Closure waves in helical compression springs with inelastic coil impact

This paper deals with the problem of spring surges taking into account coil closure. This may occur in many cases of compression springs subject to impact. Inelastic coil on coil impact conditions are assumed. The simple theory of spring surges is adopted wherein only the motion of the spring wire parallel to the axis of the spring is considered and the assumption made that each element of the spring satisfies the force-longitudinal strain relation of the whole spring, before coil closure occurs. The basic theory of coil closure with inelastic impact conditions has been given by Lee [1]$^{3}$. The spring is initially at rest and unstrained with one end fixed and the other (the impact end) is given an impulsive velocity and then either maintained at this velocity or decelerated at a constant rate. The case of a mass attached to the impact end is also considered. Conditions are obtained for which partial or complete closure of the spring occurs.