Active control of stress intensity in the cracked 3D‐printed specimens using shape memory alloy wires

Abstract

Intelligent composite structures are designed to retard crack initiation and growth in a controlled manner using shape memory alloys (SMAs). The crack closure under mixed‐mode I/II conditions in the 3D‐printed specimens reinforced with pre‐strained SMAs is investigated using numerical, analytical, and experimental procedures. The stress intensity factors (SIFs) of the semicircular bending (SCB) samples are theoretically estimated based on the micromechanical model where the wires are entirely perpendicular to the crack planes, and findings are verified with those data obtained using numerical and experimental methods. Stable crack growth, interlayer adhesion, and fracture toughness improvement are obtained in the modified test samples. In terms of strength and fracture toughness, SMA with 1% pre‐strain is introduced as an optimal value in both pure mode I and mixed‐mode I/II conditions.