边界面上的倾斜移动荷载

在无限大微极正交各向异性弹性介质上覆盖弹性介质的弹性半空间的任意点上,作用着任意方向倾斜的移动荷载,给出了位移分量和应力的解析表达式．假设倾斜荷载是法向荷载和切向荷载的线性组合．利用Fourier变换采用特征值方法,并利用数值技术反演了Fourier变换．给出了铝环氧树脂复合材料的数值结果图形．     

弹性介质中正交各向异性微管的屈曲分析

已有实验表明,处于细胞质中的微管可以比自由微管承受更大的压力而不发生屈曲．基于嵌入式碳纳米管屈曲的Winkler模型,利用正交各向异性情形的Winkler模型研究了细胞质中充当细胞骨架的微管的屈曲行为．计算表明,本模型可以较好地预测嵌入弹性介质中的微管较自由微管承受更大屈曲压力这一现象,而且所得到的临界屈曲压力与微管受压屈曲的实验值吻合．同时,所得的结果也表明周围介质与微管的相互作用可以极大地提高微管抵抗屈曲的能力,该结果很好地阐释了介质与微管相互作用从而提高微管抗屈曲压力的相互作用机制．模拟结果表明,所给出的模型可以对嵌入弹性介质中的微管的屈曲行为进行很好地模拟．     

Propagation of Harmonic Waves in an Orthotropic Cylindrical Shell on Elastic Foundation

An equation is derived, using Timoshenko shell theory, to analyze axisymmetric strain fields in an orthotropic cylindrical shell on an elastic foundation. Also a dispersion equation is derived to study the natural harmonic waves in a shell depending on the properties of the elastic foundation. The wave velocities computed by the numerical method proposed are in agreement with the analytical solutions, which confirms the reliability of the results     

Plastic Incompressibility of Anisotropic Material

Some characteristics of an initially anisotropic aluminum alloy are investigated. The coefficients of transverse elastoplastic and plastic strain are calculated. It is established that the coefficients of transverse plastic strain are much different from 0.5 in directions that are not in the plane of isotropy. It is also shown that the material is plastically incompressible. The possibility of using Hill’s theory of flow with isotropic hardening to describe the inelastic behavior of the material is examinedThe study was partially sponsored by the State Fund for Basic Research of the Ministry of Education and Science of Ukraine (Grant No. 01.07/00010).__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 3, pp. 38–45, March 2005.     

Non-linear least-squares solution to the moiré hole method problem in orthotropic materials. Part 1: Residual stresses

The hole method problem relates to two inverse problems of interest: the first, most commonly addressed by practitioners, is to obtain residual stresses; the other, generally neglected, inverse problem can be posed as either a stress separation problem or a material elastic properties identification problem. In both this Paper I and Paper II, we pose and solve this dual hole method problem in an orthotropic plate, using computer generated moiré isothetics, by means of a non-linear least-squares approach. In Paper I we address the residual stress problem. In Paper II we pose the use of moiré isothetics as a means to achieve separation of stresses, but we deal with the determination of the five orthotropic elastic constants, four of which are independent.     

光弹法实测正交异性双材料界面裂纹断裂参数

采用光弹贴片法实测正交异性双材料界面裂纹尖端区域的应力应变场,进而求出界面裂纹的断裂力学参量. 将正交异性双材料板加工成拉伸试件,在聚碳酸酯贴片的单侧表面镀金属铝膜,以提高贴片的反射效率. 沿贴片后的双材料界面预制裂缝,逐渐加大载荷,得到一系列清晰的等差线条纹图. 利用正交异性双材料界面裂纹尖端应力分量表达式计算出应力强度因子. 实验表明,光弹贴片法可有效地分析正交异性双材料界面裂纹问题.     

Influence of orthotropy on displacements and stresses in nonthin cylindrical shells with elliptic cross section

An approach developed to solve boundary-value problems is used to analyze the influence of orthotropy and other factors on the displacement and stress fields in nonthin orthotropic cylindrical shells with elliptic cross-section __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 6, pp. 82–92, June 2007.     

Influence of magnetic field on free vibrations in elastodynamic problem of orthotropic hollow sphere

The effect of magnetic field on the plane vibrations for an elastodynamic orthotropic sphere is studied. Equations of elastodynamic problems of the orthotropic hollow sphere in terms of displacement are solved. The numerical results of the frequency equations in the presence of magnetic field are discussed and shown graphically. Compar-isons are made with the result in the presence and absence of magnetic field in the case of orthotropic sphere. The results show that the effect of magnetic field is very pronounced.     

Stresses in rotating heterogeneous viscoelastic composite cylinders with variable thickness

An analytical solution is presented for the rotation problem of a two-layer composite elastic cylinder under a plane strain assumption. The external cylinder has variable-thickness formulation, and is made of a heterogeneous orthotropic material. It contains a fiber-reinforced viscoelastic homogeneous isotropic solid core of uniform thickness. The thickness and elastic properties of the external cylinder are taken as power functions of the radial direction. By the boundary and continuity conditions, the radial displacement and stresses for the rotating composite cylinder are determined. The effective moduli and Illyushin’s approximation methods are used to obtain the viscoelastic solution to the problem. The effects of heterogeneity, thickness variation, constitutive, time parameters on the radial displacement, and stresses are investigated.