Masters Theses

Keywords and Phrases

Aircraft Structures; Compounding Method; Multiple Site Damage; NASGRO; Probabilist Fracture Mechanics; Widespread Fatigue Damage


“Multiple Site Damage (MSD) is the most common source of Widespread Fatigue Damage (WFD) affecting structural integrity of aging aircraft fleets. Therefore, an understanding of its progression, the development of methods to prevent the onset, and the maintenance procedures precluding WFD are important to improve aircraft fleet longevity. A reliable and efficient numerical methodology to perform detailed Multiple Site Damage assessment in riveted structural joints was developed. A probabilistic methodology was employed in conjunction with Monte Carlo simulation technique; the fatigue initiation life at every potential crack initiation site was determined and initial damage scenarios were generated. Probabilistic crack growth analyses were performed, thus accounting for multiple adjacent crack scenarios. Stress intensity factors for complex configurations were computed using compounding and superposition of classical and known solutions. The failure criterion employed was based on the first crack link-up where the plastic zone touch model was used. An automated tool to perform the MSD assessment was developed by using the Excel VBA code. The total time to crack initiation and total time to crack propagation obtained by numerical simulations agreed with the experimental results previously published. Statistical treatment was completed by using cumulative distribution function to establish maintenance action to preclude WFD. The results obtained from the MSD model were consistent with real aircraft maintenance intervals. The proposed methodology and the computer program developed were useful resources to predict MSD behavior and to establish maintenance actions to preclude its occurrence in real aircraft structures”--Abstract, page iii.


Dharani, Lokeswarappa R.

Committee Member(s)

Chapman, Brandon
Chandrashekhara, K.


Mechanical and Aerospace Engineering

Degree Name

M.S. in Aerospace Engineering


Missouri University of Science and Technology

Publication Date

Fall 2021


xv, 106 pages

Note about bibliography

Includes bibliographic references (pages 100-105).


© 2021 Haroldo Chacon, All rights reserved.

Document Type

Thesis - Open Access

File Type




Thesis Number

T 11939