An efficient axial-flexure-shear fiber beam model for dynamic analyses of beam-column framed structural systems under impact loading

Impact loadings induced by collisions from an external impacting object (e.g. a vessel, a vehicle) severely threaten the safety of our infrastructural systems such as bridges and buildings. It is therefore critical to develop effective strategies to quantify the impact loadings and dynamic structural responses so that the safety of structures can be pre-estimated. Although the extensively used finite-element simulations can generally provide realistic predictions of impact forces and dynamic responses of structures subjected to vessel or vehicle collisions, they are often computationally expensive. Therefore, the development of computationally efficient simplified impact models using macro-elements has drawn the attention of many researchers. This paper aims to develop a more general-purpose simplified impact model for dynamic analyses of beam-column framed structural systems under impact loading with consideration of shear effects in beam-column members. The well-known Timoshenko beam theory is adopted to develop a fiber beam model that couples the axial, flexural and shear actions in beam-column members at the fiber and material level. A parametric study is then conducted to thoroughly assess the numerical performance of the proposed simplified impact model using several sets of circular columns with different cross-section diameters and height-diameter ratios under the impact from a barge vessel, the complex finite-element model of which was developed and validated by the author previously. The study indicates that the proposed simplified impact model using the axial-flexure-shear fiber beam model enables a sufficiently accurate prediction of the time-histories of impact forces and dynamic responses of both flexure-dominant high columns and shear-dominant short columns under different impact scenarios.

Automated summary

This paper aims to develop a simplified impact model for dynamic analyses of beam-column framed structural systems with consideration of shear effects. The proposed model, utilizing a fiber beam model, is able to accurately predict the impact forces and dynamic responses of different columns under various impact scenarios.