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 my colleague and I currently have funding for a PhD student (no restrictions on nationality).Development of advanced validation techniques for computational models

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