The shear stiffness of headed-stud shear connectors has no unified definition due to the nonlinear characteristics of
its load-slip relationship. A unified framework was firstly adopted to develop a general expression of shear load-slip equation for
headed-stud shear connectors varying in a large parameter range based on both force and energy balance. The pre- and postyield shear stiffness were then determined through bilinear idealization of proposed shear load-slip equation. An updated and
carefully selected push-out test database of 157 stud shear connectors, conducting on studs 13~30mm in diameter and on
concretes 30~180 MPa in cubic compressive strength, was used for model regression and sensitivity analysis of shear stiffness.
An empirical calculation model was also established for the stud shear stiffness. Compared with the previous models through
statistical analysis, the proposed model demonstrates a better performance to predict the shear load-slip response and stiffness of
the stud shear connectors.
