A stacked cylinder approach for standardized high-throughput uniaxial fatigue characterization

Abstract

Despite the critical importance of mechanical reliability in our modern economy, the prediction of fatigue failures remains a challenging endeavor. Traditional fatigue testing methods are not only slow and costly but also plagued by high variability, making it difficult to calibrate predictive models for real-world utilization. Towards addressing this challenge, we present a uniaxial mechanical fatigue testing concept that aims to increase testing throughput by more than an order of magnitude, while maintaining testing cost and consistency with popular standards, ASTM E466 and ISO 1099. After considering various concepts to enhance uniaxial fatigue testing throughput, we present a mechanical analysis of the most promising concept. A prototyped design was developed and demonstrated with 39 aluminum 6061-T6511 test specimens subjected to 2 million loading cycles. The performance of the prototype was assessed against the popular standards via numerous strain gauge measurements over the duration of the test and by comparing the failure distribution to a traditional MMPDS fatigue dataset. Ultimately, the prototyped high throughput design produced fatigue life data that was in general agreement with the traditional MMPDS dataset. To close, the authors present potential extensions and applications to the method.