Exploratory Advanced Research . . . Next Generation Transportation Solutions

Predicting Materials Behavior 

Advancing Multiscale Modeling Techniques

on one continuum, for example bridging 

quantum mechanics (QM) and reaction force 

field (ReaxFF) theory (describing the forces 

within and between individual atoms) to 

molecular dynamics; however, to understand 

and predict material behavior at all scales, the 

continuum must be addressed through quantum, 

molecular, and microscale models. This research 

aims to eliminate the limitations of current 

techniques by integrating a digital specimen and 

digital test technique that makes use of 

multiscale microstructure characterization, 

obtained using multiscale computerized 

tomography (CT) imaging. 

Technical Approach

The study explores the use of both chemical and 

mechanical energy, and the combination of 

mechanical and electrical engineering. The goal 

is to develop a generalized multiscale modeling 

theory and generate computational algorithms 

and software for implementing the theory. 

Initially, a generalized multiscale dynamical 

field theory will be developed, to be followed 

by an integrated thermomechanical and 

electromagnetic theory. Corresponding 

computational algorithms & computer software 

will also be developed to enable the numerical 

implementation of these theories and the 

applicability of the theories and algorithms will 

be demonstrated in structural material 

development, including analysis under extreme 

environmental conditions. 

The digital specimen and testing technique 

will be utilized as a platform to bridge different 

scale and structure simulations and ultimately 

solve mesoscale problems. Multiscale CT 

technology will be used to image sections of the 

material structure from nanometer to millimeter, 

and an ion beam will be used to cut specimens 

so that the mechanical properties of materials at 

nano- and microscale can be characterized. The 

most recent update of the ReaxFF theory will be 

utilized and other techniques will also be 

implemented, including the use of molecular 

dynamics and joint statistical mechanics to 

apply mathematical tools and theories to study 

and develop rules for behavior. 

The theory and programs will be 

demonstrated in three specific situations: 

The Exploratory Advanced Research Program Fact Sheet

Modeling Techniques

Current material evaluation is conducted using 

macroscale models and a set of specific failure 

criteria to assess behavior. As a result, some 

types of failure are well understood and 

predicted at the macroscale level, for example 

in cases of visible cracking where there are 

mechanical forces that lead to the separation 

of materials. Other types of failure mechanisms 

are more complex and require understanding 

of materials properties across the continuum of 

engineering scales, from the nano to the macro.

Although nanoscale properties are recognized 

as important controlling factors in this cracking 

behavior, existing mechanical and structural 

models are not yet able to accurately predict 

phenomena at the nanoscale, or their 

implications for materials behavior in the field. 

Mixing different components can often result 

in complex and unpredictable physical 

interactions, chemical reactions, and 

electromagnetic reactions. These forces can lead 

to a weakened molecular structure and 

reduced bonding between materials, resulting 

in early deformation but with no signs of 

visible separation or cracking. 

Modeling Limitations

Current multiscale modeling techniques focus 

Mix design methods for infrastructure 

materials used to be highly empirical and 

depend on representative tests and traditional 

modeling techniques to evaluate properties and 

assess behavior; however, due to scaling effects 

and environmental and structural differences 

between the laboratory and field, these methods 

may not accurately predict material performance. 

“Mechanical and Structural Nanoscale Modeling” 

is a Federal Highway Administration (FHWA) 

Exploratory Advanced Research (EAR) Program 

study in partnership with Virginia Polytechnic 

Institute and State University, aimed at improving 

multiscale modeling techniques. 
(1) cement hydration—an important factor for the 

curing of cementitious materials; (2) impact 

damage—to measure the dynamical properties 

of concrete at high strain rate; (3) a sensormonitoring application—to monitor the structural 

response of a bridge to traffic and provide 

structural health data for estimating cumulative 

fatigue damage. The results will be utilized to 

examine the following areas:

•	 How ReaxFF theory enhances mix design and 

understanding of material behavior.

•	 How multiscale modeling enhances accuracy in 

predicting material deformation and failure.

•	 How multiscale testing of specimens reduces 

the effort required versus traditional modeling 

techniques.

•	 How multiscale modeling techniques provides 

educational value.

•	 How these techniques could be integrated in 

the future multiscale infrastructure.

Challenges and Benefits

There are some significant challenges to overcome, 

specifically verifying the bridging scales methods 

and addressing computing power limitations. The 

multiscale modeling techniques are ultimately 

expected to have significant impact on guiding 

material mix design for desired properties. The 

study is expected to minimize demand for 

mechanical testing, especially testing at nanoscale 

and under extreme conditions, and enhance the 

accuracy of predicting structural failures. The 

development of prototype computer software will 

also enable integration of several modules capable 

of performing multiscale modeling of realistic 

structure or materials problems. 

Moving Forward

If successful, the results will minimize the demand 

for empirical testing in research and material 

development and enhance the accuracy of 

predicting structural failures. The findings of this 

study may lead to significantly reduced costs 

for testing and evaluation of material and the 

design of mixes with high-performance and 

multifunctional properties. Additionally, the 

multiscale modeling software could eventually 

be adopted as an exploration tool for predicting 

structural and material behavior under complicated 

environmental conditions.

What Is the Exploratory 

Advanced Research Program?

FHWA’s Exploratory Advanced Research 

(EAR) Program focuses on long-term, 

high-risk research with a high payoff 

potential. The program addresses underlying 

gaps faced by applied highway research 

programs, anticipates emerging issues with 

national implications, and reflects broad 

transportation industry goals and objectives. 

To learn more about the EAR Program, 

visit the Exploratory Advanced Research Web 

site at www.fhwa.dot.gov/advancedresearch. 

The site features information on research 

solicitations, updates on ongoing research, 

links to published materials, summaries of 

past EAR Program events, and details on 

upcoming events. For more information, 

contact David Kuehn at FHWA, 202-493-

3414 (david.kuehn@dot.gov), or contact 

Terry Halkyard at FHWA, 202-493-3467 

(terry.halkyard@dot.gov).

Predicting Materials Behavior 

Advancing Multiscale Modeling Techniques

Publication No. 

FHWA-HRT-12-070

HRTM-30/10-12(1M)E

Learn More

For more information on this EAR Program 

project, contact Kunik Lee, Ph.D., FHWA Office 

of Safety Research and Development, at 202-

493-3491 (email: kunik.lee@dot.gov).

Photo credit, page 1: 

© iStockphoto/

kevinjeon00

Photo credit, page 2: 

Andres Jaramillo-Botero, 

Lianchi Liu and 

William A. Goddard III

ReaxFF predicted molecular geometry for a partial Ettringite 

crystal is in close agreement with QM data (Al-Al distance 

and Ca-O-Al angle example shown here).