明星八卦

The project proposes a novel way to numerically model delamination or debonding in layered structures using:

• beam-type finite elements for the layers, which can be geometrically linear or nonlinear, and
• novel mixed-mode, rate-dependent cohesive-zone models (CZMs) for the interface.

In this way, the project shall provide new, more accurate, more intuitive and computationally much cheaper techniques than those currently available, that will be implemented in open-source user-friendly software and experimentally validated for mode-I, mode-II and mixed-mode tests on aluminium-epoxy adhesive joints.

Engineers will be able to numerically simulate tests with different dimensions and material properties to characterise the fracture energy and its rate dependence for existing or new adhesives or other interfaces, with applications including but not limited to metal joints, composite delamination, reinforced elastomers or dissection of soft tissues in biomedical engineering.

The research builds on complementary and internationally highly recognised expertise of the researcher and his  (on geometrically nonlinear beam models) and the  (on CZMs and nonlinear finite-element analysis). 

The researcher will have the opportunity to

1. develop world-leading knowledge and expertise in a research topic of significant importance for industrial and reallife applications,
2. transfer it to a country where such expertise is limited and
3. boost his scientific career and international profile through high-quality publications  and via his leadership in the development of the software. This will also provide numerous networking opportunities with other research groups and industries worldwide for allparties involved in the action.

Aims and objectives:

Specific objectives are:

1. to develop a new finite element where a mixed-mode, co-rotational rate-independent interface element is sandwiched between layers modelled as geometrically nonlinear beams;
2. to introduce rate dependence in the mixed-mode co-rotational CZM;
3. to extend the CZM to capture large-strain rate-dependent effects in the cohesive zone using a hyperviscoelastic model for the undamaged interface;
4. to provide a robust set of benchmark experimental data for debonding and peeling tests of adhesive joints, for varying mixed-mode ratios and test speeds but the same adherend material and adhesive;
5. to validate the models against the debonding and peeling test results with agreement within 10% and against fully 3D nonlinear FE models with agreement within 5%;
6. to implement the model within an open-source and user-friendly software dedicated to the analysis of delamination, debonding and peel tests, with parametric input.