Mesoscopic Simulation Method of Joint Interface Layer of Prefabricated UHPC Structures

Wet joints are commonly applied in the prefabricated UHPC structures, where the bonding performance of joint interfaces is critical to structural safety. Generally, it is neither economical nor efficient to study the performance of the joint interface through experiments, and the traditional simulation ways have the disadvantage of unclear failure mechanism. Based on the sinusoidal function, an effective two-dimensional mesoscopic simulation method is proposed to characterize the random rough interface of UHPC. Then, the geometry model of the method is realized through a custom program. In addition, grounded in the three-dimensional random fiber distribution code, a two-dimensional random fiber delivery and quantity control method is developed. Further, considering the effect of fiber random distribution, random rough interface and interface layer thickness, the mesoscopic numerical model’s stability is analyzed by finite element method. Finally, the offered mesoscopic simulation methods are verified to be feasible through the splitting test results for three interface types: untreated, chiseled and grooved. The results show that the random distribution of fibers and the randomness of the rough interface have little effect on the bonding performance. Combined with simulation accuracy and stability, a virtual thickness of 1.0 mm for the interfacial layer is recommended. Moreover, the proposed mesoscopic simulation method can observe the stress and damage evolution process of joint interface. According to the comparison between numerical and experimental results, this method can be employed to study the bonding performance of UHPC joint interfaces with a recommended interface layer performance reduction coefficient of 0.8.