Piezomagnetic Behaviour of Wire Arc Additively Manufactured Steel Single-lap Shear Bolted Connections

In this paper, the piezomagnetic response of single-lap shear failure of wire arc additively manufactured (WAAM) steel bolted connections was investigated. It aims to explore the use of piezomagnetic measurement as a nondestructive method to detect the failure process of WAAM steel connections under shear loads. The mechanical properties of the materials were obtained by monotonic tensile tests on coupons with different directions of loading relative to the deposition direction. Then, 36 connecting specimens with two printing layer orientations and varying dimensions were tested to failure. The stress-induced magnetic fields around the specimens were monitored online by magnetic probes throughout the loading process. It is found that the anisotropy of WAAM steel can be observed from the piezomagnetic response. The failure modes of lap connections include net section tension, end-splitting, shear-out and tilt-bearing. The results show that the magnetic response exhibits similar behavior to the mechanical response. It is possible to predict the failure mode of the specimens using the magnetic field-displacement curve. The study demonstrates that the piezomagnetic field can be an important indicator of impending shear failure of WAAM steel elements.