Near-field beamforming analysis for acoustic emission source localization

► A near-field acoustic emission (AE) beamforming method is introduced. ► Pencil lead break tests at various regions of a thin steel plate are conducted. ► The beamforming method is used to localize source of the rotor–stator rubbing. ► This method is an effective tool to estimate the location of an AE source. This paper attempts to introduce a near-field acoustic emission (AE) beamforming method to estimate the AE source locations by using a small array of sensors closely placed in a local region. The propagation characteristics of AE signals are investigated based on guided wave theory to discuss the feasibility of using beamforming techniques in AE signal processing. To validate the effectiveness of the AE beamforming method, a series of pencil lead break tests at various regions of a thin steel plate are conducted. The potential of this method for engineering applications are explored through rotor–stator rubbing tests. The experimental results demonstrate that the proposed method can effectively determine the region where rubbing occurs. It is expected that the work of this paper may provide a helpful analysis tool for near-field AE source localization.