Measurement of Yield Strength and Flow Properties in Spot Welds and Their HAZs at Various Strain Rates
Haggag, F.M. and Bell, G.E.C., "Measurement of Yield Strength and Flow Properties in Spot Welds and Their HAZs at Various Strain Rates," International Trends in Welding Sciences and Technology, ASM International, 1993, pp. 637–642.
This paper demonstrates ABI® measurement on resistance spot welds — geometrically challenging targets due to their small area (typically 5–8 mm diameter nuggets). The inclusion of strain-rate sensitivity data establishes that ABI® results are comparable to conventional tests across strain rates relevant to automotive crashworthiness and impact loading.
Resistance spot welds are the primary joining method in automotive body structures, with a typical vehicle containing 3,000–5,000 spot welds. The mechanical properties of these welds — particularly in the HAZ — directly affect vehicle crashworthiness. However, the small size of spot weld nuggets makes conventional mechanical testing extremely difficult.
By demonstrating that ABI® can characterize both the nugget and HAZ properties of spot welds, and that the results are consistent across strain rates relevant to crash loading, this paper opened a potential application for ABI® in automotive quality control and crash safety assessment.