Carbon Mast Structural Damage Detection Using Ultrasonic NDT Method

Abstract

Glass and carbon fibers as materials have become the primary choice in the construction of smaller vessels. The advantages of these materials are good mechanical properties, they are relatively light materials that today anyone with a little knowledge can handle and also, financially speaking, they are materials that are affordable to almost everyone. One of the disadvantages is that composite materials are not homogeneous. This would mean that irregularities can be observed in the cross section of the laminate of such composite vessel or equipment. These irregularities are usually negligible because they simply belong to the property of composite materials. The problem arises when imperfections are caused by human factors or the action of some external force such as residual air in the laminate or delamination. Such imperfections during navigation can cause catastrophic damage. Although visible damage may seem small, it is very likely that there is much greater damage to the laminate that is not visible because it is located somewhere between the layers of fibers. Various methods exist for detecting such damage and imperfections, which can be invasive or non-invasive. The focus of this paper is on detecting the magnitude of damage in the laminate of the carbon mast of a racing sailboat Melges 32 using a non-invasive ultrasonic testing method. The Avenger EZ device was used for testing only.