軌道の動力学的強度について
1950 年 1950 巻 5 号 p. 69-82
詳細
1950 年 1950 巻 5 号 p. 69-82
The dynamical deflection of the rail and the dynamical stresses under the action of the moving wheels may become much larger than those calculated on the basis of the static formula. There are various causes which may produce such an increase in deflection and stress, some of which are discussed in three groups, a, b and c.
(a) Variation in the forces acting on the rail caused by variable spring forces on the wheel; the vertical component of the centrifugal force of the counterweights and the vertical component of the tortes in the connecting rods.
(b) Different kinds of irregularities in the shape of the wheel or rail, such as flat spots on the rim, low spots on the rail and discontinuities at the rail joints.
(c) Inertia force and internal friction of the track materials and the road bed accompanying with their vertical motion under moving loads. In discussing the causes mentioned in (a) it should be noted that their effect on the deflections and stresses in the rails can be calculated without substantial error in a statical way.
In this paper a method is developed for calculating the increase in deflections and stresses produced by the causes mentioned in (c).
