Drop shock analysis of products with cantilever beam type vulnerable parts and elastic constraints

Here, considering drop shock of packaging systems with cantilever beam type vulnerable parts, in order to improve the reliability of their drop shock, an elastic constraint, i.e., a support spring was exerted between an elastic vulnerable part and rigid product body. Based on Hamilton variational principle, the rigid-flexible coupled nonlinear dynamic equation of the system during drop shock was established. The frequency of a cantilever beam type vulnerable part and its maximum configuration and stress distribution in impact process were numerically discussed. The results showed that the natural frequency of the elastic vulnerable part decreases with increase in end mass, and increases with increase in end support stiffness; the elastic restraint has an obvious suppressing action on impact response of the cantilever beam type vulnerable part; under different support conditions, the maximum displacement response and the maximum internal stress of the vulnerable part are obviously reduced, and the end concentrated support case has the best effect, when the dimensionless support stiffness is 0-30, the suppressing effect on shock response is the most obvious. © 2021, Editorial Office of Journal of Vibration and Shock. All right reserved.