PSI - Issue 52

Muhammad Raihan Firdaus et al. / Procedia Structural Integrity 52 (2024) 309–322 M.R. Firdaus et al. / Structural Integrity Procedia 00 (2023) 000–000

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Fig. 6. Concurrent multi-scale modelling of float structure.

and / or reduced-order physics. Modelling complex structures require a very detailed process with huge numbers of elements and thus, resulting in high computational costs, in terms of computational time and resources. For a rather simpler structure, numerical computation can be computed using a macro-scale model. However, if within this model, there exists such regions where the deformation is very small, then a new e ff ective computation way is needed, where the scale is reduced to a smaller sample. The hybrid way in computing a structure consisting of a macro-scale and micro-scale mode is called as the multi scale modelling. Mainly multi-scale modelling is aiming in increasing the computational e ffi ciency, while maintaining the accuracy of the simulation. There are two common multi-scale modelling techniques, which are the concurrent multi-scale modelling and multi-stage multi-scale modelling. Concurrent multi-scale modelling is a method in ap proaching such multi-scale cases by computing the macro-scale and micro-scale exist within one global simultane ously. For instance, by implementing the shell-to-solid coupling in computing an aircraft pontoon, as the skin part is modelled using shell elements, while the bulkheads and spars are being approached as solid elements. Moreover, in concurrent multi-scale modelling, the quantities needed in the coarse scale model are computed on-the-fly from the fine scale models as the computation proceeds, while still providing information. A back-and-forth transfer of infor mation is concurrent and essential for the simulation of fracture and failure phenomena. On the contrary, the latter, which is also called as Sub-modelling is a technique that is used to study the more detailed part, on the local basis of a model, with a refined mesh based on interpolation of the solution from an initial global model.

3. Results and Discussion

3.1. Static Simulation

In the static simulation, the structure receives a distributed force that spread towards the entirety of the under-skin surface of the float structure. Figure 7 visually represents this condition by portraying purple arrows that emulate the dynamic force’s orientation during hydrodynamic impact simulation. Nevertheless, instead of exhibiting fluctuations in force magnitude as seen in dynamic simulation, the load employed in this static simulation remains resolutely constant. Within this analytical framework, the stress analysis centers its focus upon two components, namely the bulkheads and spars, as the regions of primary interest. The stress results obtained from the static simulations con-