# 1992 Eindhoven
The case for development of rational design criteria for thinwalled polyethylene pipe linings is argued. Progress to date on a programme of research formulated to meet this objective is discussed. Short and long term behaviour under stress is modelled using elasto-plastic and elasto-viscoplastic constitutive models based on extensive material testing. Finite element simulation of representative systems tested to failure in the laboratory, and the long term behaviour of field systems are described.