FDM technology and the effect of printing parameters on the tensile strength of ABS parts

Abstract

The effect of printing speed on the tensile strength of acrylonitrile butadiene styrene (ABS) samples fabricated using the fused deposition modelling (FDM) process is addressed in this research. The mechanical performance of FDM-ABS products was evaluated using four different printing speeds (10, 30, 50, and 70 mm/s). A numerical model was developed to simulate the experimental campaign by coupling two computational codes, Abaqus and Digimat. In addition, this article attempts to investigate the impacts of printing parameters on ASTM D638 ABS specimens. A 3D thermomechanical model was implemented to simulate the printing process and evaluate the printed part quality by analysing residual stress, temperature gradient and warpage. Several parts printed in Digimat were analysed and compared numerically. The parametric study allowed us to quantify the effect of 3D printing parameters such as printing speed, printing direction, and the chosen discretisation (layer by layer or filament) on residual stresses, deflection, warpage, and resulting mechanical behaviour.

Keywords: ABS material; Abaqus/Digimat coupling; Fused deposition modelling; Printing speed.

Fig. 1

Geometry and dimensions of the tensile specimens [24]

Fig. 2

Characterisation of the mechanical properties of FDM-ABS specimens: (a) Printed tensile specimen and (b) tensile testing configuration [24]

Fig. 3

Representative true stress. True strain curves for the manufactured tensile specimens with different printing speeds

Fig. 4

Kinetics of a coupled Abaqus/Digimat computation

Fig. 5

Coupling procedure between Abaqus and Digimat

Fig. 6

Mapped manufacturing data visualised on the structural model, filament orientation (eigenvector)

Fig. 7

Specimen mesh C3D8R

Fig. 8

Stress-strain curve for a printing speed of 10 mm/s

Fig. 9

Work sequences in Digimat-AM

Fig. 10

Superposition of the mesh between Abaqus and Digimat

Fig. 11

Stress-strain curves for a printing speed of 10 mm/s

Fig. 12

Stress-strain curve determined numerically for 4 printing speeds

Fig. 13

Residual stresses at the end of the manufacturing process

Fig. 14

Deflection at the end of the manufacturing

Fig. 15

Technique for scanning many layers of an ASTM-D638 part (type IV)

Fig. 16

A few frames for 3D printing of polymer composites using layer deposit FDM process: variation of the temperature

Fig. 17

Profile of temperature and Von Mises stress utilising the layer deposit technique at various points of the ABS thickness

Fig. 18

Layer-by-layer vs filament discretisation

Fig. 19

Comparison of the temperature profile for two printing techniques

Fig. 20

Variation of the stress concentration and the temperature for two processes

Fig. 21

Printing direction

Fig. 22

Curves determined numerically for printing direction 45/−45, 0/90, 60/−60

Fig. 23

Warping of ABS specimen

Fig. 24

Printing cost for an ABS specimen