## 1 Introduction  
Self-piercing riveting (SPR) is a method used for mechanically attaching similar or dissimilar materials [1]. The process works by creating an interlock between the top and the bottom sheets or panels using a rivet that fully penetrates the top but not the bottom panel. SPR has several advantages: (1) a simple process with no requirement of predrilled holes [2], (2) easy automation and a short cycle time with excellent reproducibility [3], (3) no dust, chips, and heat fumes as associated with a welding process [4], (4) eco-friendly and sustainable, since no waste material is produced [5], and (5) very little or no damage to pre-coated materials [3]. The process is especially useful in joining dissimilar materials such as carbon fiber reinforced plastic (CFRP) [6; 7; 8], copper [9], titanium [9], aluminum alloys [10; 11], and steel [11; 12], in which the use of conventional joining methods is challenging. In the modern auto-industry, the use of functional and lightweight materials such as aluminum alloy, high-strength steel, and carbon composites is increasing [13; 14]. Vibration-damping aluminum (Al) panels are now being widely used to form cowl and dash panels for increased passenger comfort and overall weight reduction of the vehicles. The use of such dissimilar materials requires efficient means of joining, since the conventional fusion joining methods are not applicable. Up to now, despite their drawbacks, non-fusion methods, including chemical bonders and conventional mechanical fasteners, have been used. The toxic chemicals comprising the bonders pose severe health and environmental risks, while the conventional mechanical joining methods require manual alignment of panels that is difficult to automate [15]. Therefore, the industry is shifting to fasteners that need no prefabricated holes, such as SPR [16; 17], clinching [18; 19], and flow drill screw (FDS) [20]. Nevertheless, limited studies are available, in the open academic literature, discussing novel methods for joining dissimilar materials [21]. The effects of the rivet and die types on SPR of aluminum alloy (AA6061) and mild steel (CR4) were investigated by [PERSON] et al. [22] under various processing configurations. An experimental and numerical investigation of the self-piercing rivet joint between aluminum alloy (A5052-H34) and mild steel (SPCC) was done by [PERSON] et al. [23]. The mechanical characteristics of self-piercing riveted joints in multiple layers composed of aluminum (AA6111 and NG5754) and steel alloys (HSLA350) were studied by [PERSON] et al. [24]. The performance of various self-piercing riveted joints (tension, shear, and peel joint) using aluminum sheets (A5754) was investigated by [PERSON] et al. at standard car crash test speeds [25]. The joint quality of self-piercing riveted CFRP/aluminum, steel/aluminum, and CFRP/steel/aluminum with three layers was investigated by our group [7; 8; 9]. The bonding quality of self-piercing riveted joints of vibration-damping steel and aluminum alloy was also recently studied by our group [26]. Nevertheless, to the best of the authors' knowledge, no comprehensive study has been performed for SPR between novel materials used in the automotive industry such as vibration-damping aluminum (Al), aluminum alloy, steel alloy, and carbon-reinforced plastic (CFRP). Here, we investigate the geometrical characteristics and mechanical performance of the SPR of vibration-damping Al with aluminum alloy (AL5052-H32), steel alloy (GA590 DP), and thermoset CFRP. The differences are studied of the geometrical and mechanical characteristics of the joints according to the specimen configuration and die type. Three types of dies are used to form the rivet joints, and the cross-section is examined to investigate the joint quality of different panel configurations. The joint qualities (or joining strengths) were determined using a series of tensile shear load tests, and the failure modes were examined to shed light on the critical forces acting on the joints that eventually lead to their failures.