Computer-Aided Engineering

Research Project Abstracts: 2003 - 2004

Interrelationships Between Success and Learning Strategies Applied by Engineering Students
L.E. Bernold
National Science Foundation
07/02 to 06/04
This project investigates the study skill and habits of Engineering Freshmen in order to identify deficiencies that can be remedied. One of the key goals is to help more of the failing students, 43% in the first year in college, to succeed by empowering them to learn efficiently. The first papers that have been published have received two best paper awards at international conferences.

Field Studies with Innovative Safe Excavation Technologies
L.E. Bernold
National Institute for Occupational Safety and Health
09/01 to 10/04
Trenching and pipe-laying are some of the most dangerous operations in construction. This project is designed to address this issue by eliminating the need for laborers to enter the trench at all. In the three year study, we will design and build the necessary hardware and test its effectiveness in the field. Also included in the work is the further development of an innovative buried utility detection system that will provide the operator the means to scan the ground before any digging motion.

Efficient Computational Methods for Accurate Simulation of Wave Propagation
M.N. Guddati
National Science Foundation
08/16/01 to 08/15/04
Wave propagation is encountered in countless problems of practical importance such as nondestructive evaluation, earthquake engineering, seismology and medical imaging. In spite of its immense importance and extensive research performed, the current approaches to modeling of wave phenomenon still suffer from several shortcomings related computational efficiency and accuracy. This project is aimed at devising new and efficient modeling techniques that would result in highly accurate solutions with relatively low computational cost. Most recent results from this research are related to dispersion reducing finite element methods and absorbing boundaries.

Numerical Simulation of Bridging and Tip-Screenout in Hydraulic Fractures
M. N. Guddati
Schlumberger Oilfield Services
08/01/02 to 12/31/03
Bridging of proppant particles in a hydraulic fracture can lead to the phenomena of tip-screenout that results in reduced productivity of oil and gas wells. This project is aimed at accurate modeling of rock fracturing, slurry flow in the fracture, along with the complicated nonlinear coupling. Such modeling will be performed by innovative mixture theory based formulation developed by the PI, along with some semi-analytical modeling of hydraulic fracture tip. At the end, it is expected that the modeling procedure would be able to accurately predict the bridging process and eventually tip-screenout.

Development of Specification Testing to Promote Fracture Fatigue Resistance and to Optimize Microdamage Healing
Y.R. Kim and M.N. Guddati
FHWA/WRI/Texas A&M Research Foundation
07/01/99 to 12/03
The ultimate goal of this project is "to be able to classify/specify/improve asphalts by their healing rates and efficiencies using chemical data that can be acquired more rapidly than by mechanical methods." To accomplish this goal, the viscoelastic, continuum damage model developed by the PI will be tied to the micro-mechanical properties of component materials using DM2, a discrete element code developed by the Co-PI. Various test methods will be explored for binder specification testing using the viscoelastic, continuum damage formulation and DM2 simulation with an objective to promote fatigue resistance and to optimize the microdamage healing potential.

Characterization of ALF Mixtures Using the Viscoelastoplastic Continuum Damage Model
Y.R. Kim and M.N. Guddati
Federal Highway Administration
08/15/03 to 08/14/05
The primary objectives of the proposed research are: (1) to verify the time-temperature superposition principle in damaged states for various asphalt mixtures used in the current ALF study; (2) to characterize the ALF mixtures using the viscoelastoplastic continuum damage model; and (3) to predict the performance of various ALF pavements using finite element analysis and the VEPCD model.

Inverse Wave Propagation Algorithms
M.N. Guddati
Unsponsored
09/01 to current
Wave-based inversion is used in many fields of engineering including nondestructive evaluation, seismic imaging, seismology and medical imaging. In many cases, the extensive experimental data is processed by the inverse solution of the wave propagation problem to predict the underlying domain properties. These existing solution methods are either very approximate or extremely expensive. This project attempts to devise a method that will provide an efficient and accurate alternative to the existing data processing algorithms.

Semi-Analytical Modeling of Fractures in Layered Media
M.N. Guddati
Unsponsored
10/03 to current
Proper understanding of fracture growth in layered media is of significant importance in various engineering problems of economic significance (cracking of laminated composites, hydraulic fracturing in the context of petroleum engineering and geophysics, to name a few applications). This project aims to develop an extremely efficient alternative to the existing numerical methods such as finite element and boundary element methods. An appealing feature of the resulting method is expected to be an approximate modeling procedure of slippage between un-bounded layers, a phenomenon that can have considerable effect on fracture growth.

Multi-level Computational Modeling of Damage and Failure
M.N. Guddati
Unsponsored
02/00 to 08/03
The phenomena of failure and damage of engineering materials span a wide range of spatial and temporal scales. Recent advances in computing power and micro-mechanical modeling research make it feasible to investigate the local behavior of failure and damage of heterogeneous materials with the use of computational models. However, simulating global mechanisms using micro-mechanics-based models is not efficient, even when it becomes feasible. This project involves exploratory investigation of multi-level algorithms to simulate failure and damage of large heterogeneous systems. On one extreme, these algorithms are expected to emulate homogenized continuum models, and on the other extreme, they emulate detailed micro-mechanical models.

Internet-Enable Laboratory Experiences for Undergraduate Civil Engineering Students
V.C. Matzen, M. Gabr, and Abhinav Gupta
National Science Foundation
07/03 to 06/05
This study is aimed at adaptation of recent developments in information technology for incorporation of internet-enabled civil engineering laboratory experiments in undergraduate structures and geotechnical courses. Faculty and students will be able to remotely access, run, and control these experiments either independently or in a classroom setting. Such a capability would facilitate the offering of these courses via distance learning program to provide opportunities for "non-traditional" students (e.g., part-time student, working parent, and career-changing adult) seeking careers in Civil Engineering. Implementation of this work will lead to enhancing the quality of undergraduate Civil Engineering courses and making laboratory curriculum widely accessible.

Remote Observation and Control of a Shake Table Experiment
Abhinav Gupta, V.C. Matzen, and M. Gabr
NC State University, DELTA/IDEAS Grant
07/03 to 06/04
This project supports tasks that are needed in addition to those being conducted in development of a prototype for remote observation and control of a shake table experiment under an NSF sponsored project. These tasks are needed to integrate the prototype with the University computing network for incorporation in distance education courses. The tasks need to be implemented in a manner that would maintain real-time safety as well as security features built into the prototype. While the tasks being undertaken are specific to the shake table experiment, the outcome of this work can be extended to other experiments either directly or with only minor modifications.

Computer Programs CREST and INCABS
Abhinav Gupta
Center for Nuclear Power Plant Structures, Equipment and Piping
01/02 to 12/03
This project continues to study the effects of uncertainties in the various primary and secondary system parameters on the coupled primary-secondary system response. A method is being developed to account for these uncertainties in CREST as well as INCABS. The purpose is to facilitate the use of CREST and INCABS in a risk-informed environment for design and operability. It is anticipated that such an implementation would be helpful in identifying minor structural modifications of cabinets and control panels that may significantly reduce cabinet amplifications and facilitate the use of commercial grade equipment.

Decision Support for Seismic Performance Evaluation
Abhinav Gupta, J. Baugh, and G. Mahinthakumar
National Science Foundation
09/00 to 08/03
Overall goal of this research is to develop formal computational approaches that support comprehensive decision making in structural engineering. Specifically, these approaches are being realized in a prototype decision support system that draws on complementary strengths of the engineer and the computer in a joint-cognitive system. Its design is based on three major concepts: (1) optimization for evaluating alternatives and supporting what-if analyses; (2) sub-component approach to address structural model synthesis, scalability, model updating, and uncertainty propagation; and (3) implementation in an object-oriented framework of high performance distributed computing. A series of simple and real-life test cases are being used to evaluate the proposed prototype.

Optimizing Moment Connections in Steel Frame Buildings Subjected to Dynamic Loads
Abhinav Gupta and D. Laefer
Unsponsored
Ongoing
This research focuses on optimizing the number of moment connections in steel frame buildings. High performance computational tools will support an iterative decision process by finding not only an optimal solution but also meaningful alternatives to allow better consideration of uncertainty and tradeoffs among objectives. Alternatives will be assessed with respect to margins associated with design and serviceability requirements, redundancy, assembly depth, and schedule related constraints. Advisory board members will comment on constructability, field welding, compatibility with floor framing work, sensitivity to field modifications, OSHA regulations for erection, and other "intangibles" that may depend upon schedule and site related constraints.

ITR: A Prototype to Support Near Real-Time Environmental Characterization
G. Mahinthakumar (with Ranji Ranjithan and Nick Karonis)
Information Technology Research Program (ITR), NSF
09/03 to 08/06
The overall goal of this project is to investigate formal computational approaches that can readily harness grid computing for the efficient solution of environmental characterization problems. To this end, we will develop a grid-enabled software framework. Two alternative paradigms, one based on the grid-enabled version of MPI (Message Passing Interface), and the other based on Java will be explored. The framework will be applied to groundwater and surface water problems, both of which are of prime societal importance.

High-end Computing In Environmental Engineering with Application to Subsurface Characterization (CAREER)
G. Mahinthakumar
$400,000
07/01/03 to 06/30/08
Accurate characterization of the subsurface is an important element in the development of reliable and efficient groundwater management practices. Accurate and reliable estimation of hydraulic conductivity distribution, contaminant distribution, and/or contaminant source release history is necessary for problems such as estimating groundwater yields, design of efficient cleanup strategies, and identifying responsible parties in a contamination incident. This requires solution of an inverse problem because direct measurement of detailed subsurface properties is not feasible. Inverse problems are difficult to solve and are computationally demanding. This multidisciplinary CAREER project will investigate novel computational strategies for the efficient solution of large-scale inverse problems in subsurface characterization.

High End Computer System Performance: Science and Engineering
UT Battelle LLC
G. Mahinthakumar
10/24/01 to 09/30/04
The project involves 10 major institutions with Lawrence Berkley National Lab and ORNL as the lead institutions. The overall goal of the proposal is to establish an Enabling Technology Center (ETC) in the area of high-end computer performance. The NCSU research will focus in two areas: 1) performance modeling and analysis and 2) benchmark development for a large-scale parallel astrophysics application. Several modern high-end computer systems including the IBM SP, Compaq Alpha/SC, and an Intel Itanium Linux Cluster will be employed in this research.

Development and Performance Testing of a Large-Scale Parallel Groundwater Flow and Transport Code
G. Mahinthakumar
Unsponsored
01/00 to present
We have developed a parallel groundwater flow and transport simulator intended for high-resolution numerical simulations involving multicomponent groundwater transport and remediation. The main feature of the code is that it can solve very large problems (in the order of 10's of millions of cells) efficiently on today's parallel supercomputers. We will continue with the development and performance testing of this code on the latest parallel computers including those at ORNL, SDSC, NERSC, and NCSA.

Hybrid Global-Local Approaches Enabled by Parallel Computing for Solving PDE Governed Inverse Problems in Civil Engineering
G. Mahinthakumar
Unsponsored
01/02 to present
We are investigating the use of hybrid global-local search approaches for solving large-scale PDE governed inverse problems in civil engineering. Our current focus is on groundwater source identification inverse problems. The approaches developed through this research, however, are more general and can be applied other types of civil engineering inverse problems such as damage detection in structures and air pollution source-matrix identification. We are using genetic algorithms (GAs) as our global search approach and are investigating several local approaches such as Nelder-Meade simplex method, Levenberg-Marquadt method, and Sequential Quadratic Programming.

B2 Stress Index for Cyclic Loading
V.C. Matzen
Center for Nuclear Power Plant Structures, Equipment and Piping
01/03 to 12/03
Piping design in nuclear power plants is normally carried out using linear elastic analysis and simplified equations to ensure that the piping system and components don't fail under normal or sever loadings. One of the failure modes considered is low-cycle fatigue that might occur during an earthquake. The ASME Boiler and Pressure Vessel Code committees have recently modified the design equation related to this failure mode. Our research will help define one of the parameters, B2', that occurs in that equation. The research will involve shake table experiments and nonlinear finite element analysis.

Traffic Control Design for Portable Concrete Barriers
A. Mirmiran and S. Rahman
North Carolina Department of Transportation
07/04 to 06/05
This newly funded project will focus on developing design aids and charts for portable concrete barriers in the state of North Carolina. Safe back distance behind these free standing barriers will be evaluated using finite element and impact analysis software for different boundary conditions and traffic configurations. The findings will be incorporated into the state's traffic control manual.

Using Digital Shoreline Data to Better Characterize Inlet Processes and Near-Term Shoreline Behavior
M.F. Overton and J.S. Fisher
NC Division of Coastal Management
08/14/02 to 09/30/04
The Division of Coastal Management (DCM) has identified a need to characterize the significant processes impacting North Carolina's inlets and adjacent oceanfront shorelines within the Ocean Erodible Area (OEA). To adequately characterize these processes, short-term shoreline trends need to be documented. This project will undertake to develop as many digital shoreline datasets as possible from both historical (e.g., aerial photography, Tsheets) and modern sources (LIDAR, photography based digital terrain models, orthophotos). Given the temporally robust set of digital shorelines proposed in this work, shoreline change models can be improved and a framework for understanding the short-term changes can be developed.

Shoreline Monitoring at Oregon Inlet
M.F. Overton and J. S. Fisher
NC Department of Transportation
07/03 to 06/04
The purpose of this ongoing project (1989 to present) is to monitor and evaluate the response of a six mile stretch of shoreline just south of the terminal groin constructed to protect the bridge at the north end of Pea Island. The purpose of phase one was to establish the 'historical erosion rates' for the study area since the change in dredging operations in the inlet in 1984 and before the March 1989 storm. The continuing phases of the project consist of determining position of the shoreline from air photography every two months and evaluating the response of the shoreline in the context of the historical erosion rates.

Fuzzy Neural Network Models for Geotechnical Problems Encountered by NCDOT
S. Rahman
NC Department of Transportation
$97,841
07/04 to 12/05
The main objective of the proposed research is to: (i) develop a general framework and a computational toolbox for development of fuzzy neural network models to geotechnical problems, and (ii) to develop fuzzy neural network model for a variety of geotechnical problems of interest to NCDOT: (a) hammer approval, and (b) settlement prediction.

Solid Waste Management Life-Cycle Inventory (SWM-LCI) Model Capabilities
M.A. Barlaz and S.R. Ranjithan
Delaware Solid Waste Authority
9/03 to 8/04
The objective of this project is to develop alternatives for the management of municipal solid waste for the State of Delaware. Alternatives will be developed to examine tradeoffs among cost, environmental burdens, resource consumption and landfill diversion using a solid waste management life-cycle inventory model developed by the investigators. After identification of a select group of alternatives, their robustness will be evaluated using the uncertainty component of the life-cycle model.

Urban Watershed Management Tools
S. Ranji Ranjithan
US EPA/MCNC
10/01 to 09/04
U.S. EPA's Multimedia Integrated Modeling System (MIMS) provides a unified computing framework to simulate the cycling of environmental pollutants within and across all media. The simulation models are to be coupled with systems analytic methods (including uncertainty analysis and optimization-based search procedures) to explore and identify efficient strategies to manage urban watershed management problems. In addition, decision-makers require cost/benefit tradeoffs and reliability associated with different strategies. The objective of this project is to integrate urban watershed decisions support tools into MIMS, and demonstrate their use with US EPA's Storm Water Management Model (version 5).

Tools and Techniques for the Technological Integration of Multi-Hazard Post-Incident Assessment
D. Laefer and W. Rasdorf
National Science Foundation
12/15/03 to 09/30/04
The purpose of this project is to organize and present a workshop to assist in obtaining solutions for the problems addressed in the following abstract submitted to NSF for possible funding. Infrastructure management information systems (IMISs) are being created with ever greater rapidity, at all levels of government and private industry. These IMISs are, however, dispersed, stand-alone, in widely disparate formats, not reflective of historical developments, and not easily identified or readily accessed. Thus, they do not promote information exchange between agencies and organizations that would profoundly benefit from shared resources, especially in this time of acute budgetary constraints.

Designing and Efficient Nighttime Sign Inspection Program that Ensures Motorist Safety
W. Rasdorf and J. Hummer
NC Department of Transportation
07/01/04 to 06/30/06
The major objective of the research is to revise and expand out simulation of the effectiveness of sign inspection programs so that NCDOT can optimize its program. The main revisions to allow NCDOT to use the simulation are to:

Life Cycle Inventory and Impact Analysis Framework for Nonroad Construction Vehicles and Equipment
H. Christopher Frey and W. Rasdorf
National Science Foundation
09/03 to 09/04
The objectives of this work are to: (1) Characterize the second-by-second in-use emissions and energy use of nonroad construction vehicles and equipment, including emissions of nitric oxide, carbon monoxide, hydrocarbons, carbon dioxide, and particulate matter, including real time sensing and monitoring where needed to fill data gaps; (2) Develop a life cycle inventory of conventional nonroad construction vehicles and equipment; and (3) Identify and recommend methods for reducing energy use, emissions, and impacts.

North Carolina Forecasts for Truck Traffic
J.R. Stone
North Carolina Department of Transportation
07/03 to 12/04
Estimates of truck traffic are critical parameters in designing and maintaining highway pavement and structures. National databases suggest that trucks are becoming an increasingly larger proportion of traffic. Anecdotal reports suggest that North Carolina truck traffic is increasing in excess of national averages. Consequently designers apply generous adjustments for forecast truck traffic. However, over estimates lead to over design and unnecessary construction cost. This project helps resolve these issues through improved data collection, display and analysis techniques.

A Mechanistic Approach to Evaluate Contribution of Prime and Tack Coats In Composite Asphalt Concrete Pavements
A. A. Tayebali and S. Rahman
NC Department of Transportation
07/01/00 to 12/31/03
The importance of proper AC layer interface bonding cannot be overemphasized for good performance of AC pavements. A strong bonding between layers is critical to dissipate shear stresses into the entire pavement structure. Lack of bonding may cause slippage phenomenon and activate distress mechanisms that will rapidly lead to total failure of the pavement. The objective of this study is to evaluate the effects of different prime and tack coats on the bond strength in relation to the thickness of the asphalt concrete. In particular, the distribution of shear stresses under traffic loading and how they affect the interlayer bonding will be studied.