Twisted fiber pullout from UHPC: A computational study

A highly detailed computational model is developed to simulate the behavior of twisted steel fiber pullout from ultra-high-performance concrete (UHPC). The model considers the effect of fiber-matrix interfacial behavior and material inelasticity. It is shown that the model is capable of reproducing key experimental observations including the ability of twisted fibers to exhibit pseudo-plastic behavior for slip values up to 80%-90% of a fiber’s embedded length. It is also shown that the maximum pullout decreases with increasing pitch and that fibers with triangular cross-section hae a somewhat larger ability to dissipate energy than fibers with other cross-sectional shapes.