Effects of adhesive parameters on out-of-plane compression and compression fatigue response of adhesively bonded sandwiches with pyramidal core

Effects of key adhesive parameters such as curing temperature and the amount of adhesive on the out-of-plane compression and fatigue strength of sandwich panels with pyramidal core are experimentally investigated and compared with those of theoretical analysis. It is shown that two different curing temperatures lead to the different liquidity of surplus adhesive squeezed out and then the shapes of spew fillet. Sandwich panels with arc spew fillets have higher compression strength than those with rounded spew fillets. With the increase of the amount of adhesive, the out-of-plane compression strength of those sandwich panels clearly increases firstly and then gradually tends to the theoretical value. By analysis of the S-N fatigue curves of four types of sandwich specimens, the shape of spew fillet, the amount of adhesive and the loading ratios are identified as the key factors governing the compression fatigue properties of truss-cored sandwich structures.