Abstract (EN):
In the most recent years, structural applications of bonded joints have
increased remarkably owing to their several advantages relative to other
joining methods. As a consequence, the development of improved models
to provide design effi ciency and, at the same time, increase the confi dence
of designers acquires special relevancy. Recent developments considering
cohesive and continuum mixed-mode damage models have demonstrated
that these methods are able to deal with several details inherent to
mechanical behaviour of bonded joints. Both methods allow simulation
of damage initiation and propagation by combining classical strength of
materials approaches with fracture mechanics concepts.
In this work, several different mixed-mode cohesive laws adapted to
different types of adhesives mechanical behaviour are presented and discussed.
Effectively, while mechanical behaviour of brittle or moderately ductile
adhesives is well simulated by means of the simple bilinear cohesive
law, adhesives with pronounced ductile behaviour require more sophisticated
cohesive laws. The aspects regarding determination of some cohesive
parameters are also given special attention in the present paper. A continuum
mixed-mode damage model is also presented using the bilinear softening
cohesive law. This model is advantageous since properties degradation takes
place inside solid elements used to simulate the adhesive, which allows the
evaluation of specifi c issues like the infl uence of asymmetric propagation
on joint mechanical behaviour in a more realistic manner. Important conclusions
about advantages and drawbacks of both methodologies are drawn.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
24
License type: