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NatHaz(Natural Hazards) Modeling Laboratory

Ahsan Kareem

Description

The mission of this laboratory is to quantify the load effects caused by various natural hazards on structures and to develop innovative strategies to mitigate and manage their effects.

Problems we are working on

 Damping Systems
 Dynamics of Long-Span Bridges & Tall Buildings
 Full-Scale Monitoring of Structures
 Wind Tunnel Modeling
 Dynamic Load Simulator/Hardware-in-the-Loop
 System Identification
 Modeling, Analysis and Simulation of Random Processes: Applications to Wind, Waves and Earthquakes
 Modeling of Transient Events : Gust/Wave Fronts
 Wind and Wave Effects on Offshore Platforms
 Natural Hazard Risk Analysis and Management
 Codes & Standards
 IT and Networked Sensing Devices

This diversity allows the laboratory to address challenges in the design and construction of structures experiencing loads due to wind/wave/earthquake. This includes modeling of loads, analysis of structural response and mitigation measures by means of improved design. Through analytical/computational, scaled experimental studies, and full-scale monitoring the Laboratory has been able to make important contributions in fundamentals through applications. The NatHaz Modeling Laboratory offers a comprehensive research platform for R&D related to dynamic load effects & their mitigation and management of civil infrastructure.

Facilities

The laboratory has various laboratory scale experimental set-up for modeling dynamic load effects. These are in tandem with the Atmospheric Wind Tunnel in the Hessert Center for Aerospace Research which has the wind tunnel facilities.

The Dynamic Load Simulator (DLS) is set-up with a two-level model connected to 2 actuators which can dynamically load the structure with correlated wind, wave and earthquake loading.

 A 2-story building module Quanser Consulting with an Active Mass Damper (AMD) module for verification of control strategies. Two small Shaking Tables are also installed in the laboratory to conduct experiments for simulation of earthquakes and basic dynamics studies.

A Tuned Liquid Damper (TLD) which is a type of TMD where the mass is replaced by a liquid (usually water).

The laboratory also includes a network of instrumented tall buildings in Chicago that includes conventional instrumentation, e.g., accelerometers, ultrasonic anemometers and real-time kinematic(RTK) high precision GPS system.

Hammer kit from Modal Shop is available for modal analysis and SIGLAB (DSPT technology) is used for MATLAB based time-domain and spectrum analysis. The laboratory also has various data acquisition and control implementation software like DSpace, WinCon and LabView. Computational resources include four dedicated pentium computers for data acquisition and a SunSparc UltraUnix workstation for analysis. The labaratory also has a wide range of sensors ranging from laser sensor displacement sensors, 6 degree-of-freedom load cells, pressure transducers, accelerometers, LVDTs, etc. and associated signal conditioning units and synchronous pressure measurement system.

Projects

  Full-Scale Monitoring of Tall Buildings
  Aerodynamic Loads Database : An Interactive Database
  Aerodynamics of Tall Building and Long-Span Bridge
  Wavelet Analysis / System Identification
  Damping Systems : TLD and TLCD
  Real-Time Model Predictive Control(MPC)
  Design of Floating Offshore System : Tension Leg Platform(TLP)
  Stochastic Dynamics / Simulation & Modeling
  Dynamic Load Simulator / Hardware-in-the-Loop
  Wind Load Effects in Gust Fronts
  Codes & Standards and Design Tools

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