![]() Although the United States power grid has maintained a high level of reliability for decades, it is rapidly running up against its limitations. While improving transport capability, the system must operate within thermal limits and system stability must be maintained each alone is necessary but not sufficient for reliable system operation. The objective of enhancing the performance is to safely and reliably transport more electrical energy through the power transmission system. (authors) « lessĪdvanced technologies to enhance performance of the nation’s electricity delivery system have been proposed over the past decade by many organizations. Furthermore, the potential for widespread damage from some of these insults requires an approach that addresses the impacts of these potentially severe insults even when they occur in locations distant from the actual physical location of a component or structure modeled in the traditional PRA. Intentional acts might produce harsh environments that in turn could subject components and structures to one or more insults, such as structural, fire, flood, and/or vibration and shock damage. Given the nature of intentional acts, extensive modifications must be made to the risk models to account for the special nature of the 'initiating events' associated with deliberate adversary actions. The use of 'damage footprints' requires that the basic events from the traditional probabilistic risk more » assessment (PRA) be spatially transformed so that the failure of individual components can be linked to the destruction of or damage to specific spatial zones within the plant. A 'damage footprint' is a spatial map of regions of the plant (zones) where equipment could be physically destroyed or disabled as a direct consequence of an intentional act. This paper describes a process by which traditional risk models can be spatially informed to analyze the effects of compound and widespread harsh environments through the use of 'damage footprints'. Traditional risk models can be adapted to evaluate plant response for situations where plant systems and structures are intentionally damaged, such as from sabotage or terrorism. Because input energy includes absorbed energy as well as relative kinetic energy and dissipated energy, it is the recommended energy quantity for assessing the severity for both random vibration and shock environments on a structure. ![]() Our work shows that the modal properties of the structure and the spectral more » content of the input must be considered together to assess damage risk. A numerical example illustrates the spatial and modal decomposition of input energy and its utility in identifying components at risk of damage in random vibration and shock environments. We show the steady state input energy can be decomposed both spatially and modally and computed using input power spectra. What is less appreciated is that input energy can be computed at the component level exactly, using the component effective modal mass. That input energy can be decoupled modally is well known. ![]() The quantity of interest is input energy. The motivation for this work is that most systems fail functionally due to component failure, not because the primary structure was overloaded, and the ability to easily compute the spatial distribution of energy helps identify failure sensitive components. The main objective of this paper is to show how to compute the energy in the components of a mechanical system. When designing or analyzing a mechanical system, energy quantities provide insight into the severity of shock and vibration environments however, the energy methods in the literature do not address localized behavior because energy quantities are usually computed for an entire structure. ![]()
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