## 1 Introduction  
Many complex products are manufactured through complex joining techniques, which often exhibit functional characteristics within the assembled structure. In the field of mechanical engineering, joining by forming is a conventional method [1; 2] that is frequently employed in conjunction with other techniques such as welding or brazing [3]. Press-fit connections are particularly prevalent in shaft-hub connections [4; 5; 6; 7; 8]. With the help of hydroforming [9] or shrinkage connections [10] with warmer hubs and colder connections, a frictional connection is adjusted between the two components. In typical applications, more often, several hubs are adjusted on a single shaft. This is exemplified in gear boxes and crank or rotor shafts [1; 4; 11]. Typically, the safety calculation for the transmittable torque of shaft-hub connections is conducted in accordance with the specifications outlined in DIN 7190 [12]. Furthermore, it is well-documented that materials exhibit disparate behaviors when subjected to varying strain rates: some display increased strength [13], some become brittle [14], and some even generate acoustic emissions during the loading process [15]. Complex assemblies may also result in the generation of complex and superimposed loads. For instance, vibrations emanating from one component can have a significant effect on the bearing [16; 17; 18]. This may lead to failure [17] in contact zones, but it may also overcome a disadvantage of press-fit connections: their non-destructive disassembly (in terms of not cutting both joining partners) [19]. In addition to low-frequency vibration-wave-assisted disassembly [19], it is also common practice to loosen up blocked mechanical parts caused by fretting [20; 21; 22] with an impact hit close to the connection. Similar effects are also described in so-called Impact Drive Mechanisms (IDMs), which deal with the frictional force and stick-slip in mechanical systems during the interactions of the surfaces and the near regions of two materials [23; 24], mostly in piezoelectric materials. Furthermore, somehow, similar effects were investigated in the classical tribological research area. In several papers, other groups investigated the influence of tangential vibration at low [25], high [26; 27], and very high frequencies [28]. At all frequency levels, specific values were found where the friction between both tribological partners was intensively reduced due to this transverse vibration. In [26; 27], computational models were developed that were able to reproduce the effects numerically. In [29], it was also found that even very low frequencies may influence failures under cycling load in what the authors called a creep-slip phenomenon. In a review work by [PERSON] et al. [30], three different locking mechanisms (to avoid such reduction in the frictional forces) were introduced: mechanical locking, friction-based locking, and singularity locking. The prevention of failure in the relative bolt connections is the focus of the work of [31]. The detailed experimental and numerical work comprises giving recommendations on the design features of threaded connections with collet nuts to prevent unintentional self-unscrewing [31]. In a more recent work, the same group proposed the concept of shell dampers with a shock absorber. They used the same mechanism backwards while filler material in the damper transformed longitudinal displacements of a piston into radial deformations of the shell so that no vibrational load may reduce friction in the connection, and to prevent unintentional self-unscrewing [32]. However, understanding the influence of single impact loads without permanent vibration on the transmittable torque of shaft-hub connections is so far not investigated. The mechanism described above may help to understand the result. In any case, it is essential to investigate this phenomenon for predicting and mitigating potential failures in mechanical systems.