Validation of the low-velocity impact damage prediction through analytical scaling

Abstract

The analytical scaling method for low-velocity impact permits an efficient application of impact analysis through high-fidelity numerical simulation. Structural impact scenarios can be analyzed on a small damage-prone section, called reference coupon. An analytical spring-mass model transfers the damage result from the reference coupon to the structural level. In this article, we investigate the validity of that scaling method. A large set of experimental impact scenarios forms the basis to identify the capabilities of scaled impact analysis. In a further critical assessment, we identify the corresponding limitations. These mainly concern the geometry of the impact configurations – the damage can shift its mode when the impact occurs close to supported edges or stiffening elements. Besides, the experimental results indicate an increased uncertainty from the reference impact to the total all scaled impact scenarios. Furthermore, the impact analysis through quasistatic scaling entails a systematic bias. Smaller damage than expected occurs in several cases. The excitation of higher-order vibration modes explains this observed bias. An initial value problem of the impact configuration allows conducting a modal energy correction. This energy correction explains the systematically too small size of scaled impact damage.