TWI

A qualitative and discrete quantitative approach was adopted to develop a generalised electronic NDE (e-NDE) algorithm for identifying erratic friction stir welding (FSW) indications contained in the tool force feedback signals as low and high frequency events. The spindle frequency of the welding tool was selected as a threshold between low and high frequency ranges. Process conditions based on a pseudo heat input concept were used to examine a qualitative relationship between low frequency events and tool travel/spindle speeds under ideal conditions. An heuristic model based on a pseudo-shear-stress concept was redefined to include discrete radial forces and tangential forces, and then employed to characterise high frequency events of the force feedbacks in terms of the process dynamics. Generic acceptable and unacceptable weld indications in the force feedback were used to formulate a qualitative approach to the e-NDE algorithm.

9th International Symposium, 15-17 May 2012, Session 2B: Inspection, Paper 01