Project Abstracts: 2008 to 2009
Structural Engineering and Mechanics
Calibration of Rutting Models for HMA Structural and Mix Design
Y.R. Kim and M.N. Guddati;
NCHRP 9-30A, Subcontract from Applied Research Associates, Inc. (11/05 to 10/08)
The objective of this research effort is to recommend revisions to the HMA rut depth prediction model in the mechanistic-empirical pavement design guide and software developed in NCHRP Project 1-37A for consideration by the NCHRP Project 1-40 panel and the AASHTO Joint Task Force on Pavements. The recommended revisions will be based on the calibration and validation of distress models with measured materials properties and performance data from existing field and other full-scale pavement sections that incorporate modified as well as unmodified asphalt binders.Parameter Determination for
Parameter Determination for Chaboche Model in ANSYS Finite Element Software Package for Two Materials
Tasnim Hassan; Honeywell International, Inc. (11/07 to 08/09)
Honeywell Aerospace of the Honeywell International is attempting to develop design methodology for turbine or compressor disk that is successively taken to higher and higher strains in a spin test (through higher and higher rotational speeds) until the disk bursts. The ratcheting mechanism is involved in this progressive failure. However, the ratcheting mechanisms of the involved materials, PM Astroloy and forged Ti-6-4, are not known. In addition, the parameters of the Chaboche model which will be used in the finite element analysis for design development are not known. Through this project a set of experimental responses (experiments to be conducted by Honeywell Aerospace) and Chaboche model parameters for structural analysis will be developed.
A Multiscale Study of Ratcheting Failure Mechanisms in Austenitic and Ferritic Steel Welded Joints
Tasnim Hassan and K.L. Murty; National Science Foundation;
(08/04 to 01/09)
The goal of the project is to study multiscale failure mechanisms of austenitic and ferritic steel welded joints subjected to low-cycle fatigue loading. The progressive accumulation of strain with cycle known as ratcheting is believed to result in unexpected failures of defect-free joints. This project will perform low-cycle fatigue tests of welded joints and transmission and scanning electronic microscopy studies of dislocation substructures of the heat affected zone and base metals at various stages of fatigue life. Efforts will be made to develop a model for simulating ratcheting responses of welded joints using both macroscale and multiscale based constitutive models.
SST: Polymer Waveguide Sensors for Performance-Based Assessment and Health Monitoring of Civil Infrastructure Systems
Tasnim Hassan, M.J. Kowalsky and K. Peters; National Science Foundation (08/04 to 07/08)
The goal of the project is to develop polymer sensors for health monitoring of civil infrastructure systems. Of specific interest is to develop a sensor that can measure strains in excess of 6% under high strain rates. Although the sensors to be developed can be utilized under a variety of load conditions and structural materials, this research program will focus on application of the sensors to concrete and steel structures subjected to earthquakes loads. The research will develop a data acquisition system that can be utilized in health monitoring and techniques for bonding the polymer sensors to concrete structures.
Hot Mix Asphalt Performance-Related Specifications Based on Viscoelastoplastic Continuum Damage Models
Y.R. Kim and M.N. Guddati;
DTFH61-08-H-00005, Federal Highway Administration (02/08 to 02/12)
Models developed at NCSU over the years provide a unique opportunity to develop a mechanistic Performance-Related Specification (PRS) for hot mix asphalt (HMA) mixtures. This project will focus on development of different analytical and experimental tools that can be used for the development of the HMA-PRS. The HMA-PRS will be hierarchical in nature; that is, a higher level specification uses more complete and accurate test and analysis methods, which requires more sophisticated testing.
Multiscale Modeling of Asphalt Concrete for Fatigue Cracking Evaluation
Y.R. Kim and M.N. Guddati;
Texas A&M Research Foundation/FHWA (12/06 to 11/11)
Work at WRI-TTI-NCSU under previous funding directed by FHWA has developed continuum damage and micromechanics models of fatigue damage in asphalt mixtures/pavements. In the proposed study, these models will be refined and a wide range of materials and conditions will be tested. The primary objective of the proposed research is to understand the fatigue cracking phenomena in asphalt concrete at multiple scales from which material specifications and design methods would be developed.
Development of a Seismic Fragility Methodology for Nuclear Power Plant Structures
Marty McCann Jr. (Stanford University), Abhinav Gupta (NCSU), and Jack Baker (Stanford University);
Kajima Corporation of Japan through CUREE/Kajima Partnership (2009 to 2011)
The purpose of this study is to develop and implement a generalized seismic fragility methodology for structural components and systems. The study will develop an approach that provides a closer integration of the characterization of earthquake ground motions and the performance of critical facilities. This research is aimed at developing an approach that takes advantage of Kajima structural analysis capabilities and integrates an improved characterization of earthquake ground motions with a detailed reliability analysis of structure performance. The work is being conducted jointly by a multi-institutional team of researchers from NC State University, Stanford University, and Kajima Corporation of Japan.
NEESR-GC: Simulation of the Seismic Performance of Nonstructural Systems
A. Gupta and M. Margakis (University of Nevada, Reno); other participating institutions: SUNY-Buffalo, UC-San Diego, Cornell, GA-Tech, NC A&T, and UNC-Chapel Hill;
(Project Managed by: CUREE) (2007 to 2012)
Overall objective is to study the seismic performance of non-structural ceiling systems in buildings such as fire suppression piping, suspended ceiling fixtures, HVAC ducts, and partitions. NCSU’s work is focused on computer modeling, optimization, and fragility evaluations for designing piping configuration needed to conduct experiments, Subtasks of this study focus on verification of theoretical formulations for seismic analysis of coupled building-piping systems as well as development of new formulations for improved verification with respect to the experimental results obtained by other participating organizations.
Load Combination Method and Analytical Methodology for IRWST and Other Dynamic Loads in Piping Analysis
A. Gupta;
Korea Power Electric Company, KOPEC, South Korea (2008)
This project is aimed at providing technical knowledge on state-of-the-practice for combining various dynamic loads such as those due to Earthquake, Loss of Coolant Accident (LOCA), and Safety Relief Valves (SRV) in a nuclear power plant piping system analysis. This work has different aspects that relate to: (a) Providing background information on the currently specified load combination procedures in USNRC recommended and ASME recommended guidelines, (b) Theoretical basis for various recommendations, and (c) Train KOPEC engineers on incorporating appropriate load combination methods in an actual piping analysis and assist them with interpreting the results.
Effect of Load History on the Seismic Performance of RC Members
M. J. Kowalsky and J.M. Nau; Alaska DOT (08/08 to 07/11)
There are two related problems in this research via large scale experimental testing and fiber-based and solid-element based analysis. Most well detailed modern reinforced concrete sections fail by buckling of reinforcement. In design, engineers relate strains to displacement via monotonic section analysis, however, earthquakes impose cyclic loading on structural systems. As a result, strain limits that are currently utilized can be correlated to different displacement limits depending on the load history the structure is subjected to. There is a need to propose strain limit states that account for low temperature effects and regional seismic load histories, and develop an approach for AKDOT engineers to easily relate proposed strain limits to target displacements for design.
Seismic Performance of Spirally Welded Pipe Piles
M. Kowalsky and Tasnim Hassan;
Skyline Steel Corporation (04/07 to 07/09)
Spirally welded pipe piles are manufactured in a manner that may result in various categories of welded joints any of which at or near the plastic hinge zone of a pile may determine its seismic performance. The location of the plastic hinge zone in the ground will depend on the stiffness of the soil, ground temperature, and pile diameter. This project will conduct experiments to determine the load-displacement responses under the AISC 341 load protocol, Appendix S, as well as to determine failure mechanisms for these three welds located at the plastic hinge of the pile.
Ductility of Welded Steel Column to Cap-Beam Connections
M. Kowalsky, Tasnim Hassan, and J.M. Nau; Alaska Department of Transportation (08/07 to 07/09)
This research will assess the ductility of a commonly used steel pipe-column to steel cap-beam connection used in Alaska for bridge and dock structures. The final goal is to develop recommendations for ductility capacity of the existing connection detail and for an alternative detail capable of sustaining the design ductility level while allowing for inspection. Recommendations will be provided for both current force-based design as provided in the 2004 AASHTO LRFD specifications (force reduction factors, ductility limits, displacement amplification factors) as well as for displacement-based design (target displacements and equivalent damping) as is being developed for future AASHTO bridge specifications.
Modeling the Impact and Blast Performance of Fiber Reinforced Concrete
V.C. Matzen and Abhinav Gupta;
Idaho National Laboratory
(2006 to 2009)
This study is aimed at providing an experiment-based application for the blast/impact software investigation to be carried out at INL. An active research collaboration between INL and the Center for Nuclear Power Plant Structures, Equipment and Piping at NCSU is proposed. The collaboration will provide NCSU personnel an access to the advanced finite element software available at INL to model the structural performance of FRC. Simple experiments on FRC structural members will be conducted at NCSU for reconciliation of analytical and experimental results. The purpose would be to help in the development of new FRC material to withstand impact and blast loads.
Procedures for Multi Hazard Risk Assessment in Civil Infrastructure Systems
R. Ranjithan, D. Brill, J. Baugh, Mo Gabr, M. Overton, and R. Seracino (05/08 to 12/10)
The pilot project will develop an outline of a multihazard risk assessment methodology associated with floods and levees. It will also identify model requirements and data needs. This work will serve as a prototype for future work to develop a more comprehensive methodology for considering a broader range of natural hazards and civil infrastructure.
Engineering to Enhance the Resilience of the Built and Natural Environments
R. Leuttich (UNC-CH), M. Overton, G.F. List, R. Seracino, M. Gabr, R. Ranjithan, D. Brill, and J. Baugh
Department of Homeland Security, Center of Excellence (08/08 to 07/14)
The objective is to investigate innovative and proactive approaches to plan, design and construct CCI components to provide services needed to increase disaster preparedness and resilience of the integrated CCI system, as well as to protect the natural environment. To achieve this goal, five highly interrelated research projects are being proposed. Each project has a project leader and anticipated partners; however, the projects are proposed as complementary pieces contributing products to be used to meet the overarching objective to enhance the resilience of the built and natural environment, a single objective. As such, project leaders will work together to coordinate efforts, align case studies, transfer outcomes, develop scenarios, etc. toward a highly integrated product.
I/UCRC Center, “Repair of Buildings and Bridges with Composites (RB2C)” – Three Year Extension
S. Rizkalla;
National Science Foundation (08/07 to 08/10)
The NSF Industry/University Cooperative Research Center entitled “Repair of Buildings and Bridges with Composites” (RB2C), is located at the Constructed Facilities Laboratory, North Carolina State University (NCSU). The Center is working in collaboration with the Center located at the University of Miami, Florida. The Center at NCSU focuses on the needs of the construction industry in development of new and innovative structural components as well as strengthening/repair methods for existing structures using advanced composite materials.
Torsional Strengthening of Concrete Structures Using Near Surface Mounted Fiber Reinforced Polymers
Australian Research Council;
R. Al-Mahaidi (Monash University) and S. Rizkalla (07/07 to 07/10)
The proposed study focuses on the torsional strengthening of concrete flexural members in bridges and buildings using Fiber Reinforced Polymers (FRP). Since the mid 1980s, a significant number of studies on flexural and shear strengthening of beams and axial strengthening of columns have been performed. The area of torsional strengthening has received little attention and thus no reliable data exists to enable the incorporation of the topic in design guidelines. The proposed study will fill the gap that currently exists in the FRP strengthening of RC structures. It will also provide the engineering community with analytical tools for the design of FRPs in torsional strengthening applications.
Evaluation of Bond Characteristics of MMFX Steel
S. Rizkalla;
NSF – I/UCRC - RB2C - MMFX Technologies Corporation (07/05 to 12/09)
The high-strength steel commercially known as Micro-composite Multi-structural formable (MMFX) steel could lead to potential savings through the use of lower reinforcement ratios due to it’s higher strength. The proposed research will investigate the bond behavior of MMFX steel to concrete. The first phase of the proposed research program will include the parameters believed to significantly affect the bond strength: concrete compressive strength, bar size, concrete clear cover, and confinement level. Three universities are participating in this study, namely, University of Texas at Austin, The University of Kansas, and North Carolina State University. Each university will test twenty-two full-scale splice beams for the first phase of the program.
Development of Rational Design Methodology for Precast, Prestressed Concrete Spandrel Beams
S. Rizkalla & P. Zia;
NSF - I/UCRC - RB2C – Precast/Prestressed Concrete Institute (07/06 to 06/09)
The goal of the proposed research is to develop appropriate design procedures and to simplify the detailing requirements for precast, L-shaped spandrel beams. The research includes an extensive experimental program designed to test prototype precast L shaped spandrel beams and an analytical phase based on non-linear finite element techniques.
Developing a Telematics Platform for Bridge Monitoring and Health Prognositcs
S. Rizkalla;
National Science Foundation (Supplement to RB2C Center) (07/07 to 06/09)
The approach proposed in this TIE project integrates the extensive research on physics of bridge damages and instrumentation of bridge monitoring system, conducted at the RB2C Center, with the feature-based smart prognostic agent, namely the Watchdog Agent® developed by the IMS Center, to accurately quantify and predict bridge deterioration. The major merit of this work will be the initiation of a combined physics-statistics-based prognostics approach, which expands and integrates the theories and tools developed in RB2C and IMS. The developed methodology will bring about innovation to predict bridge deterioration and provide a general framework for prognostic bridge health management for next-generation intelligent transportation maintenance systems.
Basalt Fiber Reinforced Cementitious Matrix Composites for Infrastructure Repair
S. Rizkalla;
National Science Foundation (Supplement to RB2C Center) (07/07 to 06/09)
The project focuses on the strengthening and upgrade of existing reinforced concrete (RC) structures using a new class of composites made of basalt fibers embedded in a cement-based matrix (BFRC). Basalt fibers are manufactured in a single-stage process by melting naturally occurring basalt rock. The BFRC confining system represents a promising solution to overcome limitations of current fiber-reinforced-polymer (FRP) systems that make use of carbon or glass fibers impregnated with an epoxy resin. The research will first study the mechanical and durability performance of commercial grade basalt fibers and then of the system obtained by combining them with the cementitious matrix.
Strengthening In-Fill Brick Walls with Composite
S. Rizkalla;
E. Fyfe Company (07/07 to 06/09)
This research is designed to examine the effectiveness of various strengthening techniques for In-fill brick walls using glass fiber reinforced polymer material. The experimental progress consists of fourteen full-scale In-fill brick wall unites subjected to uniform pressure to simulate the pressure and extreme wind loading conditions. Various constraints and anchorage systems were included.
Behavior of Concrete Sandwich Panels Reinforced with CFRP Grid
S. Rizkalla;
AltusGroup (08/06 to 07/08)
The objective of the study is to determine the behavior of prestressed concrete sandwich panels under the effect of gravity and simulated wind loading conditions. The panels are reinforced transversely by a new innovative carbon fiber reinforced polymer to achieve composite action under the combined gravity and wind load. The research consists of an experimental program which included testing of six full-scale sandwich panels varying from 20 to 40 feet. All panels will be tested under fatigue and monotonic loading conditions to failure.
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