Failure Analysis: Hurricane Window Defects

Laminated Glass: A glass failure analysis expert witness was engaged to inspect hurricane window defects. These windows were sold to meet the Miami Dade/State of Florida Building Code Requirements for hurricane resistance, and during development of the process, it appears as if these requirements were met. However, the laminating plastic in these windows interacted with the heat and humidity in south Florida. It appears that the laminated windows have a lamination plastic that dissolves and looses adhesion to the glass (please see attached photos). After deterioration these windows are no longer acceptable visually. In addition, it is certain that they will not pass the required code tests.

Window Expert Discusses Metal Clad Wood WIndows

As a result of a window failure analysis performed by a failure analysis expert, several observations were made with respect to metal clad wood windows. The perception is that these windows are almost maintenance free. The outside metal cladding does not need painting, and the wood layer is inside, so it requires minimal maintenance. Numerous window failure analysis has shown that under certain circumstances, water enters through poor seals on the seams of the metal cladding. Once the water enters, the wood swells, and the seam openings worsen. Worse is that the wood cannot dry out because of the metal barrier. In addition, the metal cladding on the windows heat up to 140°F and higher. This is a "composting" environment that causes the wet wood behind the cladding to rot. In the early stages, the window damage is not visible because it is behind the metal cover. Eventually, the wood becomes weak and the window can no longer protect the interior of the building. Often this happens before the home owner is aware that there is a problem.

Coffee Pot Failure Analysis

A failure analysis was performed on a glass coffee press. In this case the glass coffee pot is a 0.085" thick borosilicate glass 3.7" diameter cylinder that is 7" high. It had received a blow on the top rim, and it broke into approximately 10 pieces. Because the pot is a cylinder, the blow from the outside on the rim created tensile stress on the inside of the pot and compressive stress on the outside of the pot. This is reflected in the fracture surface above. The crack traveled faster on the inside half of the glass fracture surface. It finished as twist hackle on the outside half of the glass fracture surface.

Glass Failure Analysis: Windshield

A failure analysis was performed on a light rail windshield failure. In this there was a pop and the operator was showered with glass. The glass failure analysis expert witness determined that there were two leads to the windshield defogger that were in proximity and because they were improperly wired, arcing occurred between them. The arcing generated heat and pressure that caused the glass to crack and spall locally. Upper left is a photograph of the damaged region of the windshield. Upper right is a closeup of the leads that arced. One can see that the lead ends are melted.