AEROSPACE ENGINEERING

Abstract

One of the challenges with the simulation of the mechanical response of composite materials is that their damage mechanisms depend strongly on the material micro- and mesostructures. Homogenized continuum models that describe these mechanisms are extremely mathematically complex, lack generality, and can only be used to fit experimental data. This makes model calibration extremely cumbersome and limits the predictive capability of the model. In reality, the modeling of damage and fracture in composite materials does not have to be complex if the physics of the micro-and mesostructures is simulated explicitly. This is the goal of the Discrete Model for Composites (DM4C), a novel discrete mesoscale modeling framework that simulates the mechanical behavior of UD and textile composites. In DM4C, fibers, groups of fibers, and tows are simulated explicitly as Timoshenko beam elements while the matrix is described by vectorial constitutive laws defined on the facets of a tetrahedral mesh anchored to the nodes of the beam elements. These vectorial laws describe both the elastic and inelastic behavior of the matrix, including the traction-separation laws governing the fracture process and the friction between facets governing the compressive behavior. To demonstrate the predictive capability of the proposed framework, simulations of several typical damage mechanisms in composites will be compared to experimental data such as shear band formation in transverse compression, fiber micro-buckling and kinking in longitudinal compression, and sub-critical matrix microcracking in off-axis layers.

Speaker

Dr. Marco Salviato

Associate professor in the William E. Boeing Department of Aeronautics and Astronautics of the University of Washington. He obtained a Ph.D. in Theoretical and Applied Mechanics in 2013 from the University of Padova. He later joined the Department of Civil and Environmental Engineering at Northwestern University as a postdoctoral scholar (2013-14) and research assistant professor (2014-15). He serves as the director of the UW Advanced Composites Center (ACC) and the FAA-sponsored Advanced Materials in Transport Aircraft Structures (AMTAS) Center of Excellence. He received the ASME Haythornthwaite Young Investigator Award in 2017 and the DSTech Young Composites Researcher Award in 2020. In 2021, he was selected as an NAE Grainger Foundation Frontiers of Engineering Grant awardee. His work has been funded by FAA, NSF, Boeing, AFRL, and DOE.