experimental investigation of impact damage response of sandwich panels with epoxy/woven-fiberglass/nano-silica composite face-sheets

In this paper by using the threepoint bending and low velocity impact tests, the impact damage response of polyurethane cored sandwich panels with hybrid nanocomposites facesheets is investigated. the facesheets are made of epoxy/wovenfiberglass/ nanosilica composite. threepoint bending test is used for determination of static threshold delamination force, and static and dynamic interlaminar shear strength has been calculated. furthermore, low velocity impact tests are performed on a sandwich panel and contact forces history, lateral deflection of the contact point and the absorbed energy of top facesheets are obtained. the dynamic threshold delamination force has been used to predict the delamination damage mode in low velocity impact tests on sandwich panel. finally, the delamination damage area is investigated theoretically and experimentally and the correction factor is associated with allowable shear stress is determined. moreover, the effect of nanosilica particles on delaminations threshold forces, interlaminar shear strengths, contact force, contact duration, deflection of contact point, energy absorption of top facesheet and damage area caused by delamination is studied.