Energy efficiency presents a paramount societal challenge, necessitating advanced lightweight materials for enhanced performance and fuel economy. Understanding the mechanical properties of these materials, rooted in their atomistic origins and microstructure across multiple length scales, is pivotal. Our work leverages an advanced multiscale modeling framework to unveil dynamic deformation and failure processes, establishing a fundamental grasp of structure- property relationships to expedite novel material design. In this seminar, I will showcase our recent endeavors in the development and application of theoretical and computational methodologies spanning from the atomic scale to the mesoscale and continuum levels. Through atomistic modeling, we have elucidated the pivotal role of phase transformation in deformation twinning across diverse metals and alloys. Our mesoscale phase-field dislocation dynamics model enables the analysis and prediction of multiscale dislocation phenomena in metals. At the continuum level, we have introduced a phase-field fracture model that illustrates the influence of material microstructure on crack nucleation and propagation within polycrystalline zirconia.