The attacks on September 11, 2001 were an extremely tragic event, and never before had we imagined two such prominent US landmarks and part of the Pentagon coming crumbling down before our eyes due to terrorism. Infrastructures, whether buildings, dams, or bridges, are often built with natural disasters in mind, but events like 9/11 have reinforced the need to design for man-made disasters, including terrorist attacks, incorporated into the construction processes. The Center for Extreme Events Research at University of California, San Diego (UCSD), advances the engineering research essential to protect critical infrastructure and bio-systems from extreme hazardous events. Leveraging interdisciplinary expertise to assess damage in extreme events such as mining explosions, landslides, car crashes and many other natural and man-made disasters, the center is well equipped not only to offer better protection of infrastructures but also to provide structural damage mitigation after events.

With experts spanning disciplines in structural engineering, mechanical and aerospace engineering, radiology, and mathematics, the center is home to the only “blast simulator” available in the field. This unique, explosive-free testing facility can shed light on designing and retrofitting structures to protect from damage, and provide data for creating enhanced computer simulations that help predict effects of larger-scale events. Led by Faculty Director Dr. Jiun-Shyan Chen, the center partners with many national defense and energy laboratories and industries to: 1. Protect the nation’s built infrastructure; 2. Provide rapid assessment of damage after disastrous events using simplified and reduced-order computational and experimental techniques; and 3. Prevent or mitigate brain and body injury due to blasts, crashes, and other stressful events.

More about the Center:

• Extreme Events Simulator and Gas Gun Facilities: The extreme event simulator is hardware that mimics how explosives hit structures. Conventionally, blast experiments would take place in the open field using real fire explosives, whose smoke hinders visibility and renders the experiment ineffective. Instead of fireball explosives, the blast simulator, designed by the Center Associate Director Dr. Hegemier, uses smoke-free, high pressure nitrogen based actuators to generate loads that simulate real blasts up to 12,000 psi-msecs, that enables indoor experiments with high-speed cameras installed in strategic places to analyze the “progressive failure” of the structure thoroughly. Likewise, the gas gun facilities, with Center Faculty Dr. Kim leading the effort, provide similar advantages, and enables world-class projectile impact and penetration research focused on impact effects on composite materials and aerospace structures.
• Advanced Computational Simulation Technology: Previously, conventional methods of constructing simulation models depended on the “mesh” function to describe a structure such as a column or a wall. However, modeling penetration or fragmentation using a mesh was extremely difficult, as the mesh would often become distorted and inaccurate. Dr. Chen, Director of the Center, was one of the original developers of the “Meshfree” computational methods for modeling materials and structures subjected to extreme loading conditions. Using points to describe the geometry of the structure instead of a mesh, the Meshfree method can model large deformation and multi-body contact, shock waves, fracture and damage mechanics, high strain rate fragment-impact processes, biosystems, as well as multi-scale mechanics and materials. Another unique computational simulation technology available at the center is the Isogeometric Analysis pioneered by the center Associate Director Dr. Bazilevs. Isogeometric analysis employs complex NURBS geometry (the basis of most CAD packages) in the FEA application directly. This allows models to be designed, tested and adjusted in one go, using a common data set.