Numerical Analysis of Specimen Size Influence on Dynamic Behaviour of Al 2014 Alloy Using SHPB Technique

The Split Hopkinson Pressure Bar (SHPB) technique is most commonly used to study the dynamic behaviour of materials when subjected to high-speed impact. The influence of the specimen size and shape plays a predominant role in estimating the flow stress behaviour of the Al 2014 alloy that is widely used in aerospace applications. In the present study, numerical analysis is carried out on three specimen shapes—Circular, Square, Demi-bull-nosed; and the corresponding L/D ratios of 0.5, 1 and 1.5 are estimated for the various specimen shapes. Flow stress–strain curves are compared with each other and found that the demi-bull-nosed specimens have shown moderate stresses, which could be a substitute for the circular specimens during their non-availability. These specimens were further analysed for their dynamic behaviour for the three strain rates of 2857.1/s, 5714.3/s and 8571.43/s. The variation of L/D or L/S ratios revealed that the lower ratio of 0.5 resulted in higher flow stresses with large deformation behaviour. The simulation results were further validated with the available experimental results of compression SHPB, which are in tandem with each other.