- Thesis title：Analysis of crack trajectories using layout optimisation techniques
Layout optimization(LO)：This technique is used to analyze the crack trajectory instead of the finite element method or boundary element method
(Personal feeling: finally, write down and compare the three methods, and then say why Lo is used)
In this case, we are using Layout Optimisation tools for a totally new purpose. Layout Optimisation is concerned with finding the most efficient arrangement of tension and compression truss bars to carry a defined load to defined supports. (https://www.emerald.com/insight/content/doi/10.1108/02644400310503017/full/html) . But, the positions of the tension and compression bars also match the directions of the principal stresses in a solid with the same loads and the same supports. And in theory, cracks should form perpendicular to the direction of the maximum tension stresses. So, if we can identify that direction quickly and efficiently from a Layout Optimisation (LO) analysis(*) we can then position a “hole” in the design space, which represents the initial direction of the crack. Then we can re-run the analysis with this “hole” and see how the direction of the maximum tension changes. This way, by running the analysis several times, we can see if the LO approach accurately predicts the direction of the crack as it grows. If it does, then we may have a very useful new crack prediction method
- Purpose of the paper： The purpose of this work is to assess whether a new approach is suitable for determining the directions in which cracks will propagate in structural members. This is vitally important in a range of structural problems as structures approach their Ultimate Limit State. Cracks may develop in steel beams or connections, or in concrete walls, or beams, Being able to predict tier propagation with accuracy and efficiency (in terms of the computational effort) is something that could help structural designers.
Secondary：Layopt（URL software）：https://www.layopt.com/truss/ About this software, I recorded the screen when the tutor gave it to me to use, and I will send you the video
This paper describes how the “Geometry optimisation” works in LayOpt, moving bars away from the node points to find better solutions. https://eprints.whiterose.ac.uk/91607/11/SMOGeometryOptimization_Part2.pdf
Be sure to use one of these two! best to use！！！
- “Layout optimisation of large scale pin-jointed frames”
- This paper describes how the “Geometry optimisation” works in LayOpt, moving bars away from the node points to find better solutions. https://eprints.whiterose.ac.uk/91607/11/SMOGeometryOptimization_Part2.pdf
- I would like you, eventually, to look at a standard crack propagation problem, called a SEN beam. We will see if our method produces the expected shape of crack. You can get some idea of this by reading from p.116 in Prof Harm Askes’s PhD thesis here: https://repository.tudelft.nl/islandora/object/uuid:1f6cd5e6-08ad-4f0f-ba40-ea51ee0f4c16/datastream/OBJ/download
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