Posts Tagged: Oh-Sung Kwon

Disaster-proof: Major CivMin lab upgrade lets engineers design structures that can better withstand earthquakes, hurricanes and tsunamis

Funding from the Canada Foundation for Innovation will be used to acquire an adjustable,
multi-dimensional loading module and other equipment for the Structural Testing Facility

 

A new adjustable multi-dimensional (AMD) loading system will soon be added to U of T Engineering’s Structural Testing Facility. (Image: Myron Zhong)

An upgraded facility at U of T Engineering — one that is unique in the world — will let engineers test next-generation infrastructure designed to be resilient in the face of natural disasters, from hurricanes to earthquakes.

A grant announced today from CFI’s Innovation Fund 2020 will fund a suite of new tools and equipment to be housed within U of T Engineering’s existing Structural Testing Facility. They will be used to design everything from elevated highways to high-rise residential buildings to nuclear power plants, including replacements for legacy structures across North America.

“Much of our infrastructure is decades old and needs to be replaced,” says Professor Constantin Christopoulos (CivMin), the project leader and Canada Research Chair in Seismic Resilience of Infrastructure.

“The scientific and engineering communities, along with governments and the private sector, are becoming increasingly aware of the inherent vulnerability of our infrastructure. We also need to design new structures to address new pressures, such as a rapidly growing Canadian population, and more frequent extreme weather scenarios due to a changing climate.”

The centrepiece of this new development is the world’s first fully movable, adjustable multidirectional, large-scale and large-capacity loading frame.

“This unique piece of equipment will allow structural elements and structural systems to be tested under more realistic loading conditions,” says Christopoulos. “We’ll be able to better simulate the complex effects of extreme loading events, such as earthquakes, tornadoes, hurricanes or tsunamis.”

The adjustable, multi-dimensional loading module will be capable of applying up to a total of 2,000 tonnes of force in six translational and rotational directions for specimens of up to eight metres tall and thirty metres long.

The project will also include new state-of-the-art sensing equipment and the redesign of 500 square metres of lab space. Construction is expected to begin in 2022.

To make full use of it, Christopoulos will be working with a large team of experts from within and beyond U of T Engineering. Project partners include U of T Engineering professors Oh-Sung KwonEvan BentzOya Mercan and Jeffrey Packer (all CivMin). This team is also collaborating with a team of structural engineering and large-scale testing experts at other leading North American facilities to develop, commission and use this unique equipment. Collaborating institutions include:

  • Western University’s WindEEE and Boundary Layer Wind Tunnels
  • University of British Columbia
  • University of Sherbrooke
  • Polytechnique Montreal
  • University of Illinois

Once completed, the new facility will be used for research by 10 professors from U of T and their national and international collaborators. It is also expected that it will allow for dozens of unique graduate student research projects and industry tests every year once it is fully operational.

Together this team will be able to carry out a technique known as “distributed hybrid simulations.” This means that full-scale portions of real structures — such as concrete pillars or steel beams — will be tested simultaneously in each of these labs across North America.

By integrating all of these physical tests into a single numerical model, they can use the experimental feedback of each of the large-scale elements to more realistically simulate the response of the entire infrastructure system to extreme loading conditions. The data from the physical experiments will be integrated in real-time with models run using high-performance computers and the UT-SIM integration platform.

“This facility will enhance our capabilities not only here at U of T, and across Canada, but will position Canadian engineers as global leaders in the area of structural resilience” says Christopoulos. “It is a critical step toward designing the resilient cities of the future.”

By Tyler Irving

This article originally published on Engineering News


Half a world away, but heading home for the holidays

Prof. Oh-Sung Kwon displays his certificate for completing the Seoul Trail in Seoul, South Korea October 2020. (Photo courtesy Prof. Oh-Sung Kwon)

Prof. Oh-Sung Kwon is coming home to Toronto this week, on Saturday, December 19, after a six-month research leave. “It has been a long six months,” shares Kwon. “I look forward to seeing my family in December and meeting my students in person after the COVID-19 pandemic.”

The research leave was planned long before the current health crisis was known – it just added a few more twists. Like any other CivMin professors, he has been keeping in touch with the structural research students he supervises via video meetings. Teams chats are the new norm for just about everyone during the pandemic since in-person contact is strictly limited to lab work at U of T. The difference, however, is he’s nearly half a world away in Seoul, South Korea.

“Even though I spent six months in Korea, there has not been much difference in having meetings with my students. The only difference is the meeting time; it is either early in the morning or late in the evening due to the 14 hours of time difference.”

Since departing Toronto on June 19 for Seoul, Kwon has maintained regular contact with research students at both U of T and Seoul National University (SNU). He has spent his research leave in Korea to progress a few collaborative research projects there.

“Back in 2016, I hosted an international workshop at the University of Toronto, inviting researchers and professors from several research institutions in South Korea to promote international collaborations. Since then, we have developed a few research projects. Including myself, five professors in the Structures section have collaborated with or closely interacted with Korean researchers. In the past four years, three PhD students visited my group from Seoul National University. My graduate students spent 26 person-months at the Korea Institute of Civil Engineering and Building Technology (KICT) and Korea Atomic Energy Research Institue (KAERI). I recruited one PDF from SNU, with another one joining in January 2021.”

One of Kwon’s primary research focuses is on developing realistic simulation methods for structures subjected to extreme loads such as earthquake, wind, and fire. Through the research collaborations of the institutions, his group can access unique testing facilities, such as a wind tunnel and fire testing facilities, not available at U of T.

He says, “During my stay, I have been co-supervising one graduate student and one PDF at SNU to implement the real-time aeroelastic hybrid simulation (RTAHS) method for bridge deck models in their wind tunnel facility. I co-supervised one Ph.D. student in the past four years on the development of deep neural network (DNN) models for nonlinear response predictions. The student will complete his doctoral degree soon. Also, during my stay in Korea, I have been developing a new project with KICT to run more conventional fire endurance tests and hybrid fire tests at their fire testing facility in 2021.”

Prof. Oh-Sung Kwon (L) with the student and the PDF who are working on RTAHS of a bridge deck section model. Real-time aeroelastic hybrid simulation testing setup for a bridge deck section model at SNU. It is replicated from the design that Prof. Kwon’s group developed at U of T (Photo courtesy Prof. Oh-Sung Kwon)

Prof. Oh-Sung Kwon takes in the view on the Seoul Trail. (Photo courtesy Oh-Sung Kwon)

For personal recreation, as well as beneficial exercise, he has stayed active with regular hikes around Seoul on the well-known Seoul Trail. The 157 km trail winds up and down hilly terrain, providing a varied and sometimes challenging Saturday trek. Kwon began his ambitious sojourns in July and completed the final section October 31. Recognition, in the form of a certificate, allowed him to realize a lifelong goal.

A map of the Seoul Trail’s circuitous route around the city with Prof. Oh-Sung Kwon’s hike segments.

A planned break to see his family simply was not to be, as quarantine measures in both countries were found to be too restrictive. “Originally I was planning to go back to Toronto for two weeks in late September to spend Thanksgiving with my family. But I realized the two weeks of isolation upon return to South Korea were very strict. And, also, two weeks of quarantine in Toronto is also restrictive. In total I would need to spend one month in isolation if I travelled back and forth, so I decided to stay here and just leave at the end of my recess.”

Throughout the summer, and early fall, South Korea held COVID-19 at bay with extremely low case counts. Kwon recounts the open access to facilities, such as libraries, while everyone kept to wearing masks as a matter of course. “I think Korea flattened and reduced to the curve very quickly. I think a great example of taking control and I think there’s also in the country more of a personal feeling of responsibility, or obligation.”

The number of cases in all of South Korea, with a population of 52 million, is currently starkly better than even the lone province of Ontario (pop. 16 million) or the City of Toronto’s three million. “We see the third wave of COVID-19 situation in Korea with 451 new cases for today [November 30]. There are further restrictions imposed to a few businesses (bars, cafes, gyms, restaurants, etc.), but not as strict as in Toronto. For example, all restaurants are still open until 9 p.m.,” he says.

The relatively better situation is met with caution,”With greater population density, it can spread a lot quicker here, so we all have to be more careful.”

Kwon returns home to his wife and three children in Toronto, though he has enjoyed his time visiting extended family while back in South Korea, “I have a big family in Seoul. If we get together with my three sisters and their family, we have about 18-19 family members.”

During his time away from home there have been several notable academic recognitions:

Kwon reflects on his six-month research leave as an excellent opportunity for him to wrap up a few projects and develop a few more for the next few years.

By Phill Snel


Trio of PhD candidates win international honours in video thesis competition

Video thesis competition winners CivE PhD candidates (L to R) Moniruzzaman Moni, Pedram Mortazavi and Xuguang Wang.

Three PhD candidates from the Department of Civil & Mineral Engineering (CivMin) at the University of Toronto have won honours for their video thesis entries in an international competition.

Moniruzzaman Moni, Pedram Mortazavi and Xuguang Wang, all civil engineering PhD candidates, won three out of the 10 honours awarded for the “3-minute Thesis” video competition held by Multihazard Engineering Collaboratory on Hybrid Simulation (MECHS). MECHS, funded by the National Science Foundation in the U.S., made the announcement with a full list of categories and winning videos online.

All three U of T winners have Professor Oh-Sung Kwon as a supervisor, with Mortazavi having co-supervisors Professors Constantin Christopoulos and Kwon.

CivMin Professor Oh-Sung Kwon

CivMin Professor Constantin Christopoulos

One of the main research interests of Professor Kwon’s research group is on the development and application of hybrid simulation methods where diverse experimental specimens and numerical models are integrated to accurately simulate responses of structures subjected to extreme loads. As part of the research program, the research group has developed the UT-SIM (Simulations for Structural Resilience​) framework through which various numerical and/or experimental tools can be seamlessly integrated.

In the early development, the main focus of the framework was to simulate structures subjected to earthquake excitation. In the past five years Prof. Kwon’s research group has expanded the framework such that structures subjected to fire or wind loads can be simulated. Some of the work is performed within the Department’s large indoor Structures Lab, which enables full-scale testing of building components.


CivE PhD candidate Moniruzzaman Moni‘s entry, titled “Real-time aeroelastic hybrid simulation of a base pivoting model building in a wind tunnel,” was selected from a large pool of entries as a winner in the “Creativity” category.


CivE PhD candidate Pedram Mortazavi‘s entry, titled “Four-Element Hybrid Simulations on a Steel Structure with Cast Steel Yielding Connectors,” was selected as a winner in the “Novelty” category. Mortazavi’s work is in collaboration with Cast Connex.

Mortazavi has been honoured with awards before, and was just last fall awarded the G. J. Jackson Fellowship Award from the Canadian Institute of Steel Construction at the Canadian Steel Conference and awarded the Donald Jamieson Fellowship from the Canadian Society of Civil Engineering at the CSCE annual conference,

 


CivE PhD candidate Xuguang Wang‘s entry, titled “Development and Applications of Hybrid Simulation Method for Fire Testing, was selected as a winner in the “Technical” category.


While having three out of 10 winners of the competition from Professor Kwon’s group is impressive, he also had a hand a fourth winner’s work. A winner from Seoul National University in Korea is co-supervised by Prof. Kwon for his work on aeroelastic hybrid simulation of a bridge deck.

 

By Phill Snel


PhD candidate receives award at Canadian Steel Conference

Designed to fail: an elegant solution to save buildings during earthquakes

Civ PhD Candidate Pedram Mortazavi, MASc, P.Eng, poses with a cast steel link in the Structures Lab at the University of Toronto’s Department of Civil & Mineral Engineering in Toronto. His thesis is titled: Cast Steel Replaceable Link Elements in Steel Eccentric Braced Frame (EBF), and is designed to allow a specific piece of a building structure fail in an earthquake so as to allow the structure to remain intact. The sacrificial piece is designed to be standardized and replaceable afterwards.
PHOTO: Phill Snel, Department of Civil & Mineral Engineering/ U of T

Pedram Mortazavi, a CivE PhD candidate in structural engineering under the supervision of Professors Constantin Christopoulos and Oh-Sung Kwon, is championing work to mitigate earthquake damage to buildings with a focus on at-risk areas of the world. In recognition of his work in this area, Mortazavi will receive the G.J. Jackson Fellowship Award from the Canadian Institute of Steel Construction on Tuesday, October  1 at a ceremony in Montreal.

Earthquakes occur suddenly, and usually without warning. When they occur near populated areas, it typically leaves a trail of devastation in its wake, including lost lives and unsafe buildings. Every event results in renewed concerns about widespread damage to buildings and infrastructure in earthquake-prone zones, leading researchers to develop solutions that will help the structures in these communities be more resilient to the shocks of an earthquake.

Mortazavi’s thesis, Experimental Validation and Performance Assessment of Cast-Steel Replaceable Links in Steel Eccentrically Braced Frames (EBFs), sounds complex, but is elegant in its simplicity. In essence, the solution to save buildings from catastrophic failure is to assign pre-determined pieces of the building’s structure that are designed to be sacrificed. Using steel castings for seismic applications, an area that has been pioneered for the past 15 years at the University of Toronto, allows for the sacrificial piece to encompass the optimal stiffness, strength and ductility properties to adequately protect the structure from the severe loading effects of earthquakes.

It might seem counter-intuitive to design for failure, but by designing a specific portion of a structure to absorb all the deformations of an earthquake, it allows for the building to remain structurally viable. And, according to the plan, the designated piece(s) can be replaced after they are damaged by an earthquake.

Mortazavi neatly sums up the project: “What we’re doing in the project is to develop an off-the-shelf product by using all the advantages offered by steel castings that will not only improve the performance of the structure in the event of an earthquake, or any extreme events, but would also ease the construction process significantly. Imagine instead of doing a detailed design and having to make a custom element, you can simply order it from a catalogue.”

ILLUSTRATION: Cast steel links as energy dissipative elements in mid-rise steel eccentrically braced frames

ILLUSTRATION: Cast steel links as energy dissipative elements in mid-rise steel eccentrically braced frames

“The portion of the beam that is between the braces acts as a fuse. So when an earthquake happens, you have very large forces generated in the building and transferred to the ground through the building. If that happens properly, the building won’t collapse or deform too much past the point of being repairable. If, however, the structure deforms too much, it could sustain significant structural damage, and at this point, it may be easier to completely demolish the building,” he said.

Alumni Carlos de Oliveira (CivE MASc 2006) and Michael Gray (CivE 0T5, PhD 2012) figure prominently in the project too. “Based on their research as students, they founded Cast Connex, an industry-leading company in the area of cast steel. I’m working very closely with Dr. Gray, which is interesting, because he’s also a former recipient of the G.J. Jackson Fellowship (CISC) and the Donald Jameson Fellowship (CSCE), both awards I received this year,” said Mortazavi. Mortazavi is also working closely on his project with Justin Binder (CivE MASc 2015) who leads the new products development team at Cast Connex.

Asked if the product might soon be implementable, he says, “Within five years, or so, would be my guess. We should be able to wrap up the research program within two years. But structural engineering is a discipline where taking an idea from innovation to implementation can be a lengthy process so I’m rounding up.”

For now, though, the full-scale testing of the cast steel links continues at U of T. “When it comes to testing new ideas and new systems in the lab we have to test them realistically and with the most accurate methods. That’s where Professor Kwon’s unique expertise is incredibly valuable.”

Kwon echoes their mutual respect, “Pedram is one of the best students whom I supervised so far. He is very organized and has very solid technical background. In addition, he can work well with other students, industry partners, and technical staff which make his project run smooth. I am confident that he will be an excellent researcher and/or engineer with his strong technical and people skills.”

In California, after a major earthquake in 1971 it was mandated that more than 8,000 unreinforced masonry buildings with highest risk of collapse be retrofitted. In Canada, previously-built structures are “grandfathered”, and are not always required to follow the building code. Mortazavi believes that if Canada were to adopt a system similar to that in California, “it would definitely ensure that we have a more resilient community in the event of an earthquake.”

“My research advisor, Professor Christopoulos, also says ‘Ultimately what we’d like to do is have a city where an earthquake happens, and no one is worried about it,’ You can just sit tight, for a few seconds or a minute while the earthquake comes and goes, and then the building could be quickly re-occupied without any major disruption.”

Christopoulos further emphasized Mortazavi’s capacity for producing high impact work with his project: “ Pedram’s strong academic background, real industry experience and his close collaboration with leading innovators like Gray, Binder and deOliveira makes it a real possibility that what he is now developing may one day be protecting hundreds of buildings in North America and beyond. The experience he is gaining in this challenging process, from R and D all the way to tech transfer in this project, will give him a strong basis to continue innovating and impacting our field after graduation.”

 

Julie Audet, Vice-Dean of Graduate Studies at U of T, had kind words in reflection of Mortazavi’s TA Teaching Excellence Award in 2018, a first for the Department of Civil & Mineral Engineering, “Pedram is not only a world-leading researcher in earthquake engineering, he is also an award-winning educator. I first met Pedram when I was trying to get in contact with award-winning teachers at U of T to help with training new teaching assistants in FASE. I found the recipient list for the 2018 teaching excellence award where Pedram was listed. I contacted him and he immediately accepted to organize a training session. Pedram is extremely gifted and always eager to give back to our faculty.”

 

So why study structural engineering?

A 2003 earthquake affecting Bam, Iran registered a magnitude of 6.6 on the Richter scale and created an indelible memory for Mortazavi, then a boy living in Tehran where his father was a structural engineer. The earthquake killed over 26,000 and injured some 30,000. He recalled thinking about the buildings, primarily mud structures that collapsed completely, “We’ve been to the moon, so why can’t we keep these buildings standing during an earthquake? What’s the problem? That was definitely a factor pushing me in the direction of my studies.”

As for why he chose Canada, the reply is immediate, “I came to Canada, because of its reputation for excellence in education and because it is one of the most welcoming nations. Probably the most.”

Mortazavi, at U of T for his PhD since 2016, is humble about the work he’s doing in the full-scale Structural Testing Facilities and gives credit to his predecessors. “It’s not just mine. Our colleagues at Cast Connex have also worked on it and research was also initiated by Professor Christopoulos and his former student. We’re just passing off the torch.”

 

By Phill Snel

==

 

FAQ:

Q: How much do the steel links weigh?
A: The smallest is around 120 kg (260lbs) and the biggest is about 275 kg (605lbs) Q: At what level do they fail? Or not snap, but simply become deformed?
A: They can sustain significantly more deformation, compared to the conventional ones. Our prediction is probably 1.5 – 2 times greater. The conventional ones fail at 0.08-0.12 radians rotations. We are expecting these to perform well up to rotations of 0.16 radians.

 

 Awards & notes:

  • Ontario Graduate Scholarship (2016)
  • NSERC PGSD (2017-2020)
  • John L. Kellerman Fellowship (2017) – Canadian Institute of Steel Construction (CISC)
  • TATP TA Teaching Excellence Award (2018) – Centre for Teaching Support and Innovation (CTSI) at the University of Toronto
  • J. Jackson Fellowship (2019) – Canadian Institute of Steel Construction Education and Research Council (CISC-ERC) CISC – 2019 G. J. Jackson Fellowship Award post
  • Donald Jamieson Fellowship (2019) – Canadian Society for Civil Engineering (CSCE)
  • Former President of the University of Toronto EERI (Earthquake Engineering Research Institute) Chapter (2017-2019)
  • He will be teaching a third-year Steel and Timber Design course (CIV312) at U of T this fall.

 


Pedram Mortazavi wins 2018 TA Teaching Excellence Award

CivE PhD Candidate Pedram Mortazavi was one of just five recipients from more than 550 nominated teaching assistants from across the University of Toronto. (Photo: Keenan Dixon)

CivMin PhD Candidate Pedram Mortazavi was one of just five recipients from more than 550 nominated teaching assistants from across the University of Toronto. (Photo: Keenan Dixon)

Pedram Mortazavi (CivMin PhD candidate) has won a 2018 TA Teaching Excellence Award from the University of Toronto’s Teaching Assistant Training Program (TATP).

Mortazavi, a PhD candidate in the Department of Civil & Mineral Engineering, is one of just five recipients from more than 550 nominated teaching assistants (TAs) across the entire University. He has taught Steel and Timber Design and, Principals of Earthquake Engineering and Seismic Design.

“It may sound cliché, but I love teaching,” said Mortazavi. “TAs are a significant part of the student learning experience. I believe that the effect that instructors and TAs have on students goes far beyond the classroom. Beyond teaching the material, TAs play an important part as role models.”

Mortazavi was nominated by several students of Steel and Timber Design, of which he was the Head TA. Even after his courses were over, he found himself answering student requests for career and other advice.

“He learned all of our names and truly made himself available to students whenever they had a question,” said Chris Rotella (CivE Year 3), one of the students to nominate Mortazavi. “He was very invested in the success of the students and even when an email came in at 9 p.m., he was happy to answer and help us.”

Pedram Mortazavi with two of the students who nominated him for the TA Teaching Excellence Award, Andrew Lau (CivE Year 3) and Chris Rotella (CivE Year 3).  (Photo: Keenan Dixon)

Pedram Mortazavi with two of the students who nominated him for the TA Teaching Excellence Award, Andrew Lau (CivE Year 3) and Chris Rotella (CivE Year 3). (Photo: Keenan Dixon)

“He checked in to make sure we all had the information we needed in order to complete our projects,” continued Andrew Lau (CivE Year 3), another nominator. “When we couldn’t figure out part of our model, rather than just provide the solution, he went back to the foundations of CIV100 to explain how to fix the problem.”

Mortazavi credits this recognition and his success in teaching the course to its professor, Constantin Christopoulos (CivMin).

“Professor Christopoulos allowed me to contribute in a significant and meaningful way,” explains Mortazavi. “I was able to plan and run the tutorials, lecturing the class from time to time and also defining the scope for the term project. It was because of these things that I felt that much more invested in the students and the course.”

“He was constantly thinking of progressive methods and clear ways to teach the course material,” said Christopoulos. “He devised a teaching apparatus that replicates the physical behaviour of structural engineering components, which is often difficult to visualize.”

Mortazavi valued and implemented the feedback that he received from both Christopoulos and students.

“He proactively asked for advice and feedback about useful and effective teaching methods,” said Christopoulos. “As a result, Pedram has developed excellent skills for encouraging students to participate in classes and tutorials.”

Mortazavi is co-supervised by Professors Christopoulos and Oh-Sung Kwon (CivMin). His research — focused on the performance and experimental validation of cast steel link elements in eccentric braced frames — explores the idea that during an earthquake there is an element of a building that is engineered to absorb seismic energy and ensure that the remainder of the structure is undamaged, thus ensuring the safety of building occupants and first responders.

Mortazavi’s research sees him working with U of T startup CastConnex and, alumni Michael Gray (CivE PhD 1T1) and Carlos de Oliveira (CivE MASc 0T6). He is also the President of the Earthquake Engineering Research Institute Chapter at the University of Toronto.

Mortazavi is the first Civil Engineering student to received the TATP Teaching Excellence Award since it was created in 2003. The award seeks to value the work of TAs who regularly inspire and challenge undergraduate students. The awards committee considers the TA’s knowledge of his or her subject area, communication skills, organizational skills, demonstrated enthusiasm, and ability to provide students with effective feedback, as well as testimonials from both students and faculty supervisors.


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