Dynamic fracture effects observed in a one-dimensional discrete mechanical system

¹ Emperor Alexander I Saint Petersburg State Transport University, 9, Moskovsky av., Saint Petersburg, 190031, Russia
² Saint Petersburg State University, 7-9, Universitetskaya Emb., Saint Petersburg, 199034, Russia
³ Institute of Problems of Mechanical Engineering (RAS), 61 Bolshoi av. VO, Saint Petersburg, 199178, Russia
⁴ Saint Petersburg State University of Technology, 26 Moskovsky av., Saint Petersburg, 190013, Russia

^* Corresponding author: n.kazarinov@spbu.ru

Abstract

Dynamic fracture of a one-dimensional chain of identical linear oscillators (masses connected by springs) is considered in the work. The system is supposed to consist of arbitrary but finite number of links and the first mass is supposed to be fixed. Two loading conditions are discussed: free oscillations of an initially statically prestressed chain and loading the chain with a short deformation pulse. Both problems are solved analytically for an arbitrary number of links. The obtained solutions are investigated and a dynamic fracture effect related to an explicitly discrete structure of the system is revealed: a deformation wave travelling through the chain is distorted and some links may be subjected to critical deformation. The obtained solutions for the chain are compared to the solutions of analogous problems stated for an elastic rod – a continuum counterpart of the considered discrete system. It is shown that the discussed fracture effect cannot be found in a continuous system.