Methodology of Accelerated Characterization for long-term creep prediction of polymer structures to ensure their service life

Abstract

Abstract Predicting long-term creep behaviour (10 or 20 years) is important in the development and design of thermoplastic structures to ensure their service life. But providing robust material data to engineers is not easy, as testing is expensive and time-consuming. The purpose of this paper is to propose a new Methodology of Accelerated Characterization for long-term creep Prediction (MACcreeP) which gives more material information much faster and at a lower cost, than Classical Methodology (CM) used today by engineers. In order to prove the effectiveness of this new method, the material used for the study is a well-known high density polyethylene grade (HDPE). More precisely MACcreeP is a characterization protocol based on creep tests performed in true tensile stress conditions over short time periods (24 h) and at different temperatures combined with the Time-Temperature Superposition Principle to construct master curves. In addition to the material data obtained over a short period of time, the data generated by the behaviour laws and the use of the CREEP law in a FEA software allows a more predictive numerical response than in CM. Finally, this methodology, which implies very few tests, allows to compare and choose the appropriate material properties to design a thermoplastic structure which will comply with end-use product requirements.