Modeling of mechanical property degradation by short-term aging at high temperatures

A study on the mechanical property degradation by short-term aging at high temperatures is performed. Samples are manufactured using a thermoplastic polymer (PEEK) and advanced polymer composite-2 (APC-2), and are aged at different temperatures for different times. The flexural properties of the aged samples are measured by 4-point bending tests. An appropriate mathematical equation is proposed to model the degradation data as a function of time and temperature. Numerical techniques are employed to find the optimal values of the parameters using transient temperature profiles. The evaluated results are discussed in comparison with results from previous works to prove the validity of the model. Physical interpretations of the results are provided to support assumptions involved in the model. To illustrate the effectiveness of the model, it was applied to a simulated manufacturing process and a mathematically defined service condition. The model could successfully predict the property loss during manufacturing and service, which could be utilized as a reference in determining the durability and the lifetime of the product. (C) 2002 Elsevier Science Ltd. All rights reserved.