Experimental and numerical study of microscale fractures - Application to brittle fracture in thin films and ductile fracture in metals

Fracture toughness is crucial for engineering materials' reliability across industries. This thesis explores brittle fracture in thin films and ductile fracture in copper single crystals. Barium titanate thin films on silicon substrates are examined using micro-indentation and electron microscopy, revealing crack propagation and morphology. Stress-based and energy-based approaches quantify fracture resistance, with numerical modeling for validation. Ductile fracture focuses on void coalescence in copper, modeled via crystal plasticity finite element methods. The study investigates loading parameters' effects, including stress triaxiality and Lode parameter, on fracture processes and ultimate failure strain.