Mixed-mode I + II fracture characterization of cortical bone tissue is addressed in this work. The
mixed-mode bending test was used to impose different mode ratios. An equivalent crack length
data reduction method was considered to obtain the strain energy release rate components. Crack
opening and shear displacements were measured by means of digital image correlation. These
quantities were then integrated to propose a direct evaluation of cohesive laws. The components
of the cohesive laws for each mixed-mode loading were obtained by the uncoupled and Hogberg ¨ ’s
methods. The later provided consistent evolution of strain energy release rate and peak stresses
components in function of mode-ratio, revealing its appropriateness regarding the fracture
characterization of cortical bone under mixed-mode I + II loading.The first and second author acknowledges the Portuguese Foundation for Science and Technology, under the project UIDB/04033/2020. The third and fifth authors acknowledge the ‘Laboratorio' Associado de Energia, Transportes e Aeronautica’ (LAETA) for the financial support by the project UID/EMS/50022/2019 and the financing of FCT/MCTES through national funds (PIDDAC) and UIDB/00667/2020 (UNIDEMI). The fourth author acknowledges the Portuguese Foundation for Science and Technology, under the project PTDC/EME-SIS/28225/2017
