Analysis of forced and free vibrations of composite porous core sandwich cylindrical shells and FG-CNTs reinforced face
- PDF / 1,801,236 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 69 Downloads / 220 Views
(2020) 42:504
TECHNICAL PAPER
Analysis of forced and free vibrations of composite porous core sandwich cylindrical shells and FG‑CNTs reinforced face sheets resting on visco‑Pasternak foundation under uniform thermal field Farhad Kiani1 · Maboud Hekmatifar2 · Davood Toghraie2 Received: 3 February 2020 / Accepted: 25 August 2020 © The Brazilian Society of Mechanical Sciences and Engineering 2020
Abstract The radial basis function and Newmark-beta methods were used to investigate the vibrational behavior of composite sandwich cylindrical shells with porous core and functionally graded carbon nanotube. The porous core material is a kind of open-cell metal foam, whose, depending on the porosity coefficient and the core thickness, mechanical properties vary. The Hamilton principle was used to extract its motion equations. In this cylindrical sandwich shell, temperature variations are uniformly distributed and resting on the visco-Pasternak foundation with different boundary conditions. Parametric studies were presented to investigate the influence of FG porosity, temperature change, visco-Pasternak foundation, volume fraction, geometrical properties, and distribution of carbon nanotubes on natural frequencies and response dynamics of the sandwich composite cylindrical shell. The numerical outcomes express the distribution of CNTs and volume fraction play a pivotal role in the natural rates and dynamic response of the cylindrical sandwich shell. It is also perceived that there is an increase in the cylindrical shell deformation amplitude with an increase in temperature, damping, and core porosity. Keywords Sandwich · Cylindrical shell · Porous core · FG-CNTs · Thermal field · Visco-Pasternak
1 Introduction The use of carbon nanotubes instead of traditional fibers has many advantages, such as increasing the strength, stiffness, and resistance of composites. The increasing trend to utilize fiber reinforced composites for lightweight, high-performance applications has inspired researchers to study structures with metal foam and reinforcement using carbon nanotubes [1–4]. Given the fact that carbon nanotubes have very high mechanical properties, they can be used as reinforcement for porous environments. With the development of high-strength and lightweight structural elements, an exciting field of new applications has emerged from these coupled features. Adding single-wire carbon Technical Editor: José Roberto de França Arruda. * Davood Toghraie [email protected] 1
Department of Mechanical Engineering, Shahinshahr Branch, Islamic Azad University, Shahinshahr, Iran
Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr, Iran
2
nanotube (SWCNT) to industrial epoxy, [5] improved its thermal properties. The addition of one percent carbon nanotube increased the thermal conductivity to 125% at 25° C. Research shows that by adding a small number of carbon nanotubes (2–5%) to the composite material, mechanical properties such as stiffness and strength increase significa
Data Loading...
