Elastoplastic analysis of cylindrically orthotropic composite thick-walled tube

In the present paper, Tsai-Hill Yield Criterion in a state of plane strain is derived for incompressible and compressible materials respectively. the elastoplastic stress and displacement fields of cylindrically orthotropic composite thick-walled tube under uniform radial pressure are studied. The formulas of the yield pressure, limit pressure and region of shakedown are obtained.     

Elastoplastic analysis of cylindrically orthotropic composite lamina with a circular hole under uniform pressure

This paper presents the standard parametric representation of the Tsai-Hill yieldcriterion in a state of plane stress and the equations governing the stress distribution in acylindrically orthotropic composite lamina with a circular hole under uniform pressure forthe three cases: (a) elastic state.(b) limit state and (c) elastoplastic state. The formulasfor the yield pressure and the limit pressure have been obtained.     

Limit equilibrium of an orthotropic plate weakened by a periodic row of collinear cracks

A modified δ_c-model is used to study the limiting state of an orthotropic plate weakened by a periodic row of collinear cracks and satisfying a general failure criterion. The failure mechanism of the plate is analyzed.Astudy is made of the effects of the degree of orthotropy, the biaxiality of external loading, and the geometrical parameters on the fracture process zones at the crack tips and the limiting state of the plate. The safe loading of an orthotropic viscoelastic plate with a periodic row of collinear cracks is examined. The effect of the rheological parameters on the safe-load region is studied Translated from Prikladnaya Mekhanika, Vol. 44, No. 8, pp. 126–135, August 2008.     

A study ofJ-integral of the orthotropic composite material

The relation between J-integral near model I crack tip in the orthotropic plate and displacement derivative is derived in this paper. Meanwhile, the relation between stress intensity factor K _I and displacement is also given in this paper. With sticking film moire interferometry method, the three-point bending beam is tested, thus the values of J-integral and K _I can be obtained from the displacement field, and then the truth of relation formula between J-integral and K _I in the orthotropic composite materials is experimentally verified.     

Limiting state of an elastoplastic orthotropic plate with a periodic system of collinear cracks

A modified Dugdale model is used to study the fracture of an orthotropic elastoplastic plate with a periodic system of rectilinear cracks. The material of the plate obeys a general yield criterion. The general form of solution is obtained in terms of Kolosov-Muskhelishvili potentials. The size of the plastic zone is expressed in terms of the external load and geometrical parameters. The equations for the determination of the stresses in the plastic zone and the crack opening displacement are derived. The effect of anisotropy on the formation of the plastic zones at the crack tip is examined __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 5, pp. 80–88, May 2007.     

Thermoelasticity of orthotropic composites with ellipsoidal inclusions

Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Prikladnaya Mekhanika, Vol. 26, No. 9, pp. 3–10, September, 1990.     

Elastoplastic formulation for friction with orthotropic anisotropy and rotational hardening

In various fields of engineering, it is important to clarify the frictional sliding behavior over a wide scale. In this study, we formulate an anisotropic friction model with the orthotropy and rotation of a sliding surface based on the elastoplastic theory. This model can also describe preliminary microscopic sliding and rate-dependent frictional response. Further, basic experimental results of anisotropic frictional sliding can be pertinently represented by the present model. We also employ this model with the finite element method and analyze typical frictional contact problems. We then demonstrate the effect of anisotropy parameters on the numerical results.     

Elastoplastic equilibrium of a weighable isotropic half-plane with a circular hole

The elastoplastic state of a weighable isotropic half-plane with a circular hole is studied. Complex Kolosov-Muskhelishvili functions which describe the elastic state of the half-plane are constructed. The unknown interface between the plastic and elastic regions is studied with allowance for the single-valuedness of the elastic displacements. The problem is also solved by the small-parameter method, and the two solutions are compared. Institute of Applied Mathematics and Mechanics, National Academy of Sciences of Ukraine, Donetsk, Ukraine. Translated from Prikladnaya Mekhanika, Vol. 35, No. 3, pp. 93–98, March, 1999.     

Elastic equilibrium and effective elastic constants of a cross-reinforced fiber composite

Institute of Very Hard Materials, Ukrainian Academy of Sciences, Kiev. Translated from Prikladnaya Mekhanika, Vol. 28, No. 1, pp. 47–56, January, 1992.     

Thermoelastic equilibrium of laminated,orthotropic shells with temperature-dependent characteristics

Kiev Highway Institute. Translated from Prikladnaya Mekhanika, Vol. 26, No. 9, pp. 36–43, September, 1990.     

Stress state of two collinear stamps over the surface of orthotropic materials

An exact contact analysis of two collinear stamps over the surface of orthotropic materials is performed. Eigenvalue analyses related to the governing equations are conducted, and real fundamental solutions are obtained for each eigenvalue distribution. Using Fourier sine or cosine transforms, a singular integral equation of Cauchy type is obtained. In particular, the exact solution of the reduced singular integral equation is obtained in the case of two collinear flat or cylindrical stamps. Explicit expressions for various stresses are obtained in terms of elementary functions. Numerical results are presented, and interesting observations are found. For two collinear flat stamps, detailed calculations are provided to show influences of distance between two flat stamps on the contact stress and in-plane stress. For a cylindrical stamp, influences of distance between two cylindrical stamps, mechanical loading P, and the cylindrical stamp radius R on the surface normal stress and surface in-plane stress are detailed.     

钨纤维复合材料穿甲弹芯侵彻时的自锐现象

对钨合金穿甲弹和钨纤维/Zr合金金属玻璃基复合材料穿甲弹进行了靶场对比侵彻实验。穿甲弹侵彻过程中,钨合金弹芯头部形成蘑菇头、头部晶粒被径向压扁;钨纤维复合材料弹芯头部在侵彻过程中,发生了绝热剪切破坏,具有自锐行为,且在弹芯头部形成很薄的边缘层,仅在这层中金属玻璃基体破碎,钨纤维断裂,温度升高,质量消蚀。钨纤维复合材料穿甲弹的侵彻能力明显高于钨合金穿甲弹。     

Elastic deformation of composite cylinders with cylindrically orthotropic layers

This paper provides explicit analytical expressions for displacement and stress fields in a multilayered composite cylinder with cylindrically orthotropic layers subjected to homogeneous boundary conditions. The solutions are derived in the assumption of perfect bonding between layers. The components of displacement, strain and stress are expressed in terms of the integration constants found from boundary conditions by utilizing the transfer matrix approach. Several examples are considered. The approach is validated by comparing with previously known solutions.