Analysis of penetration of axisymmetric projectiles into semi-infinite targets

The process of penetration of a projectile into a semi-infinitetarget is studied in this paper. Using certain assumptions, the propagation of plastic wave in the target is analyzed and the pressure on the surface of penetrator is given. The results calculated from the formulas of this paper agree well with experimental data and numerical results.     

A criterion for the onset of growth of two shear cracks in an elastic body under plane-strain conditions

The Wiener-Hopf method is used to find a solution to a symmetric problem that gives a criterion for the onset of growth of long shear cracks emanating from a corner point on the boundary of a hole and filled with a plastic material __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 4, pp. 83–90, April 2006.     

铝单晶体潜在硬化的指向性行为研究

应用高纯铝单晶体，采用偏离弹性线法定义其在潜在滑移系统在屈服应力，研究了潜在滑移系在正负两个滑移方向上的屈服及应变硬化行为。结果表明，潜在滑移系负行为的差异要远远小于动滑移系的Ｂａｕｓｃｈｉｎｇｅｒ效应，其正负方向的屈服应力一般均等于或略小于预应变时的最大分切应力，大大高于动滑移系的负向屈服应力，潜在滑移系和原始滑移系的相对取向及预应变的大小对单晶体潜在移系在潜在硬化的影响不大，但对其起始过渡区应     

Stability of conical shells made of composites with one plane of elastic symmetry

The paper proposes a technique for stability analysis of anisotropic laminated thin shells of revolution made of a composite with one plane of symmetry. The technique is used for numerical analysis of truncated cones made of binder-impregnated filaments continuously wound along geodesic lines. It is shown that the effect of low symmetry on the critical loads depends not only on the number of laminas, but also on the cone angle __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 6, pp. 93–101, June 2007.     

偏心率效应对金属圆柱管轴压性能的影响

用含有偏心率因子的直链塑性铰叠缩模型来分析金属圆柱管轴向压缩能量吸收，根据能量原理推导了瞬时载荷，从而获得压缩过程的载荷-位移曲线．讨论了偏心率对平均压缩载荷和载荷-位移曲线形貌的影响．实验结果与模型分析符合得很好．     

Numerical plane stress elastic–perfectly plastic crack analysis under Tresca yield condition with comparison to Dugdale plastic strip model

A number of plane stress numerical analyses of the mode I elastoplastic fracture mechanics problem have been performed in the past using the Huber–Mises yield criterion. This study employs instead the Tresca yield condition using an incremental theory of plasticity for a stationary crack. A commercial finite element program is used to solve the opening mode of fracture problem (mode I) for a square plate containing a central crack under generalized plane stress loading conditions. A biaxial uniform tensile traction is applied to the edges of a thin plate composed of a linear elastic non-work hardening material under small strain assumptions. The finite element results are compared with the analytical predictions of the Dugdale plastic strip model for a crack in an infinite plate subject to a biaxial uniform load at infinity.     

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.     

Refinement of the plastic-zone boundary in the vicinity of a crack tip for the quasiviscous and viscous types of fracture

A refined solution of the elastoplastic problem of an insulated mode I crack in a thin plate of reasonably large dimensions is obtained. Estimates of the plastic zone in the vicinity of the crack tip are given for quasiviscous and viscous types of fracture.Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 1, pp. 126–132, January–February, 2005     

一种新的弹塑性杂交应力元法

本文基于一个改进的弹塑性的Hellinger/Reis■ner 混合变分原理构造了一种用于解弹塑性问题的四节点等参杂交应力元.新的模型中,在单元内增加了等效应力增量、塑性等效应变增量及不协调位移变量,从而使单元内的屈服准则及流动法则平均得到满足,不协调位移改进了单元应力精度.计算表明,新的模型可以提高弹塑性杂交法的精度和计算效率.     

ε-CL-20/F_(2311) PBXs力学性能和结合能的分子动力学模拟

本文应用分子动力学(MD)模拟方法,研究高能量密度化合物六硝基六氮杂异伍兹烷(ε-CL-20)与常用高聚物粘结剂F2311所构成的CL-20/F2311高聚物粘结炸药(PBXs)的力学性能和结合能随温度和高聚物浓度而变化的规律.结果表明,添加高聚物于主体炸药中,使其弹性模量减小,表明刚性减小,弹性增大,机械力学性能大为改善;在一定范围内,随高聚物F2311在PBXs中浓度的增加,体系结合能从正值变为负值,而随温度升高,体系的结合能变化不是很明显.