Abstract (EN):
The repair of composites and sandwich structures is studied experimentally and
numerically. Repair is fundamental to avoid premature replacement of damaged components.
Efficient predictive numerical tools of the mechanical behaviour of repaired structures are
necessary to increase the confidence of designers. In this context, cohesive damage models
have acquired special relevancy owing to their capacity to simulate damage onset and growth.
A mixed-mode cohesive damage model based on interface finite elements and accounting for
ductile behaviour of adhesives is presented. The cohesive parameters of the constitutive
softening laws are determined using an inverse method applied to fracture characterization
tests under pure modes I and II. A new data reduction scheme based on crack equivalent
concept is applied in the fracture characterization tests. The cohesive laws are used to predict
the mechanical behaviour of scarf repairs of composites and sandwiches. Good agreement
was found between experimental and numerical results, for strength versus scarf angle,
showing that the proposed model can be successfully applied to bonded repairs.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
20