Abstract
Although the understanding of volume change is of crucial importance to analyze and model the mechanical behavior of polymeric materials, it is highly understudied in the open literature. This article deals with the assessment of the volume change in polyetheretherketone when submitted to compressive loads. The volume change is measured by the end of mechanical tests before and after unloading. Therefore, the total (before unloading) and residual (after loading) volume changes are measured for strain rates ranging from 10(-4) to 3000 s(-1) and temperatures ranging from +133 to +433 K, that is, -140 degrees C to +160 degrees C. It is demonstrated that the total volume is almost constant in terms of the axial strain independent of strain rate and temperature. The residual volume slightly increases with increasing axial strain. This conclusion is obtained either by direct measurements or by a simplified model developed in this article. However, the volume change is softly affected by the specimen geometry.