Under the certain strain path, granular materials may exhibit non-localized failure mode corresponding to an abrupt occurrence of failure with the stress states within the Mohr-Coulomb yielding surface. Using the discrete element method (DEM), mechanical properties of granular material with different rolling friction coefficients are examined under proportional strain loading paths. For particle assemblies of different densities, looser assemblies tend to have diffuse failure, which qualifies Hill’s second-order work criterion. A contact model considering rolling friction is adopted in DEM analysis. By changing the rolling friction coefficient, micro-macro mechanical properties of particle assembly are studied under a specific proportional strain-loading path. The enhancement of particle rolling resistance reduces the likelihood of diffuse failure. At the macro level, stress path changes from strain softening to strain hardening as the rolling friction coefficient increases, and the looser particle assembly exhibits the similar mechanical behaviours as the denser one. The micro-structure shows the corresponding mechanism of action. As the rolling friction coefficient increases, the angular velocities of particles and their distribution will be well controlled. Although the coordination number decreases, the contact forces are enhanced, and the instabilities and anisotropies of the force chain distribution can be improved in the system. All the microscopic parameters manifest a stable structure, which can resist the increasing load, thus the specimen will not form a loose contact state and diffuse failure will not occur.