John M. Papazian

TL;DR: In this article, the initial stages of fatigue crack formation in the commercial aluminum alloy 7075-T651 were studied under moderately high fatigue loads in a scanning electron microscope, and the experimental conditions were designed to mimic the behavior of fastener holes in the lower wing covers of military attack aircraft, thus the loading parameters were such that local plasticity was expected.

TL;DR: In this paper, three sensor systems were evaluated for their ability to detect early stage fatigue cracking in open holes, including a Meandering Winding Magnetometer Array (MWM), a through-transmission ultrasonic technique and an Electrochemical Fatigue Sensor (EFS).

TL;DR: In this paper, a science-based structural integrity prognosis system (SIPS) is developed to provide prompt, informed predictions of the structural viability of individual aircraft based on tracking of their actual use and modeling of anticipated usage.

TL;DR: In this paper, an elastomeric interpolating layer is placed on top of the hemispherical forming ends of the die elements to prevent dimpling of the composite lay-up.

TL;DR: In this article, a tooling apparatus consisting of opposing first and second dies adapted to receive a three-dimensional honeycomb core article therebetween and including opposedly aligned arrays of elongated mutually parallel translating pins, each terminating at a tip end and arranged in a matrix for longitudinal movement between a retracted position and an extended position engageable with the article.