Deformable Geometry Design with Controlled Mechanical Property Based on 3D Printing

Deformable products exist broadly in different industries. These deformable products undergo deformation to achieve specific mechanical properties. Custom made insoles are applied to redistribute plantar pressure under feet to reduce stress related issues, such as diabetic ulceration. Also there are some other deformable products, i.e. cushioned chairs, custom made running shoes, light weighted space structure and so forth.;The basic mechanical property under all these deformable products is stiffness with respect to deformation. Our research interest is to design these deformable geometries with controlled mechanical properties, and in order to do this, we investigated new design approaches and completed achievements to achieve mechanical property control in different research phases.;First, we explored how to design complex geometries to achieve maximal stiffness in a single material. A PSL (principal stress line) based strategy is studied to design an optimal rigid Michell structure like topology. This Michell structure like topology obtained by PSL strategy is more refined than other approaches. We called this strategy reduction and growth approach.;Second, we studied on how to design geometries to achieve target stiffness with multiple materials. Digital material design is investigated to design target stiffness in a given domain with a soft and a stiff material. Our digital material design method for desired stiffness is predictable and can be interpolated into more levels with higher resolution.;Also we investigated how to apply these N-level digital materials to achieve controlled flexibility skin design. Simulation results for both digital material and flexibility skin design with N-level digital material have been shown and evaluated. A physical experiment was also investigated to verify the simulation results on digital material.;Third, we investigated how to design geometries to achieve target compliance in a fixed topology of structure. A FCF (flexibility contribution factor) based method is provided to achieve the target compliance design of a geometry. This FCF method increases computation efficiency greatly compared to other optimal approaches.;One challenge is how to fabricate these designed geometries with controlled stiffness,since they are either very complex geometries or contain multiple materials.;Fortunately, 3D printing techniques have the unique capabilities to manufacture complex geometries and multiple materials. Nowadays, custom made products by 3D printing are going to main stream. We are expecting our research achievements to be applied with 3D printing and to impact the manufacturing industry.