## 4 Conclusions  
During initial impact testing, severe shear, hybrid, and flexural damage occurred for the beams. Only Beam A2 failed during the initial test, but significant damage occurred for the other beams as shown by the large crack widths, permanent displacement, and reduction in fundamental frequency. The beams with the least amount of shear reinforcement mainly showed shear damage, and the beams with the most shear reinforcement showed flexural damage.  
Figure 16: (**a**) Damage to Beam A1 after quasi-static testing; (**b**) damage to Beam B1; (**c**) damage to Beam C1; (**d**) damage to Beam D1; (**e**) damage to Beam E; and (**f**) damage to Beam F.  
Beam B2 showed a hybrid response throughout the sequential impact tests with considerable flexural and shear damage that led to a varying response. Beam D2 showed mainly flexural damage, and the response was similar across the five impact tests. This indicates that beams with large shear reinforcement amounts present a similar response during sequential impact tests with an accumulation of mainly flexural damage. Sequential impact testing also showed that local failure becomes critical for beams containing high reinforcement amounts that prevent global failure.  
The full measured acceleration signals showed that the damage to the beams was coupled to the time for the second prominent peak during the test to occur. Beam A2 showed no second prominent peak as the striker's energy was absorbed by the opening of the wide flexural shear crack, causing no spring-back for the beam. The beams presenting severe damage with residual capacity showed their second prominent peak earlier than the beams which sustained less degree of damage.  
Preliminary CWT analyses on the signals during the first impact test showed that several frequency ranges contained high energy concentrations for beams with significant shear damage. Beams which instead showed mainly flexural damage showed energy concentration in one frequency range. Fictitious energy in low-frequency ranges occurred due to measurement error.  
When comparing Beams E and B1 after residual quasi-static capacity testing, it was shown that the initial flexural cracks of Beam B1 had a favourable effect, as the response became ductile after initial impact testing. Beam D1 showed a brittle failure mode while testing the residual quasi-static capacity, although it contained the most shear reinforcement. This was explained by a possibly low static shear capacity of steep diagonal cracks, resulting in severe consequences of significant shear plug damage on the residual static capacity.  
Both Beams A1 and A2 showed significant global flexural shear damage and shear plug damage after the initial impact test. However, the less steep global shear damage was shown to be critical for the residual static and impact capacity.  
V.P.: conceptualisation, methodology, formal analysis, writing--original draft preparation, and writing--review and editing. A.A. and M.H.: review, validation, and editing. All authors have read and agreed to the published version of the manuscript.  
This work is financially supported by the Swedish Transport Administration, the Swedish Fortifications Agency, the Swedish Civil Contingencies Agency (MSB) and Tyrens AB. Funding for the experimental testing was provided by the Fortification corps' research fund (Fortification-skarens forskningsfond).  
Not applicable.  
All datasets presented in this study are included in the article.  
The authors would like to acknowledge [PERSON] and [PERSON] at the KTH Royal Institute of Technology laboratory for their assistance with the experiments. The assistance by [PERSON] and [PERSON] is also acknowledged.  
The authors declare no conflict of interest.