Effect of core shape on debonding failure of composite sandwich panels with foam-filled corrugated core

One of the major failure modes in composite sandwich structures is the separation between skins and core. In this study, the effect of employing foam filled composite corrugated core on the skin/core debonding (resistance to separation between skin and core) is investigated both experimentally and numerically. To this aim, triangular corrugated core specimens are manufactured and compared with reference specimens only made of PVC foam core in terms of skin/core debonding under bending loading. The corrugated composite laminates are fabricated using the hand layup method. Also, the Vacuumed Infusion Process (VIP) is employed to join the skins to the core with greater quality. Utilizing an End Notched Shear (ENS) fixture, three point bending tests are performed on the manufactured sandwich composite panels. The results reveal that the resistance to separation capacity and flexural stiffness of sandwich composite has been increased about 170% and 76%, respectively by using a triangular corrugated core. The Cohesive Zone Model (CZM) with appropriate cohesive law in ABAQUS finite element software is used to model the progressive face/core interfaces debonding the difference between experimental and numerical results in predicting the maximum born load before the skin/core separation is about 6 % in simple core specimens and 3% in triangular corrugated core specimens.

Automated summary

This study investigates the effect of employing foam filled composite corrugated core on the separation between skins and core in composite sandwich structures. Experimental and numerical methods are used to compare the performance of triangular corrugated core specimens to reference specimens made of PVC foam core. The results show that using a triangular corrugated core can significantly increase the resistance to separation and flexural stiffness of the sandwich composite. The numerical model can accurately predict the maximum load before skin/core separation, with a slight difference from the experimental results.