A Method and Apparatus for Stiffening Structural Connections or "The Bonet Stud and Patch"

Track Code: 

This invention stiffens structural connections in order to prevent the formation or growth of fatigue cracks in structures.


The invention can be immediately applied to steel bridges and other civil infrastructure, preventing the formation or growth of certain fatigue cracks. This will lengthen the operable life of the structure.

How it works: 

The invention transfers loads from one steel member to an adjacent member via a series of structural studs which are encased in low-cost fiber-reinforced polymer composites. Traditional steel doublers are difficult to install, inspect and replace but they bear shear stress loads well. Fiber-reinforced steel composites (FRSC) components are stronger, easier to replace, corrosion-resistant, fatigue-resistant and easier to inspect but respond poorly to the shear stress loads exerted by civil structures. The Bonet Stud transfers the shearing load into bearing load stress, allowing the use of an FRSC patch within the structure.


Application of the Bonet Stud and Patch will allow for longer lasting, and stronger civil structures. Compared to traditional steel doublers, workers and inspectors can easily remove, inspect and replace the Bonet patch.

Why it is better: 

KU testing and study has shown the resulting composite joint to be superior to traditional joints in terms of strength, fatigue resistance, ease of inspection, and reparability. Tests demonstrate no signs of cracking after 4 million fatigue loads on the invention. Traditional steel joints show cracking after 1.2 million cycles.

Other Applications: 

Seismic design, non-welding repair (especially advantageous in explosive environments, some underwater environments, the nuclear power industry and chemical plants).

Licensing Associate: 
Michael Patterson, JD · m.patterson@ku.edu · 785-864-6397
Ronald Barrett
Eric Bonet