Out-of-plane impact resistance of aluminium plates subjected to low velocity impacts

An analytical model for predicting permanent plastic deflection and strain distributions in aluminium-alloy plates under low velocity impact loading

“…(2) Previous literature [10] shows that unlike the highly strain rate sensitive materials (e.g., mild steel, etc. ), aluminium-alloys (AAs) are not sensitive to the strain rate effect.…”

“…Thus, the radial displacement and the rebound deformation are ignored, and the impact responses are approximated to only the radial tensile, and radial and circumferential flexure deformations. In reality, a number of analytical or empirical models [3,9,10,14,15,[18][19][20][21] also neglected the radial displacement in order to simplify these models; despite this, the predicted results using the aforementioned models correlated well with experiments. Thus, the same simplification is adopted in this work to craft a simplified method for preliminary design purposes.…”

“…The value of impact load P can be obtained by solving Equation (34). As mentioned previously, if P is solved and determined, the out-of-plane deflection w and the impact dent depth δ can then be determined from Equations (9) and (10). Actually, in the case of dynamic loads, the inertia of the plate itself and the striking mass change with time.…”

“…As shown in previous literature [10], low velocity impact tests were conducted on AA 5083-H116 circular plates with a radius of 125 mm and three different thicknesses of 3 mm, 5 mm and 6 mm, by using a gas gun projectile launching system with an impact mass of 5.0 kg. The mechanical properties and specifications as well as experimental data of AA 5083-H116 circular plates are shown in Tables 2 and 3.…”

“…Several analytical approaches/models have been proposed to predict the response and permanent plastic deflection of the metallic plate under low velocity impact loading by means of strain energy approach and non-linear strain-hardening behaviour depicted by the exponential Cowper-Symonds function [6][7][8][9]15,[18][19][20][21] , or the Johnson-Cook model [10] . FE analysis [11][12][13] is also important for understanding the impact characteristics and permanent plastic deformation mechanism of metallic plates.…”