scholarly journals Free Vibration Investigations of Rotating FG Beams Resting on Elastic Foundation with Initial Geometrical Imperfection in Thermal Environments

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Dang Nguyen Van
Keyword(s):  
Free Vibration ◽  
Turbine Blades ◽  
Shear Deformation Theory ◽  
Effect Of Temperature ◽  
Railway Bridges ◽  
Gas Turbine Blades ◽  
Thermal Environments ◽  
Marine Engines ◽  
Geometrical Imperfections ◽  
Sine Functions

In practical operations of mechanical structures, it is not difficult to meet some large components such as helicopter rotors, gas turbine blades of marine engines, and rotating railway bridges, where these elements can be seen as beam models rotating around one fixed axis. Therefore, mechanical explorations of these structures with and without the effect of temperature will guide the design, manufacture, and use of them in practice. This is the first paper that uses the shear deformation theory-type hyperbolic sine functions and the finite element method to analyze the free vibration response of rotating FGM beams with initial geometrical imperfections resting on elastic foundations considering the effect of temperature. The material properties are assumed to be varied in the thickness direction of the beam based on the power law function and temperature changes The proposed theory and mathematical model are verified by comparing the results with other exact solutions. The numerical investigations have taken into account some geometrical and material parameters to evaluate the effects on the vibration behavior of the structure such as the rotational speed, temperature, as well as initial geometrical imperfections. The drawn comments have numerous scientific and practical implications for rotating beam structures.

scholarly journals A Third-Order Shear Deformation Theory for Bending Behaviors of Rotating FGM Beams Resting on Elastic Foundation with Geometrical Imperfections in Thermal Environments

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Nguyen Van Dang
Keyword(s):  
Shear Deformation ◽  
Material Properties ◽  
Deformation Theory ◽  
Turbine Blades ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Engineering Practice ◽  
Thermal Environments ◽  
Graded Material ◽  
Geometrical Imperfections

Beam-shaped components in large mechanical structures such as propellers, gas turbine blades, engine turbines, rotating railway bridges, and so on, when operating, usually engage in rotational movement around the fixed axis. Studying the mechanical behavior of these structures has great significance in engineering practice. Therefore, this paper is the first investigation on the static bending of rotating functionally graded material (FGM) beams with initial geometrical imperfections in thermal environments, where the higher-order shear deformation theory and the finite element method (FEM) are exercised. The material properties of beams are assumed to be varied only in the thickness direction and changed by the temperature effect, which increases the correctness and proximity to technical reality. The numerical results of this work are compared with those of other published papers to evaluate the accuracy of the proposed theory and mechanical model used in this paper. A series of parameter studies is carried out such as geometrical and material properties, especially the rotational speed and temperature, to evaluate their influences on the bending responses of structures.

FREE VIBRATION AND BUCKLING OF FUNCTIONALLY GRADED SHELL PANELS IN THERMAL ENVIRONMENTS

2010 ◽  
Vol 10 (05) ◽  
pp. 1031-1053 ◽  
Author(s):  
S. PRADYUMNA ◽  
J. N. BANDYOPADHYAY
Keyword(s):  
Free Vibration ◽  
Compressive Load ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Power Law Distribution ◽  
Temperature Dependent ◽  
Graded Materials ◽  
Thermal Environments ◽  
Buckling Behavior ◽  
Doubly Curved

This paper investigates the free vibration and buckling behavior of singly and doubly curved shell panels made of functionally graded materials (FGMs). A higher-order shear deformation theory is used for the analysis of five shell panels, namely, cylindrical (CYL), spherical (SPH), hyperbolic paraboloid (HPR), hypar (HYP), and conoid (CON). The shell panels are subjected to a temperature field and in the case of buckling analysis, the shell panels are also subjected to a uniaxial compressive load. The properties of FGMs are considered to be temperature dependent and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. The accuracy of the formulation is validated by comparing the results with those available in the literature. The effects of geometric properties, material composition, and boundary conditions on the free vibration and buckling are studied.

scholarly journals Free vibration analysis of functionally graded shell panels with various geometric shapes in thermal environment

2018 ◽  
Vol 40 (3) ◽  
pp. 199-215
Author(s):  
Duong Thanh Huan ◽  
Tran Huu Quoc ◽  
Tran Minh Tu
Keyword(s):  
Free Vibration ◽  
Vibration Analysis ◽  
Thermal Environment ◽  
Free Vibration Analysis ◽  
Middle Surface ◽  
Functionally Graded ◽  
Effect Of Temperature ◽  
Shell Elements ◽  
Geometric Shapes ◽  
Thermal Environments

This paper presents free vibration analysis of functionally graded materials (FGMs) shell panels with various geometric shapes in thermal environments. The shell panels are made from a mixture of metal and ceramic. Material properties are assumed to be temperature-dependent and graded in the thickness direction according to a power law function. A formulation of eight-nodded middle surface shell elements based on Reissner-Mindlin assumptions is developed for modeling FGM shell panels under the effect of temperature, which changes nonlinearly across the thickness. Numerical results obtained by the proposed model are in good agreement with those available in the literature. The effects of geometric properties, material composition, boundary conditions and temperature on the natural frequencies are investigated.

Chemical partitioning of elements in Ni-base MC-carbide reinforced eutetic superalloys

1983 ◽  
Vol 41 ◽  
pp. 250-251
Author(s):  
E. F. Koch ◽  
E. L. Hall ◽  
S. W. Yang
Keyword(s):  
Alloy Composition ◽  
Volume Fraction ◽  
Lattice Mismatch ◽  
Turbine Blades ◽  
Eutectic Alloys ◽  
Alloy Matrix ◽  
X Ray ◽  
Gas Turbine Blades ◽  
Analytical Electron ◽  
Analytical Electron Microscope

The plane-front solidified eutectic alloys consisting of aligned tantalum monocarbide fibers in a nickel alloy matrix are currently under consideration for future aircraft and gas turbine blades. The MC fibers provide exceptional strength at high temperatures. In these alloys, the Ni matrix is strengthened by the precipitation of the coherent γ' phase (ordered L12 structure, nominally Ni3Al). The mechanical strength of these materials can be sensitively affected by overall alloy composition, and these strength variations can be due to several factors, including changes in solid solution strength of the γ matrix, changes in they γ' size or morphology, changes in the γ-γ' lattice mismatch or interfacial energy, or changes in the MC morphology, volume fraction, thermal stability, and stoichiometry. In order to differentiate between these various mechanisms, it is necessary to determine the partitioning of elemental additions between the γ,γ', and MC phases. This paper describes the results of such a study using energy dispersive X-ray spectroscopy in the analytical electron microscope.

Using phase field and third-order shear deformation theory to study the effect of cracks on free vibration of rectangular plates with varying thickness

2020 ◽  
Vol 71 (7) ◽  
pp. 853-867
Author(s):  
Phuc Pham Minh
Keyword(s):  
Free Vibration ◽  
Shear Deformation ◽  
Phase Field ◽  
Deformation Theory ◽  
Plate Thickness ◽  
Shear Deformation Theory ◽  
Rectangular Plates ◽  
Equilibrium Equations ◽  
Third Order ◽  
Free Vibration Frequency

The paper researches the free vibration of a rectangular plate with one or more cracks. The plate thickness varies along the x-axis with linear rules. Using Shi's third-order shear deformation theory and phase field theory to set up the equilibrium equations, which are solved by finite element methods. The frequency of free vibration plates is calculated and compared with the published articles, the agreement between the results is good. Then, the paper will examine the free vibration frequency of plate depending on the change of the plate thickness ratio, the length of cracks, the number of cracks, the location of cracks and different boundary conditions

UDIMET L-605

Alloy Digest ◽  
2004 ◽  
Vol 53 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Gas Turbine ◽  
Oxidation Resistance ◽  
Turbine Blades ◽  
Heat Treating ◽  
Gas Turbine Blades ◽  
Temperature Performance

Abstract Udimet L-605 is a high-temperature aerospace alloy with excellent strength and oxidation resistance. It is used in applications such as gas turbine blades and combustion area parts. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: CO-109. Producer or source: Special Metals Corporation.

scholarly journals Forced Vibration Analysis of Laminated Composite Shells Reinforced with Graphene Nanoplatelets Using Finite Element Method

2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Trung Thanh Tran ◽  
Van Ke Tran ◽  
Pham Binh Le ◽  
Van Minh Phung ◽  
Van Thom Do ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Forced Vibration ◽  
Vibration Analysis ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Thermal Environments ◽  
Forced Vibration Analysis ◽  
Laminated Composite Shells ◽  
Element Method

This paper carries out forced vibration analysis of graphene nanoplatelet-reinforced composite laminated shells in thermal environments by employing the finite element method (FEM). Material properties including elastic modulus, specific gravity, and Poisson’s ratio are determined according to the Halpin–Tsai model. The first-order shear deformation theory (FSDT), which is based on the 8-node isoparametric element to establish the oscillation equation of shell structure, is employed in this work. We then code the computing program in the MATLAB application and examine the verification of convergence rate and reliability of the program by comparing the data of present work with those of other exact solutions. The effects of both geometric parameters and mechanical properties of materials on the forced vibration of the structure are investigated.

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