In collaboration with Dr. Gerard Ateshian at Columbia University, the Weiss laboratory develops, maintains and supports FEBio (Finite Elements for Biomechanics and Biophysics,, an open-source finite element software package for computational biomechanics and biophysics. As of 2023, there are over 16,500 registered users and the software has been downloaded over 77,000 times. This R01 project has been funded by NIH/NIGMS since 2007. This has provided the opportunity for us to serve the biomechanics research community by developing new computational algorithms and methodologies to meet their research needs, and to document, distribute and support the software.

Our research in computational biomechanics focuses on the use of the finite element method to examine the mechanics of soft and hard tissues. We have developed techniques to build subject-specific finite element models of soft and hard tissues directly from medical image data such as CT, MRI, OCT or microscopy images.

We have also developed constitutitve models and finite element implementations that capture the nonlinear, anisotropic and viscoelastic properties of materials such as ligament, tendon, cartilage and meniscus. Our last focus has been on capturing boundary conditions in numerical simulations that are unique to biomechanics such as residual/initial stress and position-dependent anisotropy. The techniques have been applied to the study of knee mechanics, shoulder ligament mechanics, cartilage defects, and the hip.