Lateral Load–Drift Response and Limit States of Posttensioned Steel Beam-Column Connections: Parametric Study

Abstract

The objective of this study is to identify the significant parameters that influence the lateral load–drift response of steel posttensioned (PT) connections. In particular, the effects of variations in beam section size are included in the study. First, three-dimensional finite-element models are developed to simulate the monotonic lateral load behavior and limit states of PT connections with top-and-seat angles. Full models are developed to capture out-of-plane movement and beam local buckling behavior of PT connections. The analytical response is validated by using two sets of previous experimental studies. By comparing the test and analytical results, damage identification measures are defined for different limit states, such as angle fracture and strand yielding. The established damage identification measures are then used to examine the monotonic lateral load behavior of PT connections. Using a statistical design-of-experiment approach, the relative significance of 16 factors is assessed. These factors include geometry-related and material-related sources of uncertainty. Results demonstrate that beam depth, column height, and posttensioning strand force have large effects (with contributions greater than 15%) on at least one of the response variables (including initial stiffness, the onset of decompression, residual stiffness, and load capacity). Additionally, there is statistical evidence that the beam depth and the beam flange thickness and width influence all the response characteristics.