Photo of Dr William Christian

Dr William Christian

Senior Lecturer Mechanical and Aerospace Engineering

Research

Research Overview

If you are interested in my research then I currently have two fully funded (i.e. tuition and maintenance costs) PhD studentships:
Nuclear engineering related, Linking historic, contemporary, and future inspection data for improved asset monitoring
Wind generation related, Improved structural integrity assessments for wrinkling defects in composite turbines

Defect Mechanics in Composite Materials

The surface strain field on a composite coupon containing fibre-waviness under a four-point bend load. The strains were measured using stereoscopic digital image correlation.
The surface strain field on a composite coupon containing fibre-waviness under a four-point bend load. The strains were measured using stereoscopic digital image correlation.

I use digital image correlation and thermoelastic stress analysis to experimentally determine how defects cause structures to deform and fail. Much of my work has been focused on carbon-fibre reinforced polymers, looking at impact damage and fibre-waviness. Recently I have worked on more exotic ceramic matrix composite materials.

Non-destructive Evaluation of Structural Materials

Pulse-echo ultrasound C-scan used to view fibre tows in a composite coupon.
Pulse-echo ultrasound C-scan used to view fibre tows in a composite coupon.

I use ultrasound and a novel strain-based defect assessment that I have developed to predict material properties for defective structures. I use simple statistical algorithms to make these predictions.

Computer Vision for Engineering Data

A displacement field on the surface of an indented block measured using digital image correlation (top) and a reconstruction of the same displacement field using fifty image moments (bottom).
A displacement field on the surface of an indented block measured using digital image correlation (top) and a reconstruction of the same displacement field using fifty image moments (bottom).

I use orthogonal decomposition of image data to perform pattern recognition. I also use texture analysis techniques for characterising defects.

Research Grants

MUSICA: Modelling UltraSonic Inspection of Challenging defects for Automated analysis

RCNDE

March 2023 - June 2025

Smarter Testing

INNOVATE UK (UK)

January 2021 - December 2024

SteADfASt – Strain-based Assessment of Defects for Aerospace Structures

ENGINEERING & PHYSICAL SCIENCES RESEARCH COUNCIL

January 2022 - December 2022