Malekzadeh - Ph.D. Student, K.N.Toosi University, Tehran, Iran
Khalili - Associate Professor, Mechanical Department, K.N.Toosi University
Mittal - Professor, Applied Mechanics Department, I.I.T., New Delhi, India
Jafari - Associate Professor, Mechanical Department, K.N.Toosi University

A new equivalent three degrees-of-freedom(TDOF) spring-mass-damper (SMD) model which accommodate normal impact at any location are presented and used to predict the central and non-central low-speed impact response of composite sandwich panels,with soft/stiff flexible core.The effects of transverse flexibility of core and structural damping of panel are considered in the proposed models. Based on this model, the analytic functions describing the contact force, the transverse deflections of impactor and panel are derived. The effects of parameters such as damping effects, impactor mass and velocity are examined in details. Numerical results are presented and compared with the latest xperimental and theoretical results found in literature.

Sandwich panel,Structural damping, Low-speed Impact, Soft flexible core