Research on influence of cyclic degradation process on changes of structural adhesive bonds mechanical properties
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Kuupäev
2019
Kättesaadav alates
Autorid
Kolář, V.
Tichý, M.
Müller, M.
Valášek, P.
Rudawska, A.
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
The paper deals with an influence of a cyclic degradation process on changes of a shear
tensile strength of single lap-shear adhesive bonds and their elongation according to ČSN EN
ISO 9142. Five one-component structural adhesives used in a construction of car body works
were used within the research. The degradation of adhesive bonds is a significant factor which
influences a quality and a service life of adhesive bonds exposed to environment. A main
requirement in production companies is not only reaching satisfactory initial mechanical
properties but namely ensuring a reliability and a safety of adhesive bonds during their usage.
These reasons show a great importance of adhesive bonds tests either directly in the operating
environment or by a simulation of operating conditions in laboratories. The degradation process
of adhesive bonds worsens mechanical properties of not only the bond itself but also of the bonded
material. This process is progressing and it is usually permanent and irreversible. It is a change
of mechanical and physical properties which can endanger a safety and a reliability of parts,
prospectively of the whole equipment. It can leads up to a complete failure of its function in the
extreme case. A temperature, a moisture, a direct contact with water and chemicals or an
atmospheric corrosion belong among the most serious degradation agents. It is important to take
into regard time of the processes influence at the same time which can act either independently
or concurrently when their effects grow stronger.
From that reason the adhesive bonds were exposed to the cyclic degradation process according
to the standard ČSN EN ISO 9142. Subsequently, the adhesive bonds mechanical properties were
tested on universal testing machine and by means of SEM analysis (TESCAN MIRA 3).
Results of mechanical tests proved a fall of the shear tensile strength of single lap-shear adhesive
bonds after 42 cycles of the degradation process of 12.8 to 21.7%. The bond strength fall was
gradual and it showed a linear trend at some adhesives. Other adhesives showed a significant fall
after the exposition to the degradation process after which the strength fall stabilized.
Kirjeldus
Article
Märksõnad
shear tensile strength, elongation, temperature, moisture, SEM, automotive, ageing process, articles