Fatigue Behaviour and Electromechanical Properties of Additively
Manufactured Continuous Wire Polymer Composites for Structural Health
The fatigue behaviour of continuous wire polymer composite (CWPC)
fabricated by fused filament fabrication was investigated. Four
compositions were examined: polylactic acid (PLA), PLA with copper wire
(Cu), thermoplastic polyurethane (TPU), and TPU with Cu wire. Residual
properties were measured after different sets of number of cycles (10
2, 10 4, 10 5).
Residual strengths were 89.736% and 70.464% of the ultimate tensile
strength of the original material after 10 5 cycles
for PLA CWPC and TPU CWPC, respectively. A one-way analysis of variance
(ANOVA) statistical tests showed insignificant changes in the residual
strengths of PLA-based materials after an increasing number of cycles
and significant changes for the TPU-based materials. CWPC
electromechanical properties under fatigue test demonstrated reverse
piezoresistivity behavior. A strain-controlled fatigue life analytical
model was compared to the experimental results showing good agreement.
This study demonstrates the applicability of FFF technique to print
sensors with continuous integrated wire with tunable properties.