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The Influence of Background Ultrasonic Field on the Strength of Adhesive Zones under Dynamic Impact Loads
- Source :
- Materials, Volume 14, Issue 12, Materials, Vol 14, Iss 3188, p 3188 (2021)
- Publication Year :
- 2021
- Publisher :
- MDPI, 2021.
-
Abstract
- The influence of background ultrasonic field on the ultimate dynamic strength of adhesive joints is studied using fracture mechanics analysis. Winkler foundation-type models are applied to describe the cohesion zone, and the incubation time fracture criterion is used. The challenging task is to study whether relatively weak ultrasound is able to decrease the threshold values of the external impact load depending on a joint model, such as an “elastic membrane” or “beam” approximation, and various boundary conditions at the ends. The specific task was to investigate the case of short pulse loading through application of time-dependent fracture criterion instead of the conventional principle of critical stress. Three different load cases, namely, step constant force, dynamic pulse, and their combination with ultrasonic vibrations, were also studied. The analytical solution to the problem demonstrates that background vibrations at certain frequencies can significantly decrease threshold values of fracture impact load. Specific calculations indicate that even a weak background sonic field is enough to cause a significant reduction in the threshold amplitude of a dynamic short pulse load. Additionally, non-monotonic dependency of threshold amplitude on pulse duration for weak background field was observed, which demonstrates the existence of optimal regimes of impact energy input. Moreover, this phenomenon does not depend on the way in which the beam edges mount, whether they are clamped or hinged, and it could be applied for micro-electro-mechanical switch design processes as an additional tool to control operational regimes.
- Subjects :
- Technology
Materials science
02 engineering and technology
Article
0203 mechanical engineering
General Materials Science
fracture dynamics
Joint (geology)
background ultrasonic field
Microscopy
QC120-168.85
dynamic impact
QH201-278.5
Pulse duration
Fracture mechanics
Mechanics
Engineering (General). Civil engineering (General)
021001 nanoscience & nanotechnology
TK1-9971
Pulse (physics)
Vibration
020303 mechanical engineering & transports
Descriptive and experimental mechanics
Fracture (geology)
adhesive joint strength
Ultrasonic sensor
Electrical engineering. Electronics. Nuclear engineering
TA1-2040
incubation time criterion
0210 nano-technology
Beam (structure)
Subjects
Details
- Language :
- English
- ISSN :
- 19961944
- Volume :
- 14
- Issue :
- 12
- Database :
- OpenAIRE
- Journal :
- Materials
- Accession number :
- edsair.doi.dedup.....a8dc09c00eb28052c94bf810ab57aa71