Baylor University.
Finite element-based failure analysis of composite laminates with non-destructive feature quantification.
Abstract
dc:description.abstractCarbon fiber reinforced polymers (CFRP) have become a mainstream material in the manufacturing process of industries from almost every sector - automotive, aerospace, energy, medical, sports and entertainment. While they are often preferred because of their superior material properties over traditional materials, their complex structural composition makes it very difficult to characterize and predict the failure process while they are in operation. This research experimentally investigates the failure mechanism of CFRP manufactured under three different loading modes: failure onset for a planar loading condition, delamination for a mixed mode static and dynamic bending/shear loading, and progressive failure of a part caused by improper drilling with complex initial damage; and generates predictive models through novel implementations of the finite element method that are experimentally validated. The first case uses the uncertainty in the ply orientation based on measurements from an ultrasound inspection to determine the probability of failure based on an extension of the classical laminate theory and the Tsai-Wu failure criteria. The probability of failure is determined by Monte Carlo Simulation and compared to the Mean Value First Order Second Moment method (MVFOSM), followed by a validation through a Monte Carlo simulation in the finite element environment. The probability of failure is quantified using a Cumulative Density Function (CDF) to decide whether a composite panel is safe for operation or needs replacement. The second case analyzes the delamination as a failure mode for L-shaped composite laminates. The influence of the stacking sequence in delamination growth is investigated to offer a better design solution for L-shaped composite panels subjected to bending stress. The delamination is characterized by micro computed tomography as a nondestructive mode of inspection for both static and dynamic loading conditions. The developed finite element model to predict the progressive failure response is validated through experimental data and fractographic images. Lastly, a three-dimensional static tensile testing case for a drilling induced damaged carbon fiber laminate is considered for progressive failure analysis. A novel method is developed to identify and quantify the inherent drilling induced damage in each ply interface using ultrasound. The damaged region for multiple samples is designed and simulated in the finite element environment to establish a correlation between the extent of the damage and the ultimate failure strain of the samples which is subsequently compared to experimental findings. This approach holds promise for the safety of manufactured structures by reducing uncertainty and enhancing accuracy in assessing load-bearing capabilities through the coupling of ultrasonically characterized damage zones with finite element simulations. This comprehensive failure analysis provides a valuable insight into the damage identification process, failure mechanism and practical implications for industry application.
Degree
thesis:*- Name thesis:degree_name
- Ph.D.
- Level thesis:degree_level
- Doctoral
- Grantor
- Baylor University.
- Year dc:date.issued
- 2025
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Rahul, Kirtunia, 1995-
- Advisor dc:contributor.advisor
-
- Jack, David Abram, 1977-
Subjects
dc:subject × 11Rights
dc:rights- Statement dc:rights
-
- Baylor University works are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact libraryquestions@baylor.edu for inquiries about permission.
- Language dc:language.iso
- en
Identifiers
dc:identifier.*- Handle dc:identifier.uri
- https://hdl.handle.net/2104/13823
- OAI identifier oai:identifier
- oai:baylor-ir.tdl.org:2104/13823