New Contact Force Estimation Procedures with Application to Low-Velocity Impact on Fiber Metal Laminate (FML) Plates

In this paper, the low-velocity impact response on fiber metal laminate (FML) plates is investigated using three new models. The boundary conditions are considered as simply supported and the behavior of the material is linear elastic. The relationships are based on classical plate theory and the Navier method is used to solve the governing equations. The mass of the impactor is considered to be large and therefore the impact response is categorized as quasi-static. In the first impact model, the contact force history is first considered as a half-sine and then the maximum contact force and contact duration are calculated. In the second model, a two-degree-of-freedom (TDOF) spring-mass system is expressed by calculating the effective contact stiffness using a fast iterative scheme. In the third model, which is expressed for the first time in this paper, the plate is considered as a series of masses and springs constructing a multi-degree-of-freedom (MDOF) spring-mass system and the applied force on the last spring is introduced as the contact force. Validation of these models is done by comparing the results with the analytical and experimental results and shows good agreement. Results show that the new MDOF sprin-mass sysem is more accuracte for calculating the deflection of the plate at the impact point rather than the TDOF sprin-mass system.