Research on the lightweight structural optimization design of the front collector of the polymetallic nodule miner

The polymetallic nodule miner (PNM) is prone to sink on deep-sea soft sediments due to its large weight, resulting in decreased mobility performance and mining efficiency. As a heavy-duty mechanism of the PNM, the weight reduction of the front collector (FC) can improve this issue. In this study, the lightweight optimization design of the FC was presented. The hydrodynamic forces on the FC were calculated by computational fluid dynamics (CFD) simulation and fully mapped as nodal loads into the finite element method (FEM) model to obtain the structural performance of the FC in the deep sea. Aluminum alloy and titanium alloy were applied in the FC, and then the structures of the FCs with different materials were optimized using the response surface method (RSM) surrogate model. After the lightweight design, the structure-optimized FC with steel, FC with aluminum alloy, and FC with titanium alloy were lightened by 4.15%, 19.22%, and 14.67%, respectively, while their structural performances were improved. A comparison of the optimization effects revealed that the application of aluminum alloys and further structural optimization comprises the optimal solution. The research conducted in this study provides a useful reference for the structural design of the FC.