Showing papers by "Liao-Liang Ke published in 2022"
TL;DR: In this paper , a free vibration analysis of functionally graded material (FGM) plates that are partially submerged in an incompressible, inviscid fluid is presented, where the plate is modeled based on the Mindlin Plate Theory (MPT), and the fluid loading effect on the FGM plates is modeled using the method of added mass.
4 citations
TL;DR: In this article , a new size distribution law of the truncation areas for fractal surfaces is proposed and validated by a realistic rough surface and a 3D Weierstrass-Mandelbrot (WM) function.
4 citations
TL;DR: In this article , an experimental investigation is conducted to evaluate the fretting wear behavior and the frictional heating behavior of PEEK and three kinds of polyetheretherketone-based composites under the dry sliding and water lubricated conditions.
4 citations
TL;DR: In this paper , a multi-physics electrical contact model is developed to predict the contact pressure, temperature, and electric current density (ECD) distributions on the contact surface, taking the interfacial electrical resistance and its resultant Joule heating into account.
3 citations
TL;DR: In this paper , a new class of composites reinforced by axially functionally graded fibers with high stiffness in the middle, degrading to low stiffness at the ends is proposed, which can effectively alleviate the shear stress concentration on the fiber-matrix interface.
Abstract: Inspired by the composite structure of the wood cell wall, we propose in this paper a new class of composites reinforced by axially functionally graded fibers with high stiffness in the middle, degrading to low stiffness at the ends. Analysis based on both analytical shear-lag model and Finite Element model demonstrates that such a functionally graded design can effectively alleviate the shear stress concentration on the fiber-matrix interface. Besides, we find that, by reducing the stiffness of the fiber end, the interfacial debonding is significantly postponed thus the strength of the composite is improved. A detailed study on the debonding process is conducted and we characterize a distinctive catastrophic propagation mode of the interfacial crack, indicating that the functionally graded fiber enhances the mechanical performance of the composite by raising the threshold of interfacial debonding. Moreover, some of the design parameters governing the fiber modulus profile are discussed with regard to their effects on the mechanical properties of the composite. This work sheds light on achieving high performance composites with relatively poor intrinsic interface properties.
3 citations
TL;DR: In this paper , an analytical model based on the modified couple stress theory and Timoshenko beam theory is developed to study the vibrational power flow of a microbeam with a crack, where the open edge crack on the microbeam is modeled as a rotational spring, which connects the two segments of the microbe separated by the crack location.
3 citations
TL;DR: In this article , the authors analyzed the nonlinear vibration behavior of two-layer bi-material beams by using the Euler beam theory and Timoshenko beam theory, and showed that the softening-spring nonlinearity is dependent on the thickness ratio, Young's modulus ratio, vibration amplitude, layer number and boundary condition.
Abstract: The purpose of this study is to analyze the nonlinear vibration behavior of two-layer bi-material beams by using the Euler beam theory and Timoshenko beam theory. It is assumed that material properties satisfy a power law distribution along the thickness direction. The differential quadrature (DQ) method in conjunction with an iterative algorithm is employed to solve the nonlinear governing equations for two-layer bi-material beams. Numerical results are presented to show the influence of Young’s modulus ratio and thickness ratio on nonlinear frequency ratio–amplitude curves of two-layer bi-material beams. It is observed that the nonlinear frequency ratio–amplitude curves are unsymmetrical with the hinged end because of bending-extension coupling effect in two-layer beams. It is also observed that the hinged–hinged two-layer beams may occur the softening-spring nonlinearity when the amplitude of oscillation is small. This softening-spring nonlinearity is dependent on the thickness ratio, Young’s modulus ratio, vibration amplitude, layer number and boundary condition. The greater the difference of material properties between the two layers is, the more obvious the softening-spring nonlinearity becomes.
2 citations
TL;DR: In this article , a new relatively simple numerical model of the behavior of lubrication parameters in a line lightly loaded contact of double-coated elastic cylinders has been developed, where the main part of the elastic displacements of the contact surfaces is represented by simple Winkler like contributions.
Abstract: The main goal of this paper is to consider formulation and solution of a lubrication problem based on the expressions for elastic surface displacements derived asymptotically from an exact solution for a loaded double coated elastic substrate which are valid within a certain region of the problem input parameters. Therefore, a new relatively simple numerical model of the behavior of lubrication parameters in a line lightly loaded contact of double coated elastic cylinders has been developed. For simplicity materials and coatings of both cylinders are considered identical. The main part of the elastic displacements of the contact surfaces is represented by simple Winkler like contributions. The problem is reduced to a numerical solution of a system of two transcendent equations. The formulas for lubrication parameters such as distributions of contact pressure, gap, lubrication film thickness, shear stress, coefficient of friction, and contact energy loss were derived and used for specific calculations. Generally, compared to lubrication parameters in the contact of rigid solids without coatings the effect of the double coating resulted in reduced (up to 60% or more) contact pressure, increased contact area and film thickness as well as some reduction of frictional forces and energy losses. Some specific results for the obtained solutions are provided.
2 citations
TL;DR: In this article , the effect of surface roughness on the linear and nonlinear free vibration behaviors of microbeams based on the strain gradient theory was studied, and a closed-form solution of strain gradient beams (SGBs) was obtained by solving a general sixth-order differential equation.
1 citations
1 citations
TL;DR: In this article , the authors studied the coupling between sorption and deformation by an atomistic slit pore model with the help of molecular simulations and found that the sorption-induced deformation can shift between expansion and contraction by tuning the surface morphology.
TL;DR: In this article , a constitutive model of the FG-SMA beam, considering the influence of the temperature variation and the tension-compression asymmetry coefficient, was established, which was solved using the Newton-Raphson algorithm.
Abstract: The mechanical properties of functional-graded shape memory alloy (FG-SMA) is of highly significance for its applications and structural design. This paper establishes a constitutive model of the FG-SMA beam, considering the influence of the temperature variation and the tension-compression asymmetry coefficient. The fiber element method and the virtual work principle were employed to establish the governing equation of the bending of FG-SMA beam, which is solved using the Newton–Raphson algorithm. Furthermore, the effect of the tension-compression asymmetry coefficient, temperature, gradient index, bending moment, and axial load on the mechanical properties of the FG-SMA beams was analyzed. The results showed that the tension-compression asymmetry coefficient, gradient index, bending moment, and axial load significantly have relatively obvious influence on the cross-sectional mechanical response of the FG-SMA beams, while the effect of the temperature was not noticeable.