Comparison of evolving gradient damage formulations with different activity functions

Abstract In the paper, two existing upgrades of gradient damage model for simulations cracking in concrete are compared. The theory is made nonlocal via a enhancement to overcome mesh dependence simulation results. implicit with an averaging equation, where internal length parameter assumed as constant during strain softening analysis, gives unrealistically broadened zones. scalar can be improved function scale, so evolution activity postulated localization process. Two different modifications equation and respective evolving formulations presented. Different functions tested see whether formation too wide zone still occurs. Activating or localizing character influence introduced impact both approaches on numerical results shown paper. aforementioned variants implemented examined using benchmarks tension bar bending cantilever beam.