Search

CN-121744419-B - Porous structure design method and system with closed outer contour

CN121744419BCN 121744419 BCN121744419 BCN 121744419BCN-121744419-B

Abstract

The application relates to the technical field of porous structure design, in particular to a porous structure design method and a porous structure design system with a closed outer contour, wherein the method comprises the steps of constructing a prosthesis three-dimensional model; the method comprises the steps of taking the outer contour of a model as a reference, layering from outside to inside according to preset intervals to obtain a plurality of closed three-dimensional layering interfaces, arranging growing points on each three-dimensional layering interface, projecting the growing points to the surface of an equivalent sphere, expanding the surface of the equivalent sphere to a two-dimensional standard domain for layout optimization, reversely calculating three-dimensional coordinates of the growing points based on reverse mapping, connecting the growing points on adjacent layers to form polygonal cell units, and finally stacking to form a complete porous structure. The application solves the problems of uniform generation, topological continuity and manufacturing constraint integration of the porous structure on the complex curved surface through geometric mapping and parameterized optimization, and realizes the structural personalized design and manufacturing integration.

Inventors

  • WANG SEN
  • YANG CHAO
  • Yin Hubin

Assignees

  • 重庆云生生物科技有限公司

Dates

Publication Date
20260512
Application Date
20260227

Claims (10)

  1. 1. A method of designing a porous structure having a closed outer contour, comprising the steps of: constructing a three-dimensional model of the target prosthesis; Layering the three-dimensional model from outside to inside based on a preset interval by taking the outer contour of the three-dimensional model as a reference to obtain a plurality of closed three-dimensional layering interfaces, wherein the outer three-dimensional layering interfaces in the two adjacent three-dimensional layering interfaces are outer layer interfaces; Setting a plurality of growth points on each three-dimensional layering interface according to a preset rule; projecting each three-dimensional layered interface and each growth point to a preset equivalent sphere surface to obtain a projection point of each growth point on the equivalent sphere surface; Expanding and mapping the equivalent sphere surface to a standard two-dimensional parameter domain, and executing preset optimization adjustment operation on the layout of the projection points in the standard two-dimensional parameter domain to obtain the coordinates of each projection point on the standard two-dimensional parameter domain after optimization; Based on the coordinates of the projection points on the standard two-dimensional parameter domain and the mapping relation from the three-dimensional layering interface to the standard two-dimensional parameter domain, reversely calculating to obtain final coordinate data of each growth point in the three-dimensional space; polygonal cell formation: The growth points on the outer layer interfaces in the two adjacent three-dimensional layered interfaces are used as first nodes on the polygonal cell bodies between the two adjacent three-dimensional layered interfaces, and the growth points on the inner layer interfaces in the two adjacent three-dimensional layered interfaces are used as second nodes on the polygonal cell bodies; the first nodes and the second nodes are connected to form a polygonal cell body positioned between two adjacent three-dimensional layered interfaces, edges formed by connecting a plurality of first nodes or surfaces formed by enclosing a plurality of first nodes on the polygonal cell body are positioned on the same outer layer interface, and edges formed by connecting a plurality of second nodes or surfaces formed by enclosing a plurality of second nodes on the polygonal cell body are positioned on the same inner layer interface.
  2. 2. The method of designing a porous structure having a closed outer contour as claimed in claim 1, wherein: the step of connecting the first node and the second node when forming the polygonal cell body comprises: Searching a second node in a preset three-dimensional space distance range by taking final coordinate data of the first node as a reference; If a plurality of second nodes exist in the distance range, selecting the second node closest to the three-dimensional space of the first node for connection; if no second node exists in the distance range, the distance range is increased according to a preset step length, and searching is carried out again until connection is successful.
  3. 3. The method of designing a porous structure having a closed outer contour as claimed in claim 2, further comprising the steps of: identifying isolated growing points that are not connected to any polygonal cell bodies; Searching for an existing polygonal cell body in a preset connection radius by taking the isolated growth point as a center; If the polygon cell is searched, the isolated growing point is connected to the searched polygon cell, and if the polygon cell is not searched, the isolated growing point is deleted.
  4. 4. A method of designing a porous structure having a closed outer contour as defined in claim 3, further comprising the steps of: Calculating the proportion of the number of the isolated growth points to the number of all the growth points to obtain the proportion of the isolated growth points; If the isolated growth point occupation ratio is lower than a first preset threshold value, confirming to output a current porous structure model; If the isolated growth point occupation ratio is between the first preset threshold value and a second higher preset threshold value, generating a diagnosis report containing an isolated growth point distribution area and parameter adjustment suggestions; and if the isolated growth point occupation ratio is higher than the second preset threshold value, judging that the current design rule fails and suggesting a preset rule according to which the growth point is generated by backtracking adjustment.
  5. 5. The method of designing a porous structure having a closed outer contour as defined in claim 1, further comprising the steps of: acquiring curvature distribution of the three-dimensional layered interface; reducing the preset interval according to a first preset reduction for a region with curvature greater than a first preset curvature threshold; Increasing the preset interval according to a second preset increasing amount aiming at the area with curvature smaller than a second preset curvature threshold value; keeping the preset interval unchanged for a region with a curvature value between the second preset curvature threshold and the first preset curvature threshold; wherein the second preset curvature threshold is less than or equal to the first preset curvature threshold.
  6. 6. The method of designing a porous structure having a closed outer contour as claimed in claim 1, wherein: the optimization adjustment operation includes adjusting for a preset porosity threshold range and adjusting for a 3D printing minimum feature size determined based on a manufacturing process.
  7. 7. The method according to any one of claims 1 to 6, wherein the layering is performed by iso-surface extraction.
  8. 8. The method of designing a porous structure having a closed outer contour according to any one of claims 1 to 6, wherein said polygonal cell is a triangular prism or a hexahedron.
  9. 9. The method of designing a porous structure with a closed outer contour according to any of claims 1-6, wherein said two-dimensional parameter domain is an equivalent unit circle.
  10. 10. A cellular stmcture design system having a closed outer contour, the system comprising: the three-dimensional model construction module is configured for constructing a three-dimensional model of the target prosthesis; The layering processing module is configured to perform layering processing on the three-dimensional model from outside to inside based on a preset interval by taking the outer contour of the three-dimensional model as a reference to obtain a plurality of closed three-dimensional layering interfaces, wherein the three-dimensional layering interfaces at the outer sides of two adjacent three-dimensional layering interfaces are outer-layer interfaces; The growth point generation module is configured to set a plurality of growth points on each three-dimensional layered interface according to a preset rule; The first projection module is configured to project each three-dimensional layered interface and each growth point onto a preset equivalent sphere surface to obtain a projection point of each growth point on the equivalent sphere surface; The second projection module is configured to expand and map the equivalent sphere surface to a standard two-dimensional parameter domain, and execute preset optimization adjustment operation on the layout of the projection points in the standard two-dimensional parameter domain so as to obtain the coordinates of each projection point on the standard two-dimensional parameter domain after optimization; The parameterization module is configured to reversely calculate final coordinate data of each growing point in the three-dimensional space based on the coordinates of the projection points on the standard two-dimensional parameter domain and the mapping relation from the three-dimensional layered interface to the standard two-dimensional parameter domain; A polygonal cell formation module configured to form a polygonal cell: The growth points on the outer layer interfaces in the two adjacent three-dimensional layered interfaces are used as first nodes on the polygonal cell bodies between the two adjacent three-dimensional layered interfaces, and the growth points on the inner layer interfaces in the two adjacent three-dimensional layered interfaces are used as second nodes on the polygonal cell bodies; the first nodes and the second nodes are connected to form a polygonal cell body positioned between two adjacent three-dimensional layered interfaces, edges formed by connecting a plurality of first nodes or surfaces formed by enclosing a plurality of first nodes on the polygonal cell body are positioned on the same outer layer interface, and edges formed by connecting a plurality of second nodes or surfaces formed by enclosing a plurality of second nodes on the polygonal cell body are positioned on the same inner layer interface.

Description

Porous structure design method and system with closed outer contour Technical Field The application relates to the technical field of structural design, in particular to a porous structure design method and system with a closed outer contour. Background In the fields of additive manufacturing and personalized medicine, there is an increasing demand for components (e.g., bone implants, lightweight heat sinks) having complex shapes and porous structures inside. In the prior art, the design method of the porous structure has the limitations that the traditional regular lattice filling method is difficult to attach to a complex free-form surface and is easy to generate overhang or holes at the boundary, the structure generated based on a random algorithm (such as a random growth method) is natural in shape, but the pore distribution, connectivity and mechanical properties of the structure are unpredictable and difficult to accurately control, the performance design requirement of a load-bearing structure cannot be met, and the method based on three-dimensional image processing (such as CT reconstruction) can reproduce natural pores, but the structure depends on a specific sample, and the active design and optimization of performance driving cannot be realized. In the prior art, for example, CN119494250a discloses a porous structure generation method, which firstly defines parameters of porosity, dimension and the like and randomly distributes pore seed nodes, then iteratively solves a double barrier diffusion equation to simulate random growth and merging processes of pores, and finally generates a porous structure model with connected pores through thresholding and morphological treatment. But the pore morphology is random, the topology is uncontrollable, the deterministic porous lattice structure with programmable geometric and mechanical properties cannot be generated regularly, the programmed precise control on pore gradient, cell size and manufacturing constraint is lacking, and the method is difficult to be directly used for the customized design of engineering components with strict requirements on morphology, performance and manufacturability. Disclosure of Invention The invention aims to provide a porous structure design method and a porous structure design system with a closed outer contour, which partially solve or alleviate the defects in the prior art, can solve the problems of uniform generation, topological continuity and manufacturing constraint integration of a porous structure on a complex curved surface, and realize the structural personalized design and manufacturing integration. In order to solve the technical problems, the invention adopts the following technical scheme: In a first aspect of the present invention, there is provided a porous structure design method having a closed outer contour, comprising the steps of: constructing a three-dimensional model of the target prosthesis; Layering the three-dimensional model from outside to inside based on a preset interval by taking the outer contour of the three-dimensional model as a reference to obtain a plurality of closed three-dimensional layering interfaces, wherein the outer three-dimensional layering interfaces in the two adjacent three-dimensional layering interfaces are outer layer interfaces; Setting a plurality of growth points on each three-dimensional layering interface according to a preset rule; projecting each three-dimensional layered interface and each growth point to a preset equivalent sphere surface to obtain a projection point of each growth point on the equivalent sphere surface; Expanding and mapping the equivalent sphere surface to a standard two-dimensional parameter domain, and executing preset optimization adjustment operation on the layout of the projection points in the standard two-dimensional parameter domain to obtain the coordinates of each projection point on the standard two-dimensional parameter domain after optimization; Based on the coordinates of the projection points on the standard two-dimensional parameter domain and the mapping relation from the three-dimensional layering interface to the standard two-dimensional parameter domain, reversely calculating to obtain final coordinate data of each growth point in the three-dimensional space; polygonal cell formation: The growth points on the outer layer interfaces in the two adjacent three-dimensional layered interfaces are used as first nodes on the polygonal cell bodies between the two adjacent three-dimensional layered interfaces, and the growth points on the inner layer interfaces in the two adjacent three-dimensional layered interfaces are used as second nodes on the polygonal cell bodies; the first nodes and the second nodes are connected to form a polygonal cell body positioned between two adjacent three-dimensional layered interfaces, edges formed by connecting a plurality of first nodes or surfaces formed by enclosing a plurality of first nodes o