Numerical simulation of failure mechanism in screw anchors under static tension

Abstract

Concrete screw anchors under tension commonly fail in a combined (pullout and concrete breakout) mode; however, currently, there is no mechanistic model to predict the load in this mode. Finite element models of screw anchors can help understand the mechanism of the combined mode and predict the ultimate strength in this mode ( Ncomb). In this study, finite element models were developed and validated by 37 tests of screw anchors in three different diameters ( d) and two effective embedment depths ( hef) per diameter. The finite element models were used to identify the combined failure mode and to compare with the experimental load–displacement curves and Ncomb. An additional 119 simulations including variations of d, hef, and concrete compressive strength [Formula: see text] were generated. Based on the results, Ncombwas found significantly related to [Formula: see text], [Formula: see text], and d0.35. A prediction model for Ncombwas developed which showed an overall good fit using a total of 93 experimental data.