Engenuity Crush Test Fixtures

Engenuity have been measuring the crush performance of composites for more than a decade and have developed our own dedicated fixtures for this purpose. In consultation with organisations such as the UK’s National Physical Laboratory, the University of Utah and the CMH-17 (Composite Materials Handbook) crashworthiness working group, we have developed and are now using our third generation of crush fixtures which have been designed for high throughput, consistency of results and ease of use. Our crush fixtures are portable and can be installed in servo-hydraulic apparatus or drop towers either freefall or spring assisted such as the Instron Dynatup.

The Mk3 crush fixture takes coupons water-jet cut from flat sheets of material. The fixture can be used both for initial crush screenings, to check if a new material is suitable for use in crush members, or for full material crush characterisation to determine the crush properties for input to FE analysis. Alternative target plates are used to vary gap-height. For a detailed explanation on determining the correct gap-height see our pages on gap-height-assessment. In addition to the measurement of crush the fixture is also used to measure compression from an un-tabbed low cost specimen ideally cut from the same source material in order to understand the materials Crush Compression Ratio (CCR).

Crush performance of composite materials can be affected by geometry, notably curved regions, for example the corner regions of a rectangular section give higher crush stresses than flat regions due to suppression of delamination in these regions. With our pin-stabilised target plate we can measure these elevated performance levels from flat coupons. For a detailed discussion of this aspect see our pages on geometry effects and types of crush.

We have made our Mk3 crush fixture available for purchase – please contact to discuss detailed specifications.