Steel plate-stiffener systems are widely used in civil engineering applications especially for offshore and onshore oil and gas production facilities as blast walls and blast resistant steel modular structures, and in naval and aerospace engineering applications. Such structures are typically designed based on effective breadth width concept, which enables designer to estimate behaviour of the structure by use of simple beam theory. Although, most of design guidelines for breadth width are based on several idealized steel plate behaviour, the actual behaviour of steel plate is much more complex due to nonlinear 3D stress distribution and stress transfer between the stiffeners and plate. In this study, three prototype blast wall structures were designed with varying plate thickness and stiffener properties. The walls nonlinear behaviour including force-deflection and longitudinal stress distribution through plate thickness and along plate width were investigated under out-of-plane static loading. The longitudinal stress distribution at different stress levels (i.e., elastic and several plastic levels) was used to determine effective breadth width. In addition, computed force-deflection curves of walls and corresponding simple beams with different breadth widths were compared to verify computed breadth widths. The outcomes of this study indicate that computation of effective breadth width is much more complex and highly depends on stress levels and relative stiffness of plate and stiffeners.

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The purpose of this study is to examine the vibration characteristics of a rotating blade whose material distribution varies in the spanwise direction. Formulations for functionally graded materials and beam structural models are carried out in detail and the results are displayed in several figures and tables which is a significant source of information for the authors working in this area. Different parameters such as angular speed, radius of the hub, material properties, power law index parameter, boundary conditions and slenderness ratio are considered in the formulation. Finite Element Method where the element matrices are obtained from potential and kinetic energy expressions is applied as the solution procedure. Results of the study are validated with open literature in several tables and figures.

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