Nonlinear analysis of compressive behavior of 17-4PH steel structures with large spherical pores built by selective laser melting

Steel porous materials are multifunctional lightweight materials with a great potential in several applications. Their properties are strongly influenced by type, dimension and distribution of pores. Selective laser melting (SLM) is one of the most important additive manufacturing technologies, which allows to properly control the main parameters that affect the behavior of manufactured porous materials. The purpose of this study is to simulate the room temperature compression behavior of steel specimens with large spherical pores built via SLM. Such a construction is a highly innovative manufacturing concept. The numerical simulation covers the whole deformation range undergone by specimens that is up to 80% nominal strain. In this regard, three finite element models of the specimens subjected to uniaxial compression are developed including different levels of detail. The Hollomon model is selected as the constitutive model given in input to the FE simulations. Although experimental tests highlight a highly nonlinear behavior entailing plastic collapse of porous samples, numerical simulations can accurately reproduce experimental results. Modeling issues that may contribute to limit the computational cost of simulations yet preserving good level of accuracy of FE results also are discussed in the article.