Developments of Computational Mechanics Theories and Technologies
The success of establishing computational predictive capabilities is based not only upon developing predictive computational models, but also providing robust and efficient computational infrastructure; i.e., a proper computational simulator. For example, to address modern computational multiscale and multiphysics problems, the nature of the problem requires flexibility and adaptivity of the numerical method. To properly address this issue, we have developed a strong form collocation method, a particle difference method, as a new generation of solution method that can circumvent these difficulties. A prototype of massively-parallelized particle difference method code has been developed, and successfully demonstrated its capability and accuracy for various engineering problems.
Computational Multiscale/Multiphysics Analysis for Materials Design
Multiscale and multiphysics analysis is useful for the mechanical study of various structural materials, ranging from conventional steels and alloys to new advanced materials, such as carbon-fiber reinforced polymer composites, advanced nano engineered aluminum alloys, and nano fiber reinforced concrete materials. This research can also play an important role in structural failure analysis, because the failure of the basic constituents of any material has the potential to lead to the failure of the overall structure. Through this research, we try to gain a fundamental understanding of material behaviors, including their deterioration processes, i.e. failure. A better understanding of the failure mechanisms of materials will be the first step towards more accurate predictions of the failure strength of existing structures, and will eventually lead us to better designs for future structures by replacing classical design criteria; of course, this research can also be useful for designing and characterizing new structural materials.
Computational Analysis for Complex Structural Interaction System
Computational modeling such as fluid-structure or multi-structural-system interaction systems is essential for dealing with multi-physical phenomena in nature, as well as an important class of engineering problems that has recently come to the forefront in structural engineering mechanics. The modeling of offshore structures, bridge/building-wind interactions, and wave-energy converters are good examples of these problems. Comprehension of these complex systems comes from an understanding of not only the independent behaviors of constituent elements, but the interactive behavior of all the elements that constitute the system. However, because of the multidisciplinary nature and complexity of modeling interaction system, the current computational approaches are limited. We  are currently working on these problems to further investigate and develop multi-physics-based computational analysis frameworks that can allow us to predict a wide range of environmental or loading scenarios that may cause a risk to civil infrastructure systems.
Computational Failure Analysis for Predicting Residual Strength
Computational failure analysis is a very important research topic in structural engineering since it can provide structural safety criteria, not only for predicting failure risks of current structures but also for designing less vulnerable structures in the future. A primary goal of this research is to determine whether a structure is capable of performing its originally intended functions over an expected service time with an acceptable risk of failure. Through this research, we try to precisely delineate weak spots that may cause the catastrophic failure of structures (or designs), and provide appropriate guidelines for retrofitting current structures (or strengthening future designs).