## 1 Introduction  
Additive manufacturing (AM) has recently emerged in the past two decades. It provides engineers with unparalleled design freedom, allowing them to build complex components without the need for specialized tools and reducing the cost of small-scale assembly methods [1]. Even the most complex CAD models with the necessary functionality may be manufactured, while this would be almost impossible with conventional manufacturing processes. The purpose of the AM process is to generate materials layer by layer [2], depending on the feedstock form (powders vs. wires) [3], feeding method (powder bed vs. blowing powder), energy source (Laser vs. Electron Beam), and materials (Titanium alloy, aluminum alloy, stainless steel, polymers, etc.). AM processes are offering new design flexibility for optimization techniques that are not limited by conventional production constraints [4]. Furthermore, the design freedom provided by AM techniques can result in a strength-to-weight ratio of up to 50%. Among the advantages of additive manufacturing is the high customizability of to-be-created components [5], lightweight components [6], less material waste, the possibility to mix varied technologies, and the simultaneous use of many materials to build a single product. Due to their high strength-to-weight ratio [7], AM components are widely utilized in the aerospace and automotive industries as well as in the biomedical [8] and construction industries. Continuous innovations and improvements in AM have also made it an indispensable technology in sectors like building and orthodntics [9]. Other improvements to bio-based materials and their mechanical, thermal, and chemical properties make it possible for AM to make parts that are long-lasting and environment friendly [10]. The Powder Bed Fusion (PBF) processes facilitate the construction of intricate lattice structures with specific physio-mechanical characteristics [11]. AM has made it easier and more productive to manufacture differently shaped structures with complicated geometries. These structures have significant uses in a variety of scientific domains, including biological and structural applications [12]. They are often encountered in several natural systems, such as the exoskeletons of beetles, the wings of butterflies, and other biological membranes [13]. Due to several limitations, the standard manufacturing technique cannot be used to create these structures due to their very complicated design and production process. Due to its adequate and other mechanical qualities, the solid material structure is primarily employed in early industrial structural design. Although the solid material structure satisfies the design criteria to a considerable degree, it has several defects, including material waste, an inflexible design, a massive volume, and manufacturing challenges [14]. In addition, technological and scientific advancements have increased the demand for structural qualities. Currently, structural design in the industry places more emphasis on lightweight and performance. With the help of cellular structures, scientists can make and do things with low-cost, high-performance scientific materials [15]. Fatigue is the most common failure mode for AM materials and structural components. Indeed, a crack can be caused as a result of it. In cyclic loading situations, the applied stress might be uniaxial, biaxial, torsional, or fracture initiation and propagation far below the material's yield strength [16]. These stresses are often associated with elastic deformation and not plastic deformation. Compared to their wrought counterparts, AM materials have a lower fatigue life. A shorter fatigue life may be attributed to factors such as flaws, residual stress, surface finish, geometry, size, layer orientation, and heat treatment [17]. The unique and complicated microstructure of AM alloys is one of the major factors in their reduced fatigue life.