COMPRESSIVE FAILURE AND SIZE EFFECT IN COMPOSITE MATERIALS
Fiber reinforced composites under compression predominantly fail by the formation and propagation of fiber kink bands. This is a critical failure mode for composites with complex underlying micro-mechanisms such as matrix micro-cracking and fiber micro-buckling. We are developing multiscale microplane models to capture these and also analyze and predict the ensuing size dependence of the failure loads. Additionally we are also investigating novel experimental techniques to characterize the failure behavior and size effects under compressive loads.
Relevant publications:
1. J. Xue and K. Kirane (2022) “Cylindrical microplane model for compressive kink band failures and combined friction/inelasticity in fiber composites II: Analyses” Composite Structures 291, 115589, https://doi.org/10.1016/j.compstruct.2022.115589
2. J. Xue and K. Kirane (2021) “Size effect in the transverse compressive strength of composites analyzed by the fixed crack model” ASCE Journal of Engineering Mechanics 147(10), 04021074.
3. D. Deland, Z. Zhang and K. Kirane (2020) “Biaxial flexural failure of woven composite plates investigated by the ring on ring bending test” Thin-Walled Structures, 148, 106585
MECHANISM BASED MULTI-SCALE CONSTITUTIVE MODEL FOR FIBER REINFORCED COMPOSITES
Fiber reinforced composites are heterogeneous materials that exhibit a wide range of failure mechanisms depending on the loading condition. So failure prediction under multi-axial loads is highly complex since it occurs via the combination of a variety of mechanisms such as fiber breaking, matrix micro-cracking, fiber kink bands etc. We are tackling this challenge by developing a mechanism-based, constitutive model within the framework of the microplane modeling theory.
1. J. Xue and K. Kirane (2022) “Cylindrical microplane model for compressive kink band failures and combined friction/inelasticity in fiber composites I: Formulation” Composite Structures 289, 115382, https://doi.org/10.1016/j.compstruct.2022.115382
2. Kirane, K., Salviato, M., Bažant, Z.P. (2016). “Microplane-Triad model for elastic and fracturing behavior of woven composites.” Journal of Applied Mechanics 83 (4), 041006.
CONTINUUM DAMAGE MODELING OF DYNAMIC FRACTURE
We are investigating continuum scale modeling approaches for crack branching and damage mechanism transitions that occur during dynamic fracture of brittle and quasi-brittle materials. Specifically, the aim is to understand the numerical considerations that underpin objective and accurate predictions in this regard, and analyze the role played by localization limiters such as the crack band model, and material rate dependence.
Relevant publications:
1. T. Abdullah and K. Kirane (2022) “Strain rate dependence of the mesh objectivity in dynamic fracture analyses with the crack band model” Engineering Fracture Mechanics, 108501
2. T. Abdullah and K. Kirane (2021) “Continuum damage modeling of dynamic crack velocity, branching, and energy dissipation in brittle materials” International Journal of Fracture, 229(1), 15-37
FAILURE AND SCALING OF SOFT MATERIALS AND COMPOSITES
Soft materials have a wide range of application ranging from tires and biomedicine to soft robotics. We are investigating their failure behavior (quasi-static/dynamic), size scaling, and adhesion. Other recent interests include the numerical modeling of cutting and penetration of soft deformable materials.
Relevant publications:
1. K. Kirane and S. Bhatia (2022). “Structure Property Relationships for the Mechanical Behavior of Rubber Graphene Nanocomposites” – in Graphene-Rubber Nanocomposites: Fundamentals to Applications, Taylor & Francis CRC Publishers (accepted, in press)
2. K. Gonzalez, J. Xue, A. Chu and K. Kirane (2020) “Fracture and energetic strength scaling of soft, brittle and weakly nonlinear elastomers” Journal of Applied Mechanics, 87(4): 041009
3. M. Redzematovic and K. Kirane (2021) “Homogenization of the Mooney-Rivlin coefficients of graphene based soft sandwich nanocomposites” Mechanics of Soft Materials 3, 6.
SMALL SCALE FRACTURE OF SILICA
We are pursuing a fundamental understanding of silica failure at molecular length-scales, by employing molecular modeling techniques. Specific interests include effects of size and environment (temperature, pressure etc.) on the failure behavior, stress corrosion cracking, and creep.
Relevant publications
1. J. Park and K. Kirane (2021) “Transitional flaw size sensitivity of amorphous silica nanostructures analyzed by ReaxFF/SiO based molecular dynamics” Journal of Applied Physics, 129 (17), 175103
ADHESION, FRACTURE AND SCALING OF POLYMERS AND NANOCOMPOSITES
We are studying a variety of interesting and unexplored effects of nano-reinforcement (e.g. carbon nanotubes, graphene) on the mechanical properties of polymers. We are also interested in the fracturing and scaling behavior of polymers and 3D printed materials.
Relevant publications
1. J. Menjivar and K. Kirane (2020) “Surfactant assisted dispersion of MWCNT’s in epoxy nanocomposites and adhesion with Aluminum” Polymer Testing, 82, 106308
2. A. Nurizada and K. Kirane (2020) “Induced anisotropy in the fracturing behavior of 3D printed parts analyzed by the size effect method” Engineering Fracture Mechanics 239, 107304
We gratefully acknowledge financial support from our research sponsors
