Mechanical conditions for fracture of anisotropic bodies and their geometry in stress space

The conditions for fracture of anisotropic bodies and theirgeometry in stress space are proposed in this paper.The an-alytical formulae expressing the fracture conditions are es-tablished from the viewpoint of energy theory for crack pro-pagation.In stress space the limiting surface corresponding to thefracture conditions derived for anisotropic solids is quadra-tic.It is an ellipsoid in case the mean stress is greaterthan zero and it is hyperboloid in case the mean stress is smal-ler than zero.The conclusions formed by the author in the present paperhave certain generality.Some results obtained by predeces-sors appear to be special cases with respect to the presenttheory.     

滑冰运动初探

建立了滑冰运动的一种力学模型并应用非完整力学中的Routh方程对其求解。详细分析了滑冰时的两种局部有意义的常见的定常运动,计算结果与实际观察到的现象是一致的。     

PRELIMINARY ANALYSIS OF SKATING MOTION

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