Development of Nonlinear FEA Method for 3D-Printed Polymeric Porous Structures

Three dimensional printing technology has widely been utilized to construct a variety of complex biomimetic structures. A target structure is designed using 3D-CAD and then the CAD data is sent to the controlling unit of a 3D-printing machine to fabricate a corresponding real structure. Recently, FEA installed into 3D-CAD can be used to assess their structural integrity of the designed structures. However, it is still difficult to analyze the nonlinear mechanical responses using FEA. The aim of the present study is to develop a nonlinear FEA method to characterize the elastic-plastic deformation behaviors along with micro-damage formations of 3D-printed polymeric porous structures. It was found that the proposed FEA method can reasonably be used to predict the nonlinear behaviors of two different types of 3D-printed porous structures under compressive loading. Mechanical properties such as stiffness, fracture energy and strength were also well predicted by FEA. The micro-fracture processes of the real structures were well characterized by the damage models with FEA including the tensile cracking with the maximum principal stress criterion and the compressive crushing with the minimum principal strain criterion.