Floating offshore wind energy is quickly becoming a viable
source of affordable, renewable energy in the U.S., however, offshore wind
turbines are susceptible to damage from high winds and waves.
Researchers at Oregon State University, received $1.25 million from the U.S. Department of Energy to simulate the combined and complex effects of wind and wave forces on turbines by conducting physical experiments and numerical models. Barbara Simpson, assistant professor of structural engineering, is the principal investigator. Her colleagues on the project include Bryony DuPont, associate professor of mechanical engineering and the Boeing Professor of Mechanical Engineering Design, Bryson Robertson, associate professor of coastal and ocean engineering and co-director of the Pacific Marine Energy Center, Pedro Lomónaco, director of the O.H. Hinsdale Wave Research Laboratory, and Ted Brekken, professor of electrical and computer engineering
“There is a considerable need to develop open-source,
flexible, modular frameworks that expand the capacities of physical testing
facilities to accelerate the development of the U.S. floating offshore wind
industry.” said Simpson. “In this simulation, the physical and numerical
portions interact through sensors and actuators to represent the response of a
floating-offshore wind turbine to combined wind and wave loading, where the
wave is simulated physically at the multidirectional wave basin at OSU and the
wind is simulated numerically.”
The physical experiments will be conducted at the O.H.
Hinsdale Wave Research Laboratory, which is the largest nearshore experimental
facility at an academic institution in the U.S.
The Oregon State project is one of 13 selected by the DOE to receive a total of $28 million to advance wind energy nationwide. While utility-scale, land-based wind energy in the U.S. has grown to 96 gigawatts, significant opportunities for cost reductions remain, especially in the areas of offshore wind, distributed wind, and tall wind.
Erica Fischer, assistant professor of structural engineering, is working on a project funded by the Pacific Earthquake Engineering Research Center to evaluate which types of industrial facilities are vulnerable to collapse in fires that occur after earthquakes.
Traditional design approaches allow for the movement and bending of buildings but do not require fire suppression systems to be operable after an earthquake. This design method leaves many structures susceptible to fires after earthquakes because they do not have functional automatic fire suppression systems.
By varying ground accelerations under experimental settings and using Open System for Earthquake Engineering Simulation software for simulating the seismic response of structural and geotechnical systems, Fischer and her research group will quantify how much additional damage is caused by fire compared to the motion of the ground during an earthquake.
This project will identify vulnerable components of facilities and potential improvements by integrating seismological, multi-hazard, and socio-economical aspects of earthquake and fire engineering. Ultimately, Fischer is working to improve emergency management practice and help communities plan for their recovery after a disaster.
Earthquake Spectra, a leading journal on geotechnical engineering, recently published an article by Ben Mason, associate professor of geotechnical engineering in Oregon State University’s College of Engineering, recent graduate Rachel Adams, and colleagues from Caltech and Nepal. The article, Observations and simulations of basin effects in the Kathmandu Valley during the 2015 Gorkha Earthquake sequence, describes the Kathmandu Valley geology, analyzes motion from the initial earthquake and aftershocks, and identifies different factors responsible for the unusual ground motion that occurred in the region.
While publishing as a co-author is an accomplishment on its own, Adams had other notable achievements while at Oregon State.
During her graduate work, Adams accompanied Mason, her major advisor, on two research trips to Nepal. Their first trip occurred on the one-year anniversary of the Gorkha earthquake where Adams and Mason attended a workshop – with attendees from throughout the world – focused on reconstruction efforts. Through the gathering, they connected with Nepalese engineering professionals from government, academia, and industry who were eager to stay up to date on the best practices for their field.
“There is a large desire to improve education for engineering students and professionals, and consequently make improvements to infrastructure design and construction,” said Adams.
Through connections made with Nepalese colleagues, Mason and Adams identified topics for an earthquake engineering workshop, aimed at sharing current best practices on U.S. geotechnical engineering methods. In September of 2016, Mason, Adams, and researchers from other U.S. universities, presented the workshop at the National Society for Earthquake Technology – Nepal in Kathmandu.
“It was so valuable to interact with the engineering professionals in Nepal, and see their unique challenges for site investigations and construction in the very dense Kathmandu Valley,” said Adams. “We were there not only to teach and help to improve conditions, but to learn from them as well.”
Adams, who was an Evans Fellow in Oregon State’s Humanitarian Engineering program, participated in the Nepal activities with funding from the Evans Family Fellowship. The program supports research and travel for graduate work in humanitarian engineering through a generous donation from Dick and Gretchen Evans.
Much of the research in the Earthquake Spectra article employed data from previous trips to Nepal by Mason and the article’s lead author, Domniki Asimaki of Caltech. Together, they collected perishable data immediately following the earthquake – in an activity known as earthquake reconnaissance. As part of her graduate research, Adams worked with Mason and Asimaki on processing and reducing the data and making subsequent observations and interpretations. Essentially, the team investigated how the geology of the Kathmandu Valley changed the recorded earthquake motions, which is particularly relevant for the Willamette Valley of Oregon.
For Adams, who began her academic career at Chemeketa Community College in Salem, Oregon, the quest for knowledge and helping others took her to unexpected places.
“It was amazing to be able to be submerged in a culture so different from the U.S., but also discover that the people there had many of the same goals as us,” said Adams. “They have proved to be an extremely resilient community, which is a great example for the Pacific Northwest with the impending Cascadia Subduction Zone event.”
Earthquake Spectra, the professional journal of the Earthquake Engineering Research Institute (EERI), is published quarterly in both printed and online editions in February, May, August, and November. EERI established Earthquake Spectra with the purpose of improving the practice of earthquake hazards mitigation, preparedness, and recovery.
CCE faculty members Andre Barbosa and Christopher Higgins are participating in structural testing of a wood lateral-force resisting system, as part of the Framework Project, an anticipated 12-story tall wood building designed by Lever Architecture of Portland. Read more.
The PacTrans University Transportation Center recently released a five-minute video about a collaborative research/outreach project led by OSU CCE assistant professor David Hurwitz. The goal of the PacTrans outreach project featured in the video was to examine driver distraction among teenagers in the Pacific Northwest to identify tasks they consider to be distracting and compare that to their self-reported engagement in these same tasks while driving. The group, which includes members from all five PacTrans institutions, recently completed their first journal article, which has been accepted for publication.
During the video, Justin Neill, OSU MSCE ’14, is pictured operating the OSU driving simulator and Sarah McCrea, OSU second-year MS student, closes out the video.
The project was conducted at the O. H. Hinsdale Wave Research Laboratory as part of NSF’s NEES program. Co-authors include Prof. Rakesh Gupta in (College of Forestry), Prof. Dan Cox (College of Engineering), Prof. John van de Lindt (Colorado State University), Mary Beth Berkes (’10 Ocean Engineering), and Milo Clauson (College of Forestry).
This paper addresses tsunami loads on wood buildings through full-scale experimentation and is a crucial topic in the design of tsunami-prone structures, which has not received adequate attention in the field. The authors placed full-scale walls in a tsunami testing facility to investigate how a flexible structure performed when subjected to a solitary wave bore. The hydrodynamic conditions (water level and bore speed) and structural response (horizontal force, pressure, and deflection) were observed for a range of incident tsunami heights and for several wood wall framing configurations.
For each tsunami wave height tested, the force and pressure profiles showed a transient peak force followed by a period of sustained quasi-static force. The observed ratio of the transient force to quasi-static force was found to be close to 2.2. This value was compared with the measured forces with predictive equations from the literature and observed wood wall performance under such extreme loading. It was found that existing equations predicted the measured forces on the vertical wall within an accuracy of approximately 20%.
The study represents a significant step toward understanding the complex nature of wave structure interaction, particularly the performance of light-frame wood construction, which is commonly used around the world. Given the paucity of full-scale experimental data, the advances made by this paper are considered seminal and will most probably influence the field of tsunami engineering in the future.
The Raymond C. Reese Research Prize is awarded to the author or authors of a paper that describes a notable achievement in research related to structural engineering.
Photonics.com recently highlighted research conducted at the Oregon State University School of Civil and Construction Engineering with the discovery that algorithms could speed LiDAR assessments of landslide risks. An excerpt of the article appears below:
Created by researchers at Oregon State University and George Mason University, the Contour Connection Method (CCM) is based on lidar data and requires minimal user input. The developers say it can analyze and classifylandslide risk in an area of 50 or more square miles in about 30 minutes, a task that would otherwise take an expert several weeks to months to complete.