Gary F. Dargush

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Due to the complexity of acute care facilities, and depending on the extent of seismic deficiencies in any specific hospital, considerable investment may be required to ensure that an acute care facility remains operational following an earthquake. The extensive resources that would be required to achieve such a level of resilience would likely not be(More)
The paper begins with an overview of several of the classical integral formulations of elastodynamics, which highlights the natural appearance of temporal convolutions in the reciprocal theorem for such problems. This leads first to the formulation of a principle of virtual convolved action, as an extension of the principle of virtual work to dynamical(More)
The objective of this study is to develop a new constitutive model for cyclic response of metals with much broader applicability. Accordingly, a two-surface damage thermoplasticity model is proposed to understand inelastic behavior and to evaluate a potential damaged state of the metals. This model, which derived from small strain theory, is formulated(More)
A true variational formulation is developed for dissipative processes based upon the concept of mixed convolved action. Here the focus is on continuum problems associated with heat diffusion, as well as related second sound phenomena. The convolved action can overcome the shortcomings of typical action principles, such as Hamilton's principle, to address(More)
Although Lagrangian and Hamiltonian analytical mechanics represent perhaps the most remarkable expressions of the dynamics of a mechanical system, these approaches also come with limitations. In particular, there is inherent difficulty to represent dissipative processes and the restrictions placed on end point variations are not consistent with the(More)
We develop a variational principle based on recent advances in couple-stress theory and the introduction of an engineering mean curvature vector as energy conjugate to the couple stresses. This new variational formulation provides a base for developing a couple-stress finite element approach. By considering the total potential energy functional to be not(More)
With the conceptual development of performance-based design, the earthquake engineering community has begun to recognize the importance of controlling both interstory drifts and absolute floor accelerations. However, these often present conflicting requirements for design. In this paper, we present a multi-objective genetic algorithm to address this(More)
A Genetic Algorithm (GA) is proposed in which each member of the population can change schemata only with its neighbors according to a rule. The rule methodology and the neighborhood structure employ elements from the Cellular Automata (CA) strategies. Each member of the GA population is assigned to a cell and crossover takes place only between adjacent(More)
Over the last two decades, significant research effort has been directed toward the application of advanced technologies to improve the seismic performance of civil infrastructure. MCEER has played a role in that development. In this paper, we present an overview of the integrated MCEER research program aimed at the development of a new generation of(More)
Based on thermodynamic principles, we derive expressions quantifying the non-harmonic vibrational behavior of materials, which are rigorous yet easily evaluated from experimentally available data for the thermal expansion coefficient and the phonon density of states. These experimentally-derived quantities are valuable to benchmark first-principles(More)