Nonlocal dual-phase-lagging thermoelastic damping in rectangular and circular micro/nanoplate resonators

Effect of three-phase-lag model on the analysis of three-dimensional free vibrations of viscothermoelastic solid cylinder

This paper aims to present the analysis of transient wave characteristics in a functionally graded viscothermoelastic infinite medium with spherical cavity in the context of generalized thermoelasticity Continued series solution is used to solve simultanious differential equations for evaluating the field variables Convergence of the series solution is implemented and investigated that the series of functions are absolutely and uniformly convergent The formal solution for the field variables are obtained analytically and represented graphically The effect of grading index and different theories of generalized thermoelasticity are also shown graphically to examine the behavior of the variations of the field variables

Effect of phase-lags on the transient waves in an axisymmetric functionally graded viscothermoelastic spherical cavity in radial direction

Precisely calculating quality factor based on thermoelastic damping (TED) is of great importance for the design and optimization of micro/nano-resonators. With the consideration of size-dependent effects in the thermal and mechanical fields and the non-Fourier (NF) heat conduction effect, analytical expressions of TED in the micro/nanobeam resonator are proposed by adopting the theories of the modified-couple-stress (MCS) model and the nonlocal dual-phase-lag (DPL) model. TED models expressed in the series form and the explicit form are both developed basing on the energy-definition approach. The differences among TED models are discussed. In the simulation, silicon and gold, which are two representative materials with typical intrinsic length-scale quantities and phase-lag times, are selected for illustration. Additionally, the nonlocal thermal length-scale parameter refers to the mean-free-path (MFP) of energy carriers, and the MCS mechanical length-scale parameter is not constant but proportional to the beam thickness. TED results obtained by the classical model and the previous DPL model are also shown for comparison. The peak phenomena of TED spectra including the peak damping and the peak frequency are investigated according to the present simple model. Results reveal that TED in micro/nanobeam resonators is of dependence observably on the effect of nonlocal DPL-NF heat conduction associated with the thermal field, and the quality factor is improved by the MCS mechanical size-dependent effect.

Thermoelastic damping in the size-dependent micro/nanobeam resonator with nonlocal dual-phase-lag heat conduction

Kinematics and improved surface roughness model in milling

In this article, the constitutive relations and the governing equations are derived for nonlocal thermoelastic solid in the presence of diffusion. The free vibration of a thermoelastic diffusive cy...

Free vibration analysis of a nonlocal thermoelastic hollow cylinder with diffusion

This paper aims to inspect the nonlocal Erigen’s elasticity model for free vibrations of thermoelastic diffusive sphere in the reference of dual-phase-lag (DPL) model of generalized thermoelasticit...

Effect of dual-phase-lag model on the vibration analysis of nonlocal generalized thermoelastic diffusive hollow sphere

High-speed face milling of AZ91 Mg alloy: Surface Integrity Investigations

Effect of High-Speed Dry Face Milling on Surface Integrity Characteristics of AZ91 Mg Alloy

In this study, optimum machining parameters are evaluated for enhancing the surface roughness and hardness of AZ91 alloy using Taguchi design of experiments with Grey Relational Analysis. Dry face milling is performed using cutting conditions determined using Taguchi L9 design and Grey Relational Analysis has been used for the optimisation of multiple objectives. Taguchi’s signal-to-noise ratio analysis is also performed individually for both characteristics and grey relational grade to identify the most influential machining parameter affecting them. Further, Analysis of Variance is carried to see the contribution of factors on both surface roughness and hardness. Finally, the predicted trends obtained from the signal-to-noise ratio are validated using confirmation experiments. The study showed the effectiveness of Taguchi design combined with Grey Relational Analysis for the multi-objective problems such as surface characteristics studies.

Dinesh Thakur

Papers

Free vibration analysis of a nonlocal thermoelastic hollow cylinder with diffusion

Effect of dual-phase-lag model on the vibration analysis of nonlocal generalized thermoelastic diffusive hollow sphere

High-speed face milling of AZ91 Mg alloy: Surface Integrity Investigations

Effect of High-Speed Dry Face Milling on Surface Integrity Characteristics of AZ91 Mg Alloy

High Speed Machining for Enhancing the AZ91 Magnesium Alloy Surface Characteristics: Influence and Optimisation of Machining Parameters