Increasing use of adhesively bonded joints (ABJs) and polymer nanoclay composites (PNCs) in modern vehicles and other industrial sectors has deeply shaped the design and manufacturing of advanced materials and structures for better mechanical stiffness, durability, and fracture toughness. (1) A nonlinear fracture model is formulated for accurately extracting the fracture toughness of ABJs with large plastic deformations and springback and further validated by ABJ fracture data available in the literature. (2) Cohesive zone model (CZM) is integrated into finite element method (FEM) to simulate the debonding process of ABJs at varying adhesive layer geometries and material properties. (3) CZM is further utilized for exploring the failure mechanisms of PNCs under external loading at varying PNC geometries and material properties. The present studies can be useful for effective and accurate data reduction and further improving the design and manufacturing of ABJs and PNCs with tailorable mechanical properties.