986 resultados para Lot sizing


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The absence of adequate inspection data from difficult-to-access areas on pipelines, such as cased-road crossings, makes determination of fitness for continued service and compliance with increasingly stringent regulatory requirements problematic. Screening for corrosion using long-range guided wave testing is a relatively new inspection technique. The complexity of the possible modes of vibration means the technique can be difficult to implement effectively but this also means that it has great potential for both detecting and characterizing flaws. The ability to determine flaw size would enable the direct application of standard procedures for determining fitness-for-service, such as ASME B31G, RSTRENG, or equivalent for tens of metres of pipeline from a single inspection location. This paper presents a new technique for flaw sizing using guided wave inspection data. The technique has been developed using finite element models and experimentally validated on 6'' Schedule 40 steel pipe. Some basic fitness-for-service assessments have been carried out using the measured values and the maximum allowable operating pressure was accurately determined. © 2011 American Institute of Physics.

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info:eu-repo/semantics/published

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The main goal of a cell stability MHD model like MHD-Valdis is to help locate the busbars around the cell in a way which leads to the generation of a magnetic field inside the cell that itself leads to a stable cell operation. Yet as far as the cell stability is concerned, the uniformity of the current density in the metal pad is also extremely important and can only be achieved with a correct busbar network sizing. This work compares the usage of a detailed ANSYS based 3D thermo-electric model with the one of the versatile 1D part of MHD-Valdis to help design a well balanced busbar network.

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The introduction of skin sub-stiffening features has the potential to modify the local stability and fatigue crack growth performance of stiffened panels. Proposed herein is a method to enable initial static strength sizing of panels with such skin sub-stiffening features. The method uses bespoke skin buckling coefficients, automatically generated by Finite Element analysis and thus limits the modification to the conventional aerospace panel initial sizing process. The approach is demonstrated herein and validated for prismatic sub-stiffening features. Moreover, examination of the generated buckling coefficient data illustrates the influence of skin sub-stiffening on buckling behavior, with static strength increases typically corresponding to a reduction in the number of initial skin longitudinal buckle half-waves.