{'fraction_non_alphanumeric': 0.015988372093023256, 'fraction_numerical': 0.0, 'mean_word_length': 5.066079295154185, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A study on the effects of self-piercing riveting methods on the joint

: As the regulations on exhaust gas strengthened, the research and development of devices to reduce air pollutants emitted from vehicles have continued. Lightweight design that influences the fuel efficiency of vehicles has become an essential consideration due to the use of exhaust gas reduction systems. The early lightweight design started as a concept of replacing steel materials with aluminum or ultrahigh tensile steel. However, bi-metals with high strength and light weight are now being designed and developed instead of single materials. For bonding of bi-metal sheets, the self-piercing riveting method is being generally applied to double sheets with an upper high-tensile steel plate and a lower aluminum alloy plate. However, there is insufficient research to solve the problem of the costs of power consumption and consumable parts and low bonding strength of the joint due to the potential corrosion of parts that occur in the rivet joint. This study proposed a new self-piercing riveting method after punching (SPRP) method that can prevent the reduction of bonding force of the rivet joint and minimize the stress and forming load required for bonding. Furthermore, the possibility of rivet bonding with corrosion resistance and bonding force was proved through experiment and analysis.