{'fraction_non_alphanumeric': 0.02385685884691849, 'fraction_numerical': 0.0019880715705765406, 'mean_word_length': 5.414012738853503, '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}}
Impact-reduction effect by applying ultrasonic vibrations to a cylindrical hot-melt adhesive

Impact-reduction structures and materials are used for many applications such as the crushable zones of vehicles and buffers for precision equipment. However, they do not absorb sufficient energy from the impact in all cases. Furthermore, the impact-reduction characteristics cannot be changed instantaneously. As such, in this study, we aim to develop an impact-reduction system by applying ultrasonic vibrations that can change the rigidity of the material instantaneously in the event of an impact. We developed an experimental device to confirm the impact-reduction effect of applying ultrasonic vibrations to a hot-melt adhesive (HMA). The vibration characteristics of the ultrasonic transducer and the impact-reduction characteristics were measured. The ultrasonic transducer was driven almost as designed. Furthermore, the impact force was reduced by up to 20% by the application of ultrasonic vibrations.