Blowing things up for science

Professor Steeve Chung Kim Yuen’s inaugural lecture, titled “Urban blast loading: An insight into scaling” was held on Tuesday, 10 October, in the Snape Building and attended by his peers, family, students, and former students.

The event featured three speakers, with Vice-Chancellor interim Emeritus Professor Daya Reddy opening the formalities, where he conveyed the rationale behind inaugural lectures.

“Inaugural lectures provide an opportunity to celebrate the achievements of the lecturer. They also, importantly, provide an opportunity for the inaugural lecturer to share his or her insights into their scholarly work in a manner that will be accessible to a broad audience,” Emeritus Professor Reddy said.

“So, the idea really is for the inaugural lecturer to tell us what they profess in a way that will be accessible to us – whatever our areas of study or interest or expertise. Professor Yuen’s lecture will focus on blast or explosions and their impact in an urban setting. Professor Yuen has been engaged in work in this area for around 30 years.”

An island, ballroom dancing, and an uncle

A proud UCT graduate from the Rodrigues Island in Mauritius, Professor Yuen’s academic journey started with the attainment of a Bachelor of Science in Engineering (Mechanical) in 1997. His unyielding pursuit of knowledge led him to a master’s degree in engineering, with a specialised focus on structural impact. His master’s work involved a meticulous study of the deformation and tearing of quadrangular stiffened plates under the influence of uniform blast loads. This academic milestone was followed by a PhD in Mechanical Engineering in 2006. He joined UCT’s Blast Impact and Survivability Unit (BISRU) as a research officer in 2008 and then the department of mechanical engineering as a senior lecturer in 2014. He was then promoted to associate professor in 2018 and to full professor in 2023.

“UCT’s Faculty of Engineering & the Built Environment has a lot to be grateful for, including the small Island Rodrigues [in Mauritius], Uncle Renaud, and ballroom dancing,” said Professor Alison Lewis, the dean of the Faculty of Engineering & the Built Environment (EBE).

“When he applied to university, he was accepted to Wits, and Natal, and UCT. It was one of his uncles, Renaud, that advised him to come to UCT. So, thank you, Uncle Renaud.”

Explosions, damages, and the controlled environments

Yuen’s inaugural lecture unpacked the understanding of how structures respond to blast loading, encompassing both air and buried charges. The primary objective is to develop protective structures against blast events and gain a deeper understanding of impact loading or crashworthiness.

The lecture was thoughtfully structured into two primary sections. The first part looked into the fundamental aspects of blast loading, while the second part showcased his recent work in the realm of scaling. The lecture was not merely a theoretical discourse but was supported by compelling experiments illustrated through a thoughtfully crafted slideshow.

In the fundamental part of the lecture, Yuen sought to elucidate how structures respond to blast loading by categorising explosions into three main types:

• natural (eg, volcanoes)
• accidental (eg, the gas tanker explosion in Boksburg in 2022)
• intentional detonation of explosives (eg, terrorist attacks).

“The sad part about explosions is that [they] cause damages, injuries, and loss of lives. Nobody wants to experience any of those. One of the major threats that we see worldwide is the intentional explosion; terrorist acts. The current war in Ukraine is typical of these [intentional explosion],” he said.

“My research focus is related to chemical explosion.”

“Explosion has normally got to do with harm, whereas blast loading is something that we do intentionally. My research focus is related to chemical explosion.”

The discussion extended to the unique challenges posed by urban blast loading scenarios, which are often created within controlled environments to simulate real-world conditions. He emphasised the multifaceted nature of blast loading, underscoring the need for precise instrumentation, the right sensors, and expensive equipment to obtain accurate results. Scaling, as explored by the professor, has enabled reasonable predictions in the field of urban blast loading. The shape of obstacles is emphasised as a key determinant of the impact outcome, requiring careful consideration in the design and protection of structures.

The lecture highlighted the crucial role of scaling in making accurate predictions, ensuring the safety of urban structures and, ultimately, in safeguarding lives.