scholarly journals Effects of the Face/Core Layer Ratio on the Mechanical Properties of 3D Printed Wood/Polylactic Acid (PLA) Green Biocomposite Panels with a Gyroid Core

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2929
Author(s):  
Nadir Ayrilmis ◽  
Rajini Nagarajan ◽  
Manja Kitek Kuzman
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Surface Layer ◽  
Layer Thickness ◽  
Polylactic Acid ◽  
Brinell Hardness ◽  
Skin Thickness ◽  
Bending Modulus ◽  
Screw Withdrawal ◽  
Surface Layer Thickness

Gyroid structured green biocomposites with different thickness face layers (0.5, 1, 2 and 2.5 mm) were additively manufactured from wood/ polylactic acid (PLA) filaments using a 3D printer. The mechanical properties of the composite panels, bending properties, compressive strength (parallel to the surface), Brinell hardness, and face screw withdrawal resistance, were determined. The surface layer thickness significantly affects the mechanical properties of the composite materials. As the surface layer thickness was increased from 0.5 to 2.5 mm, all the mechanical properties significantly improved. In particular, the Brinell hardness and face screw withdrawal resistance of the specimens improved sharply when the skin thickness was higher than 2 mm. The bending strength, bending modulus, compressive strength (parallel to the surface), Brinell hardness, and face screw withdrawal resistance of the specimens with a skin of 0.5 mm were found to be 8.10, 847.5, 3.52, 2.12 and 445 N, respectively, while they were found to be 65.8, 11.82, 2492.2, 14.62, 26 and 1475 N for the specimens with a 2.5 mm skin. Based on the findings from the present study, gyroid structured composites with a thickness of 2 mm or higher are recommended due to their better mechanical properties as compared to the composites with skins that are thinner.

Mechanical Behaviour of Polylactic Acid Parts Fabricated via Material Extrusion Process: A Taguchi-Grey Relational Analysis Approach

2020 ◽  
Vol 46 ◽  
pp. 32-44
Author(s):  
Peter Kayode Farayibi ◽  
Babatunde Olamide Omiyale
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Layer Thickness ◽  
Polylactic Acid ◽  
Process Parameters ◽  
Grey Relational Analysis ◽  
Extrusion Temperature ◽  
Relational Analysis ◽  
Grey Relational

The acceptance and application of functional parts produced via additive manufacturing technologies is faced with challenges of poor surface finish, dimensional accuracy and mechanical properties among other which is mostly dependent on process parameters employed. In this study, the effect of infill density, layer thickness and extrusion temperature on mechanical properties of polylactic acid (PLA) part manufactured using fused deposition modelling process was investigated to obtain optimum process parameters to achieve the best properties. Solid cuboid bars were produced from which tensile, impact and hardness test specimens were obtained. A statistical approach based on Taguchi design of experiment was employed with process parameters varied and grey relational analysis coupled with principal component analysis was employed to obtain the unified optimum parameter. The single optimisation results showed that 50% infill density, 220°C extrusion temperature and 0.4 mm layer thickness resulted in best tensile strength; 30% density, 210°C temperature and 0.2 mm layer thickness is required to achieve the best impact strength, while 50% density, 215°C temperature and 0.3 mm thickness is required for highest hardness. The multi-response optimisation indicated that for the best of all the three properties to be achieved at once in a PLA built part, 50% infill density, 220°C extrusion temperature and 0.3 mm is required which yielded tensile strength of 30.02±2.15 MPa, impact strength 4.20±0.12 J and hardness of 76.80±0.38 BHN.

scholarly journals The effect of the titanium surface layer thickness on the characteristics of a layered composite material

2019 ◽  
Vol 1281 ◽  
pp. 012057 ◽  
Author(s):  
E O Nasakina ◽  
M A Sudarchikova ◽  
K Yu Demin ◽  
M A Gol’dberg ◽  
M I Baskakova ◽  
...  
Keyword(s):  
Composite Material ◽  
Surface Layer ◽  
Layer Thickness ◽  
Titanium Surface ◽  
Layered Composite ◽  
Layered Composite Material ◽  
Surface Layer Thickness

Analytic GPR data processing for surface layer thickness assessment

2019 ◽  
Author(s):  
Vânia Marecos ◽  
José Pedro Figueiredo ◽  
Simona Fontul ◽  
Mercedes Solla
Keyword(s):  
Surface Layer ◽  
Data Processing ◽  
Layer Thickness ◽  
Surface Layer Thickness

scholarly journals An Analytical Model of the Response of the Meridional Overturning Circulation to Changes in Wind and Buoyancy Forcing

2012 ◽  
Vol 42 (8) ◽  
pp. 1270-1287 ◽  
Author(s):  
Callum J. Shakespeare ◽  
Andrew McC. Hogg
Keyword(s):  
Surface Layer ◽  
Layer Thickness ◽  
Analytical Model ◽  
Wind Stress ◽  
North Atlantic ◽  
Meridional Overturning Circulation ◽  
The North ◽  
The North Atlantic ◽  
Surface Buoyancy ◽  
Surface Layer Thickness

Abstract An analytical model of the full-depth ocean stratification and meridional overturning circulation for an idealized Atlantic basin with a circumpolar channel is presented. The model explicitly describes the ocean response to both Southern Ocean winds and the global pattern and strength of prescribed surface buoyancy fluxes. The construction of three layers, defined by the two isopycnals of overturning extrema, allows the description of circulation and stratification in both the upper and abyssal ocean. The system is fully solved in the adiabatic limit to yield scales for the surface layer thickness, buoyancies of each layer, and overturning magnitudes. The analytical model also allows scaling of the Antarctic Circumpolar Current (ACC) transport. The veracity of the three-layer framework and derived scales is confirmed by applying the analytical model to an idealized geometry, eddy-permitting ocean general circulation model. Consistent with previous results, the abyssal overturning is found to scale inversely with wind stress, whereas the North Atlantic overturning and surface-layer thickness scale linearly with wind stress. In terms of the prescribed surface buoyancy fluxes, increased negative fluxes (buoyancy removal) in the North Atlantic increase the North Atlantic overturning and surface-layer thickness, whereas increased positive fluxes in the middle and low latitudes lead to a decrease in both parameters. Increased negative surface buoyancy fluxes to the south of Drake Passage increase the abyssal overturning and reduce the abyssal buoyancy. The ACC transport scales to first order with the sum of the Ekman transport and the abyssal overturning and thus increases with both wind stress and southern surface buoyancy flux magnitude.

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