The Computational Model
This stage of the project involves the development of a computational model which will incorporate information obtained from the laboratory tests as well as results from previous research. The model will employ the widely-used finite element method and will be created, validated and analysed using the Abaqus software.
The following list outlines key points in terms of the modelling work:
The aim of the model is to help study the response of the strengthened beam as affected by the behaviour of the adhesive joint at different temperatures.
|
This requires a finer mesh in the region of the beam where the CFRP plate ends (for study of debonding effects) as well as along the length of the epoxy bond and the plate itself. Coarser mesh can be used in other parts of the beam where the behaviour is not of significant interest to this project (e.g. local buckling of the steel beam).
The diagram above highlights the material properties that will need to be input into the computational model. It is known that steel and CFRP are unaffected by warm temperatures however the adhesive is. The material behaviour at different temperatures needs to be accurately modelled within the model. It is important to ensure the robustness of the model and as a first pass check this will be done by comparing the ambient temperature analysis against hand calculations. At later stages similar checks will need to be carried out at elevated temperatures. A further issue that will need to be researched is the application of the actions on the FE beam model - loads and particularly thermal actions. Careful consideration will need to be take to ensure that the elevated temperature situations are modelled in a manner consistent with what is likely to be encountered on site. |
Finite Element Analysis
In this final stage all of the information that has been researched or obtained through laboratory tests and combined into the FE model will be used to answer questions about the behaviour of the composite section. Examples of actions and loading scenarios that will be used in the analysis are listed below:
|
The results then will be critically examined and conclusions will be drawn regarding the behaviour of the composite section at warm temperatures. |