This Engineering Research Initiation (ERI) project will fund research that investigates the nonlinear behavior of slender beams with localized geometric variations, such as varying curvature, which have the potential to program and tune their mechanical properties. Beams are commonly used in structural systems due to their ability to efficiently distribute loads, and for decades, beam design has primarily focused on global geometric variations to meet key criteria like stiffness, strength, and critical load. However, the vast potential of localized geometric changes has been largely unexplored. This research will attempt to elucidate how localized curvatures influence the nonlinear behavior of beams, providing insights that can drive the development of innovative lightweight structures with tailored mechanical behaviors for applications in biomedical devices, metamaterials, aerospace, robotics, and civil infrastructure. This work looks to address the national need for next-generation lightweight structures that fully utilize material potential. In addition, the project seeks to provide valuable educational opportunities, including the training of graduate and undergraduate students and outreach activities for K-12 students. The objective of this project is to develop a hybrid high-order nonlinear beam model that integrates beam-scale and cross-sectional models to capture large deformations in beam-type structures with arbitrary initial shapes. The research will focus on tw