InSIS Webinar Series – 2023 – Fracture and size effect in the compressive failure of fiber reinforced composites

Abstract:

Continuous fiber reinforced composites predominantly fail by the formation and propagation of a fiber kink band when subjected to compression along the fibers. While the underlying physical micro-mechanisms have been widely analyzed, various aspects still lack a complete understanding, such as 3D constitutive modeling and the strength size effect. In this presentation we will first discuss the various kinds of size effects exhibited by the general class of quasi-brittle materials, and the scaling laws which describe them. Next, we will discuss experimental evidence for the applicability of these laws to compressive failure of fiber composites. This is crucial for understanding how to apply lab-scale fracture properties to design real world structures. Next, we will discuss a novel 3D constitutive model developed for the kink band failures in composites. The model is developed within the general class of “microplane” constitutive models. These are two-scale models, widely applied to capture complex failure behaviors of heterogenous materials at the macro-scale, by formulating intuitive and simple damage laws at the micro-scale. The effectiveness of this approach to capture the kink band micro-mechanisms will be demonstrated. In conclusion, we will discuss both the utility and challenges of applying the experimental findings and the modeling capabilities to design real world structural applications.

Bio-data of speaker:

Prof. Kedar Kirane is an assistant professor of Mechanical Engineering at Stony Brook University, New York. His research focuses on characterizing, understanding, and predicting the fracturing and scaling behavior of various conventional and advanced composite materials. These include brittle materials, fiber reinforced composites, polymer nanocomposites, geological and cementitious materials, and soft materials. His research combines experimental, computational, and theoretical approaches. The overarching goal is to develop reliable predictive capabilities and sound scientific bases for safe structural designs in various engineering applications. Prof. Kirane obtained his Ph.D. in 2014 from Northwestern University and joined the Mechanical Engineering faculty at Stony Brook University in Sept 2017. He also holds an M.S. degree from the Ohio State University (2007) and a B.S from the University of Pune, India (2004), both in mechanical engineering. Prior to joining Stony Brook, Prof. Kirane worked in industry, as a finite element analyst at Goodyear Tire & Rubber Co and later as a senior research engineer at ExxonMobil Corp. His research is supported by DOD ARO, DOD ONR, and ASME. He is the recipient of the 2020 Orr Early Career Award by ASME’s Materials Division, the 2019 DOD ARO Young Investigator Award, and the 2018 Haythornthwaite Research Initiation Grant by ASME’s Applied Mechanics Division.

Organized by:

InSIS and Center for Structural Integrity of Safety Critical Systems, IIT Madras