Efficient optimal frequency design of elastically supported distributed-parameter cantilevers
✍ Scribed by I. Takewaki
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 897 KB
- Volume
- 62
- Category
- Article
- ISSN
- 0045-7949
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✦ Synopsis
The purpose of this paper is to develop an efficient numerical method for finding the optimal bending stiffness distribution of an elastically supported distributed-parameter cantilever under a fundamental natural frequency constraint. The distributed-parameter cantilever is modeled by an FEM system and the bending stiffness distribution is approximated by a piecewise-linear function. A cubic displacement function is utilized in the FEM system. It is shown that a semi-explicit expression, due to the present author, of the optimal bending stiffness distribution for a fixed-base model plays the key role in developing the efficient numerical method for an elastically supported model. A difficulty of solving nonlinear equations resulting from the effect of structural masses is overcome by combining the semi-explicit optimal design formula for a fixed-base mode1 with a recursive technique for evaluating foundation displacements and solution stiffnesses. A numerical example of an elastically supported tower structure is presented in order to demonstrate the validity, efficiency and accuracy of this method.