What qualifies as "good PDA data" during a high strain dynamic load test?


The velocity records should be similar. Strain (force) records should have similar frequency content to velocity records, and should return to near zero (or reach a slightly negative value) when the impact has clearly ended (this is indicated by a flat line on the velocity record). If one strain record has some “high frequency content” that the others do not, then something may be wrong with the strain transducer corresponding to that record (a bolt may be loose causing it to behave as an accelerometer).