Buckling Analysis of Cracked Column Structures and Piezoelectric-based Repair and Enhancement of Axial Load Capacity

Decreased flexural and buckling capacity of composite structures due to the development of fatigue cracks is a serious issue in a variety of fields. This paper discusses the buckling capacity and piezoelectric material enhancement of cracked column structures. A model of the rotational discontinuity at the crack location is used to develop analytical buckling solutions and the effect of crack location and intensity on the buckling capacity of the damaged columns is investigated. Small piezoelectric patches are employed to induce local moments to compensate for the decreased buckling capacity of column structures, using a mechanical model coupled with piezoelectric strain-voltage relations. The voltages required to enhance the buckling capacity are analytically determined and the general relationship between crack location and voltage developed. The primary advantage of the piezoelectric-based repair approach presented is the ability to use a single small patch, with different applied voltages, to repair cracks of a wide variety of depths, intensities and locations passive design solutions would require custom designs to restore the axial load capacity for each case.