CAREER: A Local-Nonlocal Coupling Framework for Tissue Damage in Fluid-Structure Interaction

Lehigh University, Bethlehem PA

Investigators

Abstract

This project aims to develop a new mathematical framework and the corresponding high-performance open source software for addressing fundamental open questions on multiscale and multiphysics modeling of soft tissue damage process, with the ultimate goal of improving the understanding of heart valve damage mechanisms. The resultant framework will have substantial impacts in heart valve operation and research, and will potentially contribute towards more rigorous interventional and surgical procedures. The computational tool and the methodology developed in this project can also be used efficiently in a wide range of physical and biological problems. For the educational component, this project will provide an excellent research and outreach platform for promoting female and under-represented groups in Science, Technology, Engineering and Mathematics (STEM) fields in a range of educational levels from middle school to young researchers post graduate school. These activities include (1) introducing a heart function module in a summer outreach program to expose middle school girls to science and engineering, (2) providing research opportunities for undergraduate students from primarily undergraduate institutions to promote the students' engagement in scientific studies, and (3) organizing an annual high-performance computing (HPC) workshop and a multiscale/multiphysics modeling topical workshop to promote the participation of female students and researchers in the areas of applied mathematics and scientific computing. Technically, a central theme of the research component is the development of a computational approach which models the physically realistic process of heart valve degradation under long-term cyclic hemodynamic loading with the objective of understanding tissue fatigue mechanisms. Emphasis will be placed on modeling the fiber-level tissue damage induced by cyclic hemodynamic loading and its long-term progression. Specifically, the computational domain is composed of three subregions: the fluid (blood) simulated as incompressible Newtonian flow, the fracture thin structure (damaged heart valves) modeled by the nonlocal peridynamic shell theory, and the thin structure (undamaged heart valves and aortic walls) described by a classical hyperelastic shell model. These three subregions will be numerically coupled to each other with proper interface boundary conditions. Novel constitutive models and corresponding numerical schemes will be developed, and new local-nonlocal coupling strategies will also be designed. A powerful computational open source software will be developed, which not only will contribute to advance the knowledge of soft tissue damage, but also will increase the range of capabilities for computer simulation of problems in long-term materials and manufacturing damage progression in general. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.