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 ( f ′ c ) were generated. Based on the results, Ncomb was found significantly related to h ef 1 . 3 , f ′ c , and d0.35. A prediction model for Ncomb was developed which showed an overall good fit using a total of 93 experimental data.

中文翻译：

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静拉下螺旋锚破坏机理的数值模拟

受拉混凝土螺钉锚通常在组合（拔出和混凝土突破）模式下失效；但是，目前还没有机械模型来预测这种模式下的负载。螺旋锚栓的有限元模型有助于理解组合模态的机理并预测该模态下的极限强度（Ncomb）。在这项研究中，通过对三种不同直径 (d) 和每个直径的两个有效嵌入深度 (hef) 的螺钉锚栓进行 37 次测试，开发并验证了有限元模型。有限元模型用于识别组合失效模式，并与实验载荷-位移曲线和 Ncomb 进行比较。生成了另外 119 个模拟，包括 d、hef 和混凝土抗压强度 (f′c) 的变化。基于结果，发现Ncomb与h ef 1 显着相关。3、f′c 和d0.35。使用总共 93 个实验数据开发了 Ncomb 的预测模型，该模型显示整体良好的拟合。