A numerical investigation on the natural frequencies of FGM sandwich shells with variable thickness by the local generalized differential quadrature method
| Autor: | Erasmo Viola, J. N. Reddy, Nicholas Fantuzzi, Francesco Tornabene, Michele Bacciocchi |
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| Přispěvatelé: | Tornabene, Francesco, Fantuzzi, Nichola, Bacciocchi, Michele, Viola, Erasmo, Reddy, Junuthula N. |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
free vibration analysi
Degrees of freedom (statistics) Shell (structure) higher-order structural theories functionally graded material Geometry Functionally graded material 02 engineering and technology Power law lcsh:Technology Variable thickness shell local generalized differential quadrature method lcsh:Chemistry functionally graded materials free vibration analysis variable thickness shells 0203 mechanical engineering General Materials Science Free vibration analysi Instrumentation lcsh:QH301-705.5 Mathematics Fluid Flow and Transfer Processes lcsh:T Process Chemistry and Technology Applied Mathematics Isotropy Mathematical analysis General Engineering Higher-order structural theorie 021001 nanoscience & nanotechnology Finite element method lcsh:QC1-999 Computer Science Applications Quadrature (mathematics) 020303 mechanical engineering & transports Distribution (mathematics) lcsh:Biology (General) lcsh:QD1-999 lcsh:TA1-2040 Nyström method higher-order structural theorie 0210 nano-technology lcsh:Engineering (General). Civil engineering (General) lcsh:Physics |
| Zdroj: | Applied Sciences; Volume 7; Issue 2; Pages: 131 Applied Sciences, Vol 7, Iss 2, p 131 (2017) |
| Popis: | The main aim of the present paper is to solve numerically the free vibration problem of sandwich shell structures with variable thickness and made of Functionally Graded Materials (FGMs). Several Higher-order Shear Deformation Theories (HSDTs), defined by a unified formulation, are employed in the study. The FGM structures are characterized by variable mechanical properties due to the through-the-thickness variation of the volume fraction distribution of the two constituents and the arbitrary thickness profile. A four-parameter power law expression is introduced to describe the FGMs, whereas general relations are used to define the thickness variation, which can affect both the principal coordinates of the shell reference domain. A local scheme of the Generalized Differential Quadrature (GDQ) method is employed as numerical tool. The natural frequencies are obtained varying the exponent of the volume fraction distributions using higher-order theories based on a unified formulation. The structural models considered are two-dimensional and require less degrees of freedom when compared to the corresponding three-dimensional finite element (FE) models, which require a huge number of elements to describe the same geometries accurately. A comparison of the present results with the FE solutions is carried out for the isotropic cases only, whereas the numerical results available in the literature are used to prove the validity as well as accuracy of the current approach in dealing with FGM structures characterized by a variable thickness profile. |
| Databáze: | OpenAIRE |
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