Papers by Keyword: Orthotropic

Abstract: The orthotropic bi-material plane interface end of a flat lap is studied by constructing new stress functions and using the composite complex function method of material fracture. When the characteristic equations’ discriminates and, the theoretical formulas of stress fields, displacement fields and the stress intensity factor around the flat lap interface end are derived, indicating that there is no oscillatory singularity. There are multiple stress singularities of the orthotropic bi-material plane flat lap interface end.

Abstract: This paper presents a multiscale method to estimate the elastic property of the 13_3 microtubule. A microtubule is viewed as being formed by rolling up its planar encounter into the tubular shape, and the transformation is written into a set of equations with three geometrical parameters. The representative cell is chosen as an unit of two pairs of tubulin momoners. With the appropriate longitudinal and lateral interactive potentials, the strain energy density is calculated by deviding the cell’s energy by its spacial volume. The elastic property of microtubule is determined by minimizing the strain energy density, and the elastic constants are calculated in the thereotical scheme of orthotropic elasticity due to the geometrical meanings of the induced parameters. The advantage of the proposed method and its future application are discussed.

Abstract: Interdigitated electrodes piezo-actuator has been widely applied in smart structures. Based on the analogy between the equation of inverse piezoelectric effect and piezoelectric strain decomposition, the driving voltage is simulated for mechanical load in this paper. Firstly, stress simulation method of piezoelectric actuators can be employed to the static displacement of piezoelectric cantilever beam and wing-box structure. Then, a modified coefficient is needed to modify the ferroelectric properties of the high voltage of the interdigitated electrodes piezoelectric composite materials. Finally, the experimental results indicate that stress simulation method of piezoelectric actuators is valid, and it can accurately simulate deformation of piezoelectric smart structures. The Error is little, which meets simulation requirements.

Abstract: The orthotropic bi-material plane interface end of a flat lap is studied by constructing new stress functions and using the composite complex function method of material fracture. When the characteristic equations’ discriminates and , the theoretical formulas of stress fields, displacement fields and the stress intensity factor around the flat lap interface end are derived, indicating that there is no oscillatory singularity. There are multiple stress singularities of the orthotropic bi-material plane flat lap interface end.

Abstract: The problem of orthotropic composite materials semi-infinite interfacial crack was studied, by constructing new stress functions and employing the method of composite material complex. In the case that the secular equations’ discriminates the and theoretical solutions to the stress fields and the displacement fields near semi-infinite interface crack tip without oscillation and inter-embedding between the interfaces of the crack are obtained, a comparison with finite element example was done to verify the correction of theoretical solution.

Abstract: In this paper, the yield condition of Hill’s orthotropic yield criterion under axial symmetric plane stress state was discussed. The yield function of orthotropic material was proposed and the analytical solution to meet the condition of equations of equilibrium and compatibility under axial symmetric plane stress state is obtained, in which the conditions of power hardening materials was considered. The research result indicates that hardening coefficient and anisotropic parameter have substantial influence over stress and strain. However, in the presence of the coefficient R90=H/F，the influence appears to be quite weak.

Abstract: The problem of orthotropic bi-materials semi-infinite interfacial crack was studied, by constructing new stress functions and using composite complex functions methods of material fracture on plane. It overcame oscillation singularity of stress and existing theoretical solution. When secular equations’ discriminations are and , the theoretical solutions to the stress fields and the displacements fields of semi-infinite interface crack between two dissimilar orthotropic composite materials near the crack tip are obtained.

Abstract: This paper describes for breaking behaviors on the surface layer of a white-coated paperboard during indentation of a center bevel blade. Cutting load response of the paperboard was measured regarding the indentation depth of the blade and the deformation flow in a side view of the paperboard was observed by a CCD camera in order to investigate the effect of blade tip angle on the surface failures of the paperboard. The surface breaking strength of paperboard was analyzed by using Finite Element Method (FEM). Through the experiment and FEM simulation, the followings were revealed. 1) There is a certain critical value of tip angle C at which an inflection load response disappears and also the surface failures are restricted. 2) When the tip angle is less than the C, there is an inflection point as the surface-layer breaking and its surface breaking point was strongly related to the maximum principal stress on the surface. 3) After the surface breaking, the deformation flow and its cutting resistance are strongly affected by the de-laminated and the raised-up of the inner-layer.

Abstract: Orthotropic bi-materials interfacial crack was studied, by constructing new stress function and using composite complex function method of material fracture. When secular equations’ discriminant 1 0
< and 2 0
< , the theoretical solutions of stress fields without oscillation singularity and displacement fields without embedding of upper and lower sides are derived.

Abstract: Dynamic problems of Yoffe mode crack are studied under antiplane shear impact in infinite orthotropic functionally graded materials. The shear modules in two directions are assumed to vary in terms with power function form of dual parameters of arbitrary time power. By using integral transform-dual integral equations method, the stress field and dynamic stress intensity factor near crack tip are obtained. And the influences of material in homogenous coefficient and graded parameters and crack moving speed to dynamic stress intensity factor are analyzed in virtue of Matlab software. Results show that the dimensionless dynamic stress intensity factor will decrease with the increase of moving speed of crack, which is opposite to the result of the dynamic problem of infinite strip in FGM. And the dimensionless dynamic stress intensity factor will decrease with the increase of graded parameters and rise with the increase of material in homogenous coefficient.