Wine Bottle Failure Analysis

Glass Failure Analysis Expert Witness Performs Wine Bottle Failure Analysis. In this product liability case the user was injured as the cork was being extracted. The glass failure expert witness performed a glass failure analysis and determined that the bottle failure initiated at the very top of the bottle. Thus, the cork screw could not have caused the damage that initiated the failure. Unopened bottles from the same case were examined, and it was discovered that the rod that pushed the cork in was very close to the glass in three of the four bottles that were examined. This indicates that the failed bottle was damaged during the corking operation. In addition, the forces used to extract the cork drove the pre-existing crack to failure. The photograph on the upper left is of the failed bottle top. In this photo the origin and crack travel direction are indicated. Upper right is a top down photo of a cork from one of the unopened bottles. The impression made in the cork is from the rod that pushed the compressed cork into the bottle. One can see from the impression that the rod was not centered. This indicates that the subject bottle failed due to corking damage. This is a manufacturing defect.

Glass Failure Analysis Expert Examines Failed Champagne Bottle

Glass failure analysis expert performed a root cause failure analysis on a exploding champagne bottle. The user claimed that the bottle exploded when she was using her thumbs to remove the cork. Examination of the bottle revealed a horizontal crush point. This damage was severe and would not have survived the corking operation at the winery. Thus this damage was caused by a tool when it was used by the injured party to remove the cork. There was an indication that this bottle had been in the freezer prior to the accident. Thus, there was little or no internal pressure to aid in the removal of the cork. Thus a tool was used, and this caused the failure. The photograph on the upper left is of the salvaged pieces of the exploding champagne bottle. The photograph on the upper right is of the fracture initiation point and the failure origin.

Glass Failure AnalysisExpert Examines Cracked Automobile Windshield

Glass expert performs a glass failure analysis on a cracked automobile windshield. Records show that the windshields on this particular make and model of automobile are cracking at a very high rate. The windshield shown here is the third replacement in two years. In this case, glass failure analysis shows that the crack started at an impact point two inches below the top of the windshield. Initially the windshield crack was driven by bending stresses. Later it was driven by thermally generated stresses (caused the crack to curve). Factors that are of concern are the glass thickness, mounting (i.e. bending) stresses in the windshield, perpendicularity of the windshield and glass lamination stresses. Eventhough the failure was caused by an impact point; this damage should not have caused a large crack to form. The upper left photo is an overview of the crack. In the center is a close up of the impact point. Upper right is a 40X photomicrograph of the crack origon.

Tempered Glass Expert Describes Failure Origin for Tempered Glass

Glass failure analysis expert demonstrates how to locate the origin of a tempered glass failure. Glass failure analysis of a tempered glass piece is difficult (if not impossible) because tempered glass fracture results in many small pieces. In many cases the glass failure falls apart and there is no pattern left to trace to the origin. Thephotograph above provides a pattern that can be a useful tool for locating the general location of the failure origion of a partial crack pattern. In the above example a glass expert taped a tempered glass pickup truck rear window with transparent tape and impacted it with a simulated human head. The resulting crack pattern is preserved. The impact point is the center of a "web" of cracks. The predominant pattern is a series of "spokes" eminating from the impact point which is also the failure origin.

Glass Failure Analysis Expert Discusses Metal Clad Wood WIndows

Glass failure expert re-visits the window reliability of metal clad wood windows. Recently, numerous entities are suing various window manufacturers because of premature window failure (i.e. poor window reliability) of various brands of metal clad wood windows. These window failures are not manufacturer dependant; they are a result of the fact that these are metal clad wood windows. At issue is the fact that water can breach the caulk seal of the metal cladding and saturate the wood. This inturn causes the wood to expand and compromise these seals further. The trapped water cannot escape and as the window heats in the sun, the wood rot occurs (the wood composts), and the window structural integity is compromised (see the photographs above). A degraded window cannot prevent water intrusion. This window damage can happen rapidly (less than 3 to 5 years), and it is hidden from view by the metal cladding. Window reliability is poor and the chance for significant storm damage to a home is very high

Glass Bottle Failure Analysis

Glass failure analysis expert performed a root cause failure analysis on a bottle failure. The cap on this bottle had not been removed. The failure analysis revealed a manufacturing defect on the bottle interior. On the upper left photo is a 30X photomicrograph of a portion of the origin on the fracture surface. The arrows show the travel direction of the crack exiting the origin. On the upper right is a 30X photonicrograph of the origin as it appears on the interior surface of the bottle. There is a "chip" associated with the origin; therefore, this is a product defect on the bottle interior.

Botle Manufacturing Defect

Glass failure analysis expert performs a root cause failure analysis on a bottle failure. In this case a manufacturing defect was causing numerous failures on a manufacturing line. The tops of these small bottles were coming off. The upper left photomicrograph is with the two halves of the bottle re-assembled. The upper right photomicrograph is of one of the glass fracture surfaces. The failures were occuring just below the transfer ring at a glass molding defect. The molding defect is a fold in the glass that acts as a stress concentrator. The lower left photograph is of an unused bottle with the defect. This is an unacceptable manufacturing defect and the parts werre returned as non-conforming.

Wine Bottle Failure Analysis

Glass failure analysis expert locates the origin of a failed wine bottle. Thye failure origin is at the top of the bottle on the inside rim. The origin is a crush spot on the inner rim. This was too high to be caused by a cork screw. It is believed that the damage occured before the bottle was purchased. Root cause of the failure is mechanical damage to the top of the bottle on the inner rim of the neck.

Glass Expert Analyses a Broken Bottle

Glass failure anlysis expert witness performs a root cause failure analysis on a broken bottle. This bottle broke into pieces (lowerleft figure). A failure analysis determined that the failure origin was in the bottle neck under the plastic cap (lower right figure). The glass expert removed the cap and the the residual polish (top left figure). The neck was cut open from the side opposite the visible crack, and the failure analysis revealed that the failure originated (arrow) at a damage site on the interior of the bottle neck (top right figure). Further study is required to determine the source of the damage.