Evaluation of the level of damage to thermoplastic flat sheets of acrylonitrile butadiene styrene (ABS) subjected to static tensile tests using static and unified damage and estimation of service life

Abstract

In this study, we are interested in the characterization of a flat plate in polymeric ABS under the uniaxial solicitation. We ran a series of tests on smooth rectangular specimens (defect-free) by ASTM 882-02 standards to characterize the material and provide a scale of comparison, as well as to investigate the combined defect effect on the mechanical behavior of ABS. Another panoply of tests was performed on rectangular test pieces with holes with a single notch and holes with a double notch. Then, we experimentally identify the propagation of their damage. The calculation of the damage, using models of experimental damage, led to determining the three stages of the evolution of the damage, which are the initiation, propagation, and complete deterioration of the material. Therefore, the approach of reliability (R) is a statical parameter, used to designate the critical life fraction concerning the notch depth (βc) of a modeled defect as a combined defect on an ABS specimen. In addition, the unified theory was developed in this context, on the one hand, to define the damage parameter, which is the internal variable that describes the state of damage of the structure in terms of the life fraction, and on the other hand for the theoretical re-evaluation of the level of damage. These techniques have the advantage of quickly assessing the performance and stability of the studied polymer and deciding whether to have an anticipatory maintenance strategy and an awareness of the safety requirements policy regarding the damage-reliability behavior of the studied specimens. From the latter, the discussion of the curves allowed us to maintain the limits of the ABS materials’ mechanical behavior and confirmed that the theoretical and experimental results show good agreement and correlation.