Influence of anisotropy on creep in functionally graded variable thickness rotating disc

2021 ◽  
pp. 030932472199997
Author(s):  
Kishore Khanna ◽  
Vinay Kumar Gupta ◽  
Neeraj Grover
Keyword(s):  
Axial Direction ◽  
Functionally Graded ◽  
Strain Rates ◽  
Lower Yield ◽  
Rotating Disc ◽  
Creep Response ◽  
Varying Thickness ◽  
Disc Material ◽  
Lower Yield Strength ◽  
Tangential Directions

The study is carried out to develop a mathematical model to analyze creep response of a varying thickness rotating disc made of anisotropic functionally graded 6061Al-SiCw.composite. The thickness and content of reinforcement (SiCw) in the disc are assumed to decrease radially according to power law. The yielding of disc material is according to Hill’s criterion and creeping as per threshold stress based law. The developed model is used to obtain the creep stresses and strain rates in the disc for various types of materials’ anisotropy. The stresses and strain rates are noticed to depend on the materials’ anisotropy. The study reveals that the presence of kind of anisotropy wherein the disc material exhibits lower yield strength toward the radial and tangential directions than the axial direction is beneficial in reducing the creep stresses and creep rates in the disc, in comparison to isotropic FGM disc. An anisotropic FG disc, which has highest and the lowest yield strengths, respectively, along the axial and radial directions shows superior creep response.

scholarly journals Creep Response of Rotating Composite Discs having Exponential Hyperbolic Linear and Constant Thickness Profiles

2020 ◽  
Vol 70 (3) ◽  
pp. 292-298
Author(s):  
Rajinder Singh ◽  
Ravindra K. Saxena ◽  
Kishore Khanna ◽  
V. K. Gupta
Keyword(s):  
Variable Thickness ◽  
Creep Behaviour ◽  
Steady State Creep ◽  
Constant Thickness ◽  
Strain Rates ◽  
Creep Response ◽  
Thickness Profile ◽  
Disc Material ◽  
Tresca Criterion ◽  
Different Thickness

The study compares the steady state creep response of rotating Al-SiC discs having constant, linear, hyperbolic and exponential thickness with different thickness profiles. All the discs are assumed to have equal volume with the same average thickness. The creep behaviour of the disc material is described by threshold stress based law while the yielding is assumed to follow Tresca criterion. The variable thickness disc is observed to have superior creep response, expressed in terms of stresses and strain rates, to a constant thickness disc. Amongst variable thickness discs, the creep response is observed to be superior for linear thickness disc, when the inner thickness of all the discs is kept the same. However, for the same outer thickness, the disc having hyperbolic thickness profile exhibits the best creep response.

Effect of Disc Geometry on the Steady State Creep in a Rotating Disc Made of Functionally Graded Materials

2012 ◽  
Vol 736 ◽  
pp. 183-191 ◽  
Author(s):  
Manish Garg ◽  
B.S. Salaria ◽  
V.K. Gupta
Keyword(s):  
Steady State ◽  
Creep Behaviour ◽  
Pure Aluminum ◽  
Functionally Graded ◽  
Steady State Creep ◽  
Strain Rates ◽  
Rotating Disc ◽  
Graded Materials ◽  
Functionally Graded Composite ◽  
Silicon Carbide Particles

The steady state creep behaviour of a rotating FGM disc having linearly varying thickness has been investigated. The disc is assumed to be made of functionally graded composite containing non-linearly varying radial distribution of silicon carbide particles in a matrix of pure aluminum. The creep behaviour of the composite has been described by threshold stress based law. The effect of varying the disc thickness gradient has been analyzed on the stresses and strain rates in the FGM disc. It is observed that the radial and tangential stresses induced in the FGM disc decrease throughout with the increase in thickness gradient of the disc. The strain rates also decrease with the increase in thickness gradient of the FGM disc, with a relatively higher decrease near the inner radius. The increase in disc thickness gradient results in relatively uniform distribution of strain rates and hence reduces the chances of distortion in the disc.

Modelling Creep Response of a Functionally Graded Rotating Disc with Exponential Reinforcement Gradient

2019 ◽  
Vol 18 ◽  
pp. 3891-3899
Author(s):  
Rajinder Singh ◽  
R.K. Saxena ◽  
Kishore Khanna ◽  
V.K. Gupta
Keyword(s):  
Functionally Graded ◽  
Rotating Disc ◽  
Creep Response

Effect of anisotropy on creep behavior in a functionally graded material disc of variable thickness

2014 ◽  
Vol 03 (03) ◽  
pp. 1450017 ◽  
Author(s):  
Vandana Gupta ◽  
S. B. Singh
Keyword(s):  
Steady State ◽  
Creep Behavior ◽  
Functionally Graded Material ◽  
Radial Distance ◽  
Outer Radius ◽  
Functionally Graded ◽  
Steady State Creep ◽  
Rotating Disc ◽  
Creep Response ◽  
Graded Material

In this paper, an effort has been made to study the effect of anisotropy on the steady state creep behavior in the functionally graded material disc with hyperbolic thickness made of Al - SiC (particle). The content of silicon carbide particles in the disc is assumed to decrease linearly from the inner to the outer radius of the disc. The creep behavior of the disc under stresses developing due to rotation at 15,000 rpm has been determined by Sherby's law. The creep parameters of the FGM disc vary along the radial distance due to varying composition and this variation has been estimated by regression fit of the available experimental data. The creep response of rotating disc is expressed by a threshold stress with value of stress exponent as 8. The study reveals that the anisotropy has a significant effect on the steady state creep response of rotating FGM disc. Thus, the care to introduce anisotropy should be taken for the safe design of the rotating FGM disc with hyperbolic thickness.

Exact solution for free vibration analysis of linearly varying thickness FGM plate using Galerkin-Vlasov’s method

2020 ◽  
pp. 146442072098049
Author(s):  
V Kumar ◽  
SJ Singh ◽  
VH Saran ◽  
SP Harsha
Keyword(s):  
Free Vibration ◽  
Variable Thickness ◽  
Vibration Analysis ◽  
Shear Deformation Theory ◽  
Free Vibration Analysis ◽  
Functionally Graded ◽  
Constant Thickness ◽  
Engineering Structures ◽  
Property Variation ◽  
Varying Thickness

The present paper investigates the free vibration analysis for functionally graded material plates of linearly varying thickness. A non-polynomial higher order shear deformation theory is used, which is based on inverse hyperbolic shape function for the tapered FGM plate. Three different types of material gradation laws, specifically: a power (P-FGM), exponential (E-FGM), and sigmoid law (S-FGM) are used to calculate the property variation in the thickness direction of FGM plate. The variational principle has been applied to derive the governing differential equation for the plates. Non-dimensional frequencies have been evaluated by considering the semi-analytical approach viz. Galerkin-Vlasov’s method. The accuracy of the preceding formulation has been validated through numerical examples consisting of constant thickness and tapered (variable thickness) plates. The findings obtained by this method are found to be in close agreement with the published results. Parametric studies are then explored for different geometric parameters like taper ratio and boundary conditions. It is deduced that the frequency parameter is maximum for S-FGM tapered plate as compared to E- and P-FGM tapered plate. Consequently, it is concluded that the S-FGM tapered plate is suitable for those engineering structures that are subjected to huge excitations to avoid resonance conditions. In addition, it is found that the taper ratio is significantly affected by the type of constraints on the edges of the tapered FGM plate. Some novel results for FGM plate with variable thickness are also computed that can be used as benchmark results for future reference.

An Investigation of Adaptive Rubber Bearings

2016 ◽  
Author(s):  
C. S. Tsai ◽  
Hui-Chen Su ◽  
Wen-Chun Huang
Keyword(s):  
Yield Strength ◽  
Lower Yield ◽  
Passive Devices ◽  
Major Benefit ◽  
Lead Rubber Bearings ◽  
Lower Yield Strength ◽  
Multiple Levels ◽  
Materials Used ◽  
Rubber Bearings ◽  
Stiffness And Damping

Proposed in this study are several innovative seismic isolators composed of rubber materials that are called adaptive rubber bearings based on their adaptive characteristics. The materials used in the proposed isolators are free of lead commonly found in lead rubber bearings. The lead material results in a heavy environmental burden as well as lower yield strength and damping due to rising temperature during earthquakes, and thus causes larger displacements than we would expect. The designed mechanisms in the proposed isolators enable these devices to be manufactured relatively easily. They also provide extremely high damping to bearings, which is strongly desired by engineers in practice. The proposed rubber bearings are completely passive devices yet possess adaptive stiffness and adaptive high damping. The change in stiffness and damping is predictable and can be calculated at specifiable and controllable displacement amplitudes. The major benefit of the adaptive characteristics of seismic isolators is that a given system can be optimized separately for multiple performance objects at multiple levels of earthquakes. In this study, mathematical formulations are derived to explain the mechanisms of the proposed devices. Experimental results of high velocity cyclical loadings are also provided to verify the advanced concepts of the proposed devices.

Stress and deformation analysis of functionally graded varying thickness profile orthotropic rotating disk

2020 ◽  
Vol 33 ◽  
pp. 5455-5460
Author(s):  
Lakshman Sondhi ◽  
Amit Kumar Thawait ◽  
Subhashis Sanyal ◽  
Shubhankar Bhowmick
Keyword(s):  
Rotating Disk ◽  
Functionally Graded ◽  
Deformation Analysis ◽  
Thickness Profile ◽  
Varying Thickness ◽  
Stress And Deformation

Mechanical Properties and Morphologies of PP/Co-PP/Talc Composites for Microwave Application

2012 ◽  
Vol 626 ◽  
pp. 711-715 ◽  
Author(s):  
J. Piwsawang ◽  
T. Jinkarn ◽  
Chiravoot Pechyen
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Filler Loading ◽  
Lower Yield ◽  
Elongation At Break ◽  
Compression Load ◽  
Microwave Application ◽  
Lower Yield Strength ◽  
Morphology Development ◽  
Internal Mixer

Unmodified talc fillers were compounded with polypropylene (PP) and copolymer polyethylene (Co-PP) separately in a Brabender plasticorder internal mixer at 180 °C and 50 rpm in order to obtain composites, which contain 040 phr (per 100 part of resin) of filler at 40 phr intervals. The morphology development and the mechanical properties of the composites with reference to filler loading were investigated. In terms of mechanical properties, Youngs modulus and maximum compression load increased, whereas yield strength and elongation at break decreased with the increase in filler loading of PP/Co-PP/Talc composites. The PP/Co-PP exhibited lower yield strength and youngs modulus, and higher elongation at break than talc composites (data not show here). Scanning electron microscopy (SEM) was used to examine the structure of the fracture surface to justify the variation of the measured mechanical properties.

Characteristic of Interface Crack Propagation in Dissimilar Weld Joints

2014 ◽  
Vol 988 ◽  
pp. 249-252 ◽  
Author(s):  
Wei Bing Wang ◽  
He Xue ◽  
Fu Qiang Yang ◽  
Xu Sheng Zhou
Keyword(s):  
Interface Crack ◽  
Propagation Characteristic ◽  
Extended Finite Element ◽  
Lower Yield ◽  
Mechanical Heterogeneity ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
Propagation Behavior ◽  
Lower Yield Strength ◽  
Ductile Fracture Model

The propagation behavior of crack with different initiation position is affected by the constraint effect differences in dissimilar weld joints mechanical heterogeneity. The ductile fracture model of interface crack in dissimilar weld joints was built by adopting extended finite element method; the propagation characteristic of interface crack was summarized. The results indicate that the strength mismatch of materials at sides of interface will increase trend of crack advancing into the relative soft material which has lower yield strength and lower hardening exponent.

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