• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.4
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• pp.645-653
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• 2001

It is well known that natural frequencies increase when a cantilever beam rotates about the axis perpendicular to its longitudinal axis. Such phenomena that are caused by centrifugal inertia forces are often referred to as the stiffening effects. Occasionally it is necessary to control the variation of a natural frequency or the maximum stress of a rotating beam. By changing the thickness of the rotating beam, the modal or the stress characteristics can be changed. The thickness of the rotating beam is assumed to be a cubic spline function in the present work. An optimization method is employed to find the optimal thickness shape of the rotating beam. This method can be utilized for the design of rotating structures such as turbine blades and aircraft rotary wings.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.643-648
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• 2000

It is well known that natural frequencies increase when a cantilever beam rotates about the axis perpendicular to its longitudinal axis. Such phenomena that are caused by centrifugal inertia forces are often referred to as the stiffening effects. Occasionally it is necessary to control the variation of a natural frequency of a rotating beam. By changing the thickness of the rotating beam, the modal characteristics can be changed. The thickness of the rotating beam is assumed to be a cubic spline function in the present work. An optimization method is employed to find the optimal thickness shape of the rotating beam. This method can be utilized usefully for the design of rotating structures such as turbine blades and aircraft rotary wings.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.746-751
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• 2003

When a cantilever beam rotates about the axis perpendicular to its longitudinal axis, its natural frequencies vary. This phenomenon which is caused by centrifugal inertia forces is often referred to as the stiffening effects. Since the variation of natural frequencies often creates critical problems for the rotating structures, it is necessary to control the variation of natural frequencies. As the cross section of a rotating cantilever beam varies, natural frequencies can be changed. The thickness and the width of the cantilever beam are assumed to be cubic spline functions in the present work. An optimization method is employed to find the optimal thickness and width of the rotating beam. This result can be used for the design of rotating structures such as turbine and helicopter blades.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.6
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• pp.477-485
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• 2012

Geometric configurations such as hull shape, wall thickness, stiffener layout, and type of construction materials are the key factors influencing the structural performance of pressure hulls. Traditional theoretical approach provides quick and acceptable solutions for the design of pressure hulls within specific geometric configuration and material. In this paper, alternative approaches that can be used to obtain optimal geometric shape, wall thickness, construction material configuration and stiffener layout of a pressure hull are presented. CAE(Computer Aided Engineering) based design optimization tools are utilized in order to obtain the required structural responses and optimal design parameters. Optimal elliptical meridional profile is determined for a cylindrical pressure hull design using metamodel-based optimization technique implemented in a fully-integrated parametric modeler-CAE platform in ANSYS. While the optimal composite laminate layup and the design of ring stiffener for a thin-walled pressure hull are obtained using gradient-based optimization method in OptiStruct. It is noted that the proposed alternative approaches are potentially effective for pressure hull design.