The Dynamic Behaviour of Ultra-High-Molecular-Weight Polyethylene

Ultra-High-Molecular-Weight Polyethylene (UHMWPE) is used extensively in protection applications where the use of a light-weight material is particularly important. UHMWPE fibres are very strong due to the carbon chain of the polyethylene molecule is aligned along the fibre.

We are currently studying the impact resistance of UHMWPE dry woven fabrics and fabric-reinforced laminates. An examples is shown in Fig 1. The current challenge is to understand the behaviour of this type of material at different length-scales and loading rates. This is achieved through the material characterisation of single fabric yarn in a wide range of strain rates (see Fig 2.), the impact tests of fabrics and laminates using a gas-gun, and the numerical simulation of fabrics and laminates subjected to impact loadings.

Figure 1. Optical microscopy images showing: (a) the 4-harness satin weave pattern of the Dyneema® fabric and (b) the paths and cross-sections of the warp and weft yarns.

Figure 2. Footages showing the stretch and failure of single Dyneema® weft yarn subjected to tension at a strain rate of 3.3×10-5 s-1.