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61.
62.
A contact problem of two elastic convex and axially symmetric solids heated (or cooled) to temperatures of different values is considered. Pertinent formulae have been derived for relations between the contact pressure, geometrical characteristics of the solids and distributions of heat flux over the contacting region. We have analysed: 1. The problem of the loss of the contact between two solids pressed together with active heat fluxes. We discuss the cases for which the contact of the axially symmetric solids can take the form of a circle, or an annulus. 2. The problem of a paradox when the mathematically well posed contact problem of thermoelasticity leads to a physically unacceptable solution with a region of overlapping materials. Here we discuss a generalization of the cooled sphere paradox. The heat flux functions are continuously differentiable, of constant sign. The conditions have been derived for the cases when the paradox can be avoided. 相似文献
63.
A. M. Khludnev 《Journal of Applied Mechanics and Technical Physics》2005,46(5):717-729
The equilibrium problem for an elastic body containing a crack on the interface between two media is considered. It is proved that there exist invariant (independent of the integration surface) integrals in this problem. The existence of invariant integrals is also established in the problem of a contact between an elastic body and a rigid stamp. Nonlinear boundary conditions of mutual non-penetration are prescribed on the contact boundaries. The physical meaning of invariant integrals is established.__________Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 5, pp. 123–137, September–October, 2005. 相似文献
64.
P. P. Krasnyuk 《International Applied Mechanics》2005,41(12):1357-1367
A mathematical formulation is given and a solution is found to the quasistatic contact problem of thermoelasticity for a rigid
heat-conducting punch moving over an elastic layer with fixed base. The interaction is accompanied by heating due to frictional
forces obeying Amonton’s law. The problem is reduced to a system of integral equations with time-varying limits of integration.
The structure of these equations depends on the type of thermal and physical conditions on the contact surface. An algorithm
is proposed for the numerical solution of this kind of equations. The variation in the contact pressure and contact area with
time is studied
__________
Translated from Prikladnaya Mekhanika, Vol. 41, No. 12, pp. 35–46, December 2005. 相似文献
65.
We consider the system of elastostatics for an elastic medium consisting of an imperfection of small diameter, embedded in a homogeneous reference medium. The Lamé constants of the imperfection are different from those of the background medium. We establish a complete asymptotic formula for the displacement vector in terms of the reference Lamé constants, the location of the imperfection and its geometry. Our derivation is rigorous, and based on layer potential techniques. The asymptotic expansions in this paper are valid for an elastic imperfection with Lipschitz boundaries. In the course of derivation of the asymptotic formula, we introduce the concept of (generalized) elastic moment tensors (Pólya–Szegö tensor) and prove that the first order elastic moment tensor is symmetric and positive (negative)-definite. We also obtain estimation of its eigenvalue. We then apply these asymptotic formulas for the purpose of identifying with high precision the order of magnitude of the diameter of the elastic inclusion, its location, and its elastic moment tensors. 相似文献
66.
V. Z. Stankevich B. M. Stasyuk O. M. Khai 《Journal of Applied Mechanics and Technical Physics》2005,46(1):124-128
The three-dimensional dynamic problem of coplanar circular cracks in an elastic half-space with a clamped boundary condition is considered. The crack faces are subjected to harmonic loads. The problem is reduced to a system of two-dimensional boundary integral equations of the type of the Helmholtz potential for unknown discontinuities in the displacements of the opposite faces of the cracks. The stress intensity factors at the crack contours are obtained and discussed.Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 1, pp. 153–159, January–February, 2005 相似文献
67.
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. 相似文献
68.
A method is proposed to study the stress concentration around a shallow spheroidal crack in an infinite elastic body. The
stress concentration is due to the diffraction of a low-frequency plane longitudinal wave by the crack. The direction of wave
propagation is established in which the combined concentration of mode I and mode II stresses is maximum
__________
Translated from Prikladnaya Mekhanika, Vol. 42, No. 1, pp. 70–77, January 2006. 相似文献
69.
讨论螺旋细杆的特殊形式扭转振动,即均匀扭转振动.以非圆截面杆和有原始曲率的圆截面杆为研究对象.杆作均匀扭转振动时各截面有相同的扭角变化规律,且杆中心线的几何形状不受振动过程的影响.研究表明,扭振来源于杆截面的非对称性及杆的原始曲率.杆的扭振规律与单摆运动相似,其动力学方程存在精确解.圆环杆的均匀扭振为螺旋杆的倾角为零时的特例. 相似文献
70.
弹性地基梁振动特性的近似分析方法 总被引:4,自引:1,他引:4
文中介绍了用模态摄动法分析复杂情况下弹性地基梁动力特性的近似方法。这一方法中可考虑纵向钢筋以及变地基弹性系数对弹性地基梁振动特性的影响,通过算例说明了这一方法的有效性。 相似文献