Shear strength damage model and damage removal FE modeling of stud shear connectors embedded in UHPC

Abstract

The study conducted a series of push-out tests to study the shear strength of studs as shear connectors in steel-UHPC (ultra high-performance concrete) composite structures. The damage removal modeling was developed and utilized to simulate stud damage caused by welding defects, concrete cracking, and lifting effects. The study investigated the impact of stud damage on the static performance and shear strength of studs. Results indicated that when the root area of the stud was damaged, the shear strength and stiffness of the stud decreased with the damage degree. When the stud root was damaged within 5%h (h is the height of stud shank), it had a significant effect on the shear strength of the stud. Damage outside the 5%h range of the stud root had no significant effect on the shear strength of the stud. And a shear strength damage model was firstly proposed to reveal the damage mechanism of studs. A reduction factor K was proposed to account for the loss in shear strength caused by stud damage. Two methods for calculating K, namely the area reduction method and the equivalent area method, were developed. The calculated values of shear strength considering stud damage were obtained and verified by comparing the calculated values with the test results. The proposed method offers a better prediction of shear strength for damaged studs in UHPC.