Ductility of shear stud
Recently one of our Indian clients asked the question about the reduction of area of shear stud, and he only knows the elongation of shear stud, the two parameters belong to the ductility of shear stud. This post will talk this topic.
The shear studs(also called shear connectors) are used on steel construction building, mainly because the shear studs have better ductility which is a desirable property for structural materials to resist the earthquake. In the ISO13918 standard, it only requires the elongation of shear studs(≥15%), and there is not the requirement for reduction of area, this is the reason why most guys don’t know the parameter. But in the AWS D1.1 standard, the elongation for Type A is 17%(in 2 in.) and 14%(in 5x dia.), for Type B is 20%(in 2 in.) and 15%(in 5x dia.) which is mainly for shear studs. The reduction of area for Type A and Type B both are 5o%.
Ps: If some guys want to know the main standards for shear studs, please see our former post: Comparison of shear connector for main standards
Definition of ductility of shear stud
Ductility is defined as the ability of the shear stud to deform plastically before fracturing. Its measurement is of interest to those conducting shear stud forming processes, to designers/engineers of steel structures, and to those responsible for assessing the quality of the shear stud as it is being produced.
How to measure ductility of shear stud?
There are two parameters: Elongation and reduction of area.
Elongation (%) = 100 x ∆L/Lo
where Lo is the original gage length.
Reduction of Area (%) = 100 x (Ao – Af)/Ao
where Ao is the original cross-sectional area
Ps: If some guys don’t know about the elongation of shear stud, please see our post: How to test mechanical properties of shear stud?
To help to understand the reduction of area of shear stud, please see the image.
In the testing sample,
reduction of area=100*(A0-Af)/A0=100*(πR2-πr2)/πR2=100*(R2-r2)/R2=100*(0.42-0.2652)/0.42=56