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COMPONENT FAILURE MUSEUM

The main sections of the museum are listed below;

Metal Fatigue
Manufacturing Faults
Bicycle Components
Corrosion
Polymers
Composite Materials

Tools of the trade, some ways to investigate problems;
Photoelasticity
Dye penetrant testing

Glossary
of materials engineering terms

 

Polymer Failure - Scissors

Click on pictures below for full size image in new window.

 

 Broken scissor handle

Many goods are discarded because of the failure of one component. These household scissors were highly serviceable after 7 years except for a fracture to the injection moulded handle. In use it distorted and trapped the users skin .

 

The fracture area is shown in the lower left of this image. Localised pre-cracks (also called crazes) were visible elsewhere on the handle, and as shown below, on the diametrically opposite location in particular.

 

The diametrically opposite link has a craze, these crazes could have been started at the same time as the main crack, or may have resulted from excessive bending due to use in the broken condition.

The fracture surface of the handle.

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ed:AG 17/12/01

 
 
© 2005 Materials Engineering - Page last modified 18-Dec-2007