Impact-reduction effect by applying ultrasonic vibrations to a cylindrical hot-melt adhesive

Abstract

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.

Ultrasound source using a rectangular vibrating plate combined with rigid walls

“…The interval between the sound pressure antinodes corresponds roughly to the values calculated using Eqs. (11) and (12).…”

“…Ultrasound is used in various fields. [1][2][3][4][5][6][7][8][9][10][11][12][13] In particular, ultrasound is used for deodorization, atomization, and aerosol aggregation. [14][15][16][17][18][19][20][21][22] These applications require intense ultrasound waves.…”

Convergence of intense aerial acoustic waves radiated by a rectangular transverse vibrating plate

“…Ultrasound is used in a wide variety of fields. [1][2][3][4][5][6][7][8][9][10][11] In particular, ultrasound in air is used for purposes such as the flocculation of microparticles and the atomization of liquids. [12][13][14][15][16][17][18][19] However, these applications require powerful ultrasound, which can be produced by methods such as forming standing-wave acoustic fields and focusing sound waves emitted from a sound source.…”

Development of an impact-reduction device by applying ultrasonic vibrations to a high-strength steel plate using a downsized transducer

“…[3][4][5][6][7] In addition, many studies have investigated the use of ultrasonic vibrations in plastic deformation. [8][9][10][11][12][13][14][15][16][17][18][19][20] We have previously reported on the deformation and impact-reduction characteristics when ultrasonic vibrations are applied to aluminum-alloy plates, 21) aluminumalloy pipes, 21) cylindrical hot-melt adhesives, 22,23) and highstrength steel plates. 24) The high-strength steel plate (tensile strength: 590 to 710 N=mm 2 ) was bent at an angle of 52°, and the maximum impact force was 314 N when ultrasonic vibrations were not applied.…”

“…24) While the length of the ultrasonic transducer used in previous studies was 435 mm, an extra-large transducer must be used for the application of the impact-reduction system to a crushable zone in vehicles. [21][22][23][24] However, an oversized transducer increases the overall weight and size of the vehicle and reduces fuel economy. Moreover, it is difficult to drive many transducers; therefore, it is important to downsize the impactreduction device.…”