Abstract
The high-fidelity Metal Additive Manufacturing (MAM) processes promote the development of complex lattice structure designs with tailored physical and mechanical properties. Particularly, the unique characteristics of the Selective Laser Melting (SLM) lattice structures make them desirable in many leading application areas. Nevertheless, the optimum lattice structure for a particular application requires extensive research work starting from the early design phase to the implementation. Therefore, firstly an overview of the various lattice’s designs, properties, performance, and defects was provided. Moreover, a review of the numerical methods developed specifically to analyze the mechanical behavior of lattice structures is presented. Secondly, a new type of lattice based on a circular unit cell was developed and a performance comparison with other types was accomplished. The new circular cell exhibits a relatively high load-bearing capability with low stiffness, and it demonstrates a significant stress recovery upon the collapse of layers making it an ideal candidate for shock-absorption applications. Thirdly, an element deletion algorithm based on the fracture locus of material is developed and implemented into open-source software to determine the onset of failure, crack nucleation, and fracture growth. The code was tested on the circular lattice and proved reliable in predicting the onset and the initial fracture region however with computational issues that prevent the visualization of the complete fracture. Accordingly, a new approach is created in the form of a phenomenological model which is capable of predicting the compressive stress-strain curves of lattices that exhibit crushing failure mechanisms based on their relative densities alone. The model is used to drastically reduce the time and cost needed during the design phase and tailor the lattice structure properties to serve a specific application. Finally, the superior properties of lattice structures are employed to generate a new mandibular reconstruction plate with a better survival rate. The preliminary mechanical and biocompatibility tests showed that latticed plates promote osseointegration while maintaining mechanical integrity. Overall, this thesis covers the whole process from design to application while providing the necessary tools to render it easier, more comprehensible, and most importantly achievable.