2014 ◽  
Vol 808 ◽  
pp. 103-108 ◽  
Author(s):  
Harish Kumar Garg ◽  
Rupinder Singh
Keyword(s):  
Rapid Prototyping ◽  
Fused Deposition Modeling ◽  
Research Work ◽  
Rapid Tooling ◽  
Industrial Applications ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
The Impact ◽  
Feedstock Material

The impact of Rapid Prototyping (RP) on the future engineering and manufacturing will undoubtedly be widespread .It has variety of applications which include the manufacture of prototypes know as rapid prototyping, tool cores and cavities know as rapid tooling and in the manufacture of patterns for a range of casting processes known as rapid casting. In the proposed research work, fused deposition modeling (FDM) technique of RP will be used for development of a tool for direct application using Rapid tooling. The research work includes development of new hybrid feedstock filament of Fe – Nylon6 composite material for the FDM machine which will be suitable for the machine in its existing setup. The feedstock filament will have the desired mechanical thermal and rheological properties as desired for Rapid Tooling applications. The proposed feedstock material will be ferromagnetic in nature and can find wide application in industrial applications.

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