Enhanced Numerical Simulation and Experimental Validation of Dam Gate Trunnion Rod Anchorage Systems Under Varied Pre-Tensioning Conditions

Abstract

This research presents a comprehensive Finite Element Analysis (FEA) approach to verify the testing configuration for trunnion rod anchorage assemblies used in dam gates, considering their relevant in-situ conditions. A substantial number of Finite Element (FE) models were constructed using Abaqus/CAE 2023, focusing on the effects of varying pre-tension levels and potential failure modes of trunnion rods. One hundred ninety-seven distinct models were developed, each capturing various rod failure configurations and pre-tensioning scenarios, while consistently maintaining the geometric, mesh, and assembly configurations across the different test cases. To enhance efficiency and ensure consistent testing across a wide range of configurations, a Python script was created to automate the model generation process. The resulting test plan comprised 57 configurations at a pre-stressing level of 15%, in addition to 35 configurations corresponding to pre-stressing levels of 30%, 40%, 50%, and 60% of the Guaranteed Ultimate Tensile Strength. A comparative analysis between the FEA simulations and experimental laboratory tests revealed a mean absolute percentage difference of 6.86% for the initial post-tension levels. The final post-tension levels obtained from the FEA simulations showed a mean absolute percentage difference of 10.99% compared to the laboratory results. The impact of the applied load is more pronounced at lower post-tension levels, particularly at 15%. In contrast, at a 60% posttension level, the influence of the applied actuator load appears minimal compared to the significant effects noted at the 15% post-tension level. The most substantial differences in tension levels between the laboratory testing and the FEA models primarily occur at the 15% pre-stressing level. These results confirm the reliability of the FEA models in predicting the structural behavior of trunnion rod anchorage assemblies, paving the way for future assessments of the remaining life of these assemblies.