Dynamic characteristics of laminated woven E-glass-epoxy composite plates subjected to low velocity heavy mass impact

The main goal of this study is to examine the size effects including both in-plane dimensional and thickness effects for laminated woven E-glass-epoxy composite subjected to low velocity heavy mass impact. The studies have been carried out with plate dimensions of 150 x 150 mm, 150 x 100 mm and 150 x 50 mm for in-plane dimensional effect. Two nominal thicknesses with averages of 1.4 and 2.8 mm are used for studying the thickness effect. The impact testings are conducted with a vertical drop-weight testing machine developed in the department laboratory. Affixed to the drop-weight device, a piezoelectric force transducer, localized in the hemispherical impactor nose, yields the complete force versus time history of impact event. Impact tests are performed at increasing impact velocities 1, 2 and 3 m/s and impactor mass of 2.6 kg on clamped plates. A numerical evaluation of these specimens is also carried out by using 3DIMPACT transient dynamic finite element analysis code. The contact forces between the impactor and the composite plate as functions of time, transient stresses during impact and the predicted delamination sizes of composites are found numerically.