About

Kara Peters is a Distinguished Professor in the Department of Mechanical and Aerospace Engineering at NC State University, where she also serves as the College of Engineering's Associate Dean for Graduate Programs. Her long-term goal is to contribute to the advancement of nondestructive evaluation and structural health monitoring techniques for composite aerospace structures, aiming to increase safety and improve performance of structural systems. She teaches courses such as Mechanics of Composite Structures and Aerospace Structures I and II, focusing on the current state-of-the-art in aerospace structures and future advancements. Dr. Peters works closely with her students to develop strong experimental problem-solving skills, guiding them in fabricating composite structures and integrating sensors into materials. Her research involves experimental investigations related to shear-horizontal waves, optical sensing, Lamb wave modes, and metamaterials, with a focus on nondestructive evaluation and structural health monitoring in aerospace applications.

Research topics

• Computer Science
• Engineering
• Physics
• Telecommunications
• Materials science
• Electronic engineering
• Acoustics
• Mechanical engineering
• Optoelectronics
• Electrical engineering
• Optics

Selected publications

• High-speed polarization imaging for <i>in situ</i> quality assessment in the fiber spinning process

  Applied Optics · 2025-06-10

  articleSenior authorCorresponding

  , high-speed polarization imaging method is developed and implemented for the detection of abnormalities in polymer fibers during production. The images are initially adjusted through a motion tracking algorithm. Depending on the production and image acquisition rates, the image analysis can then be processed through two methods, with the latter allowing for an increase in imaging frequency through data modeling. The imaging method is applied in both pre- and post-quenching conditions. The post-quenching results demonstrate the ability to detect defects once the polymer has reached a sufficient crystallization state.

  PublisherDOI

• Lamb wave amplification using flexurally resonant metamaterial

  Smart Materials and Structures · 2025-10-01 · 1 citations

  articleOpen accessSenior authorCorresponding

  Abstract In this paper, we design a unit cell and full metamaterial based on flexural resonance modes of a unit cell to focus antisymmetric Lamb waves in a thin plate. Numerical simulations of the metamaterial action on Lamb waves propagating through an aluminum plate are performed. The particular unit cell used is orthotropic to produce two distinct fundamental flexural resonance frequencies. The results demonstrate that the flexural resonance modes do hybridize with antisymmetric Lamb waves and can be used to manipulate the wavefront and focus Lamb waves for structural health monitoring applications. Additionally, this manipulation can be achieved at lower Lamb wave frequencies than the longitudinal resonance modes, for example below the first antisymmetric mode bandgap. The use of these modes produced a stronger focusing phenomena of the Lamb waves in an aluminum plate, as compared to previous metamaterial GRIN lens-based approaches. The orthotropic nature of the unit cell also produced two different dispersion curves based on the orientation of the unit cell with respect to the Lamb wave propagation direction. Experiments are then presented which validate the numerical simulations and predicted behavior from the dispersion curves.

  PublisherDOI

• Remote bonding of fiber Bragg grating sensors for Lamb wave measurements: a review

  Measurement Science and Technology · 2025-01-29 · 3 citations

  reviewOpen access1st authorCorresponding

  Abstract This article reviews the state-of-the-art in remote bonding of fiber Bragg grating sensors, primarily for Lamb wave measurements in structures. The presence of damage in a structure modifies Lamb waves through reflection and scattering, as well as the potential conversion between Lamb modes. While FBG sensors have been applied to capture ultrasonic waves for the past 30 years, the mounting configuration called remote bonding has recently come to attention as an alternative method to capture guided waves from structures. In this case, the FBG is not located at the bond, but instead at a remote location along the optical fiber. The Lamb waves are converted into propagating acoustic waves along the fiber, which are measured by the FBG. This article presents a discussion of the primary benefits of remote bonding, including the higher sensitivity to low-amplitude Lamb waves, the fact that the FBG can situated in a less harsh environment than the sensing region, and the insensitivity to quasi-static strain. The properties of ultrasonic modes in optical fibers and their conversion from Lamb waves is first reviewed. Strategies to detect these waves with FBGs and the associated instrumentation is also presented. Recent examples from the literature utilizing remote bonded FBGs are then presented. Finally, acoustic couplers to transfer the ultrasonic modes from one or more optical fibers to another are also reviewed.

  PublisherDOI

• Testing of Polymers and Composite Materials

  2025-01-01

  book-chapter1st authorCorresponding
  PublisherDOI

• Separation of Lamb waves modes using remotely bonded seven-core fiber Bragg grating Fabry-Pérot interferometer

  2025-05-22

  articleSenior author

  This paper presents the use of a seven-core optical fiber with FBGs written into each core for the unique identification of symmetric vs. antisymmetric Lamb waves traveling in a structure. The Lamb waves are converted into longitudinal and flexural modes that propagate along the optical fiber. An experimental demonstration of the technique is presented and the Lamb waves are also independently measured using a 3D micro-laser Doppler vibrometer for validation.

  PublisherDOI

• Low-dose intrapulmonary drug delivery device for studies on next-generation therapeutics in mice

  UNC Libraries · 2025-01-24

  articleOpen access
  PublisherDOI

• Focusing of Lamb waves through flexural resonance mode acoustic metamaterials

  2025-05-13

  articleSenior author

  This paper investigates the ability of a flexural resonance-based metamaterial to focus shear-horizontal waves in a thin-walled structure. Previous gradient-index lens based metamaterials have been applied to manipulate shear-horizontal waves, however the flexural resonance provides a stronger effect through the hyrbidization of the resonance with the mode. Through finite element simulations, this paper demonstrates this behavior for different regions of the resulting dispersion curve for the metamaterial unit cell.

  PublisherDOI

• High-sensitivity measurement of ultrasonic waves with FBG sensors

  2025-05-29

  article1st authorCorresponding

  Fiber Bragg grating (FBG) sensors have been widely applied for the collection of ultrasonic waves for structural health monitoring applications. One of the major challenges to using these systems for ultrasound detection is that the sensitivity of bonded FBG sensors to the low-amplitude waves is low. In this paper, we demonstrate strategies to increase the sensitivity of the FBG sensor to ultrasonic waves by converting the ultrasonic wave to a longitudinal acoustic mode in the optical fiber itself. The FBG then directly interacts with the longitudinal mode, to which its sensitivity is much higher. We address the coupling of the acoustic wave from the structure to the optical fiber and methods to tune this coupling for directional sensitivity.

  PublisherDOI

• Interaction of Lamb waves and sensors in structural health monitoring of carbon fiber composite

  2024-05-09 · 1 citations

  articleSenior author

  Carbon fiber composites have gained widespread popularity as advanced composite materials, finding their widespread applications across industries like aerospace, automobile, transportation, and health care. This popularity stems from their unique mechanical, electrical, and thermal properties. However, it is imperative to acknowledge that the structural integrity of these composites can undergo deterioration over time, mainly due to factors such as fatigue, impact damage, and aging. Hence, there is a burning need for a reliable method to monitor the health of these carbon fiber composite structures to prevent potential failure. The main goal of this research is to investigate the specific measurement issues when implementing a structural health monitoring approach for these composite plates by employing the guided Lamb wave technique. It is well known that the orientation of the fiber within a layered carbon fiber composite plate affects the propagation characteristics of Lamb waves. On the other hand, the sensors on and potentially embedded in the plates also interact with the Lamb wave in a dynamic manner. Using a micro-3D Laser doppler vibrometer, this research explores the microscopic interaction among the sensors, local fiber orientation and texture, and Lamb waves in these carbon fiber composite plates. Such insight can potentially lead us to a more viable means of interpreting the output of sensors and guided Lamb waves to detect defects within these composites.

  PublisherDOI

• Improved Damage Mapping with Hyperbola Approach for Guided Waves Based Structural Health Monitoring Using Fiber Bragg Grating sensors

  Journal of Physics Conference Series · 2024-02-01 · 1 citations

  articleOpen access

  Abstract Ultrasonic guided waves (GW) are commonly used in aerospace, civil, and mechanical industries for inspecting the health of a structure non-destructively. Traditionally the piezoelectric based actuators and sensors have been used for the actuation and sensing of GW. But the use of fiber Bragg grating sensors (FBG) is on the increase due to the unique opportunities offered by these sensors. There are several techniques that are used for damage mapping. The most commonly used in reflection based assessment domain are the ellipse based and hyperbola based approaches. Hyperbola approach is based on the time difference of arrival (TDOA). The time difference in the arrival time for two sensors with a common actuator is used for obtaining the hyperbola. The superposition of these hyperbolas for all possible actuator and sensor pairs may be used for damage localization. In this paper a new improved hyperbola approach for damage mapping is proposed by combining it with the ellipse based approach. In order to limit the number of computations a binary variable is introduced to check if the pixel fulfils the hyperbola and ellipse conditions. So only the regions of the structure which fulfil both conditions are mapped. This limits the number of hyperbolas which are identified as possible damage and improves the damage localization. The methodology is employed on a simple aluminium plate with acoustically FBG sensors. The performance of the new approach is compared with existing methods. The results indicate that indeed the improved hyperbola approach improves the localization. Also the computational load is reduced allowing more real time damage mapping.

  PublisherOA PDFDOI

Recent grants

• Collaborative Research: Full-Spectral Interrogation of Fiber Bragg Grating Sensors for Damage Identification

  NSF · $186k · 2009–2013

• SGER: Intelligent FRP Retrofits for Critical Structures

  NSF · $91k · 2005–2007

• Self-Healing Sandwich Composites

  NSF · $315k · 2008–2012

Frequent coauthors

• M.A. Zikry

  43 shared

• Stephen M. Schultz

  Brigham Young University

  35 shared

• Drew Hackney

  Southwest Research Institute

  31 shared

• Junghyun Wee

  North Carolina State University

  31 shared

• Mark Pankow

  North Carolina State University

  27 shared

• Sean Webb

  United States Air Force Research Laboratory

  23 shared

• Richard H. Selfridge

  KTH Royal Institute of Technology

  23 shared

• Mohanraj Prabhugoud

  Intel (United Kingdom)

  21 shared

Awards & honors

• Alumni Hall of Fame 2021
• Alumni Hall of Fame 2022
• Alumni Hall of Fame 2023
• Alumni Hall of Fame 2024
• Alumni Hall of Fame 2025