Optimization Design Of Porous Heat Dissipation Structure Based On TPMS

Triply periodic minimal surfaces(TPMSs)have been widely used in many engineering fields,including tissue engineering,lightweight manufacturing,and biomedicine.Although TPMSs have many nice properties that make them very suitable for thermal property analysis,there has been little work that has applied TPMSs in this important field due to the high complexity of the representation and optimization methods of the porous structure.This paper presents an efficient representation and optimization of TPMS-based porous structures for heat dissipation.First,the porous shell structure is established by a function representation that is derived by the implicit function representations of TPMSs.It inherits the good properties of TPMSs,such as full connectivity,high smoothness,infinite ductility and controllability.At the same time,this porous structure also has excellent thermal and mechanical properties such as high surface-to-volume ratio,high strength and high stiffness.Then,according to the steady-state heat conduction equation,the heat dissipation problem can be formulated into a minimization problem dealing with the thermal compliance using the given volume and gradient constraints.Next,to solve the problem directly on function representation without the time-consuming re-meshing,an efficient optimization method with differentiable optimization process is exploited.And then,the heat dissipation optimization problem is solved numerically through the discrete model.In the process of numerical calculation,the double-scale grid method is used,the coarse and thin grids are used to solve the temperature field and the accurate geometric calculation respectively,and the global-local radial basis interpolation method is also used to represent the parameter function with the limited control points.Both of these strategies save a lot of computing time and memory consumption.Finally,by updating the design variables through the optimization algorithm,we obtain the optimized porous shell structures with smooth period and wall-thickness changes.Various experiments were conducted showing that the proposed porous structures have obvious advantages in terms of efficiency and effectiveness.Moreover,due to its characteristics of self-support,smoothness and full connectivity,the proposed structure is very suitable for additive manufacturing technology.