scholarly journals A Thermodynamics-Based Nonlocal Bar-Elastic Substrate Model with Inclusion of Surface-Energy Effect

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Worathep Sae-Long ◽  
Suchart Limkatanyu ◽  
Woraphot Prachasaree ◽  
Jaroon Rungamornrat ◽  
Piti Sukontasukkul
Keyword(s):  
Surface Energy ◽  
Bulk Material ◽  
Winkler Foundation ◽  
Elastic Substrate ◽  
Energy Effect ◽  
Virtual Displacement ◽  
Differential Model ◽  
Foundation Model ◽  
Natural Boundary Conditions ◽  
Substrate Model

This paper presents a bar-elastic substrate model to investigate the axial responses of nanowire-elastic substrate systems considering the effects of nonlocality and surface energy. The thermodynamics-based strain gradient model is adopted to capture the nonlocality of the bar-bulk material while the Gurtin-Murdoch surface theory is utilized to consider the surface energy. To characterize the bar-surrounding substrate interaction, the Winkler foundation model is employed. In a direct manner, system compatibility conditions are obtained while within the framework of the virtual displacement principle, the system equilibrium condition and the corresponding natural boundary conditions are consistently obtained. Three numerical simulations are conducted to investigate the characteristics and behaviors of the nanowire-elastic substrate system: the first is conducted to reveal the capability of the proposed model to eliminate the paradoxical behavior inherent to the Eringen nonlocal differential model; the second is employed to characterize responses of the nanowire-elastic substrate system; and the third is aimed at demonstrating the dependence of the system effective Young’s modulus on several system parameters.

A Novel Beam-Elastic Substrate Model with Inclusion of Nonlocal Elasticity and Surface Energy Effects

2016 ◽  
Vol 41 (10) ◽  
pp. 4099-4113 ◽  
Author(s):  
Paitoon Ponbunyanon ◽  
Suchart Limkatanyu ◽  
Wichairat Kaewjuea ◽  
Woraphot Prachasaree ◽  
Tanan Chub-Uppakarn
Keyword(s):  
Surface Energy ◽  
Nonlocal Elasticity ◽  
Elastic Substrate ◽  
Substrate Model

Mechanics-Based Interactive Modeling for Medical Flexible Needle Insertion in Consideration of Nonlinear Factors

2016 ◽  
Vol 11 (1) ◽  
Author(s):  
Shan Jiang ◽  
Xingji Wang
Keyword(s):  
Soft Tissue ◽  
Kinematic Model ◽  
Needle Insertion ◽  
Winkler Foundation ◽  
Nonlinear Characteristics ◽  
Deformation Control ◽  
Needle Deflection ◽  
Iteration Cycle ◽  
Foundation Model ◽  
Sensitivity Studies

A mechanics-based model of flexible needle insertion into soft tissue is presented in this paper. Different from the existing kinematic model, a new model has been established based on the quasi-static principle, which also incorporates the dynamics of needle motions. In order to increase the accuracy of the model, nonlinear characteristics of the flexible needle and the soft tissue are both taken into account. The nonlinear Winkler foundation model and the modified Euler–Bernoulli theory are applied in this study, providing a theoretical framework to study insertion and deformation of needles. Galerkin method and iteration cycle analysis are applied in solving a series of deformation control equations to obtain the needle deflection. The parameters used in the mechanics-based model are obtained from the needle force and needle insertion experiment. Sensitivity studies show that the model can respond reasonably to changes in response to variations in different parameters. A 50 mm needle insertion simulation and a 50 mm corresponding needle insertion experiment are conducted to prove the validity of the model. At last, a study on different needle tip bevel demonstrates that the mechanics-based model can precisely predict the needle deflection when more than one parameter is changed. The solution can also be used in optimizing trajectory of the needle tip, enabling the needle to reach the target without touching important physiological structures such as blood vessels with the help of dynamic trajectory planning.

Surface energy effect on boiling heat transfer

2005 ◽  
Vol 41 (12) ◽  
pp. 1043-1047 ◽  
Author(s):  
Atul P. Patil ◽  
Vijaya C. B. Vittala
Keyword(s):  
Heat Transfer ◽  
Surface Energy ◽  
Boiling Heat Transfer ◽  
Energy Effect ◽  
Surface Energy Effect

Curling Stress Equation for Transverse Joint Edge of a Concrete Pavement Slab Based on Finite-Element Method Analysis

1996 ◽  
Vol 1525 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Tatsuo Nishizawa ◽  
Tadashi Fukuda ◽  
Saburo Matsuno ◽  
Kenji Himeno
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fem Analysis ◽  
Concrete Pavement ◽  
Winkler Foundation ◽  
Stress Equation ◽  
The Past ◽  
Transverse Joint ◽  
Foundation Model ◽  
Element Method

In the design of concrete pavement, curling stresses caused by the temperature difference between the top and bottom surfaces of the slab should be calculated at the transverse joint edge in some cases. However, no such equation has been developed in the past. Accordingly, a curling stress equation was developed based on stress analysis using the finite-element method (FEM). In this FEM analysis, a concrete pavement and its transverse joint were expressed by means of a thin plate–Winkler foundation model and a spring joint model, respectively. Multiregression analysis was applied to the results of the FEM numerical calculation and, consequently, a curling stress equation was obtained. After comparing the calculated results of the equation with curling stress equations developed in the past, it was confirmed that the equation was valid and practical.

Study on a New Foundation Stiffness Calculation Model

2012 ◽  
Vol 166-169 ◽  
pp. 1258-1261
Author(s):  
Yan Jun Ma ◽  
Bin Yan ◽  
Jing Zhang
Keyword(s):  
Calculation Model ◽  
Summation Method ◽  
Winkler Foundation ◽  
Foundation Soil ◽  
Foundation Model

This paper combined the feature of Winkler foundation model and base model of limited compressible layer based on the layer-wise summation method, on condition that considering the feature of foundation soil, to derived from a newly foundation stiffness calculation model and to verify it.

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