STATIC AND DYNAMIC THROUGH THICKNESS LAMINA PROPERTIES OF THICK LAMINATES

Thick laminates are increasingly present in large composites structures such as wind turbine blades. Different factors are suspected to be involved in the decreased static and dynamic performance of thick laminates. These include the effect of self-heating, the scaling effect, and the manufacturing process influence. The aim of this work is to study the through thickness variation of static and dynamic lamina properties in thick laminates. For this purpose, 60-70 mm thick unidirectional GFRP/epoxy infused panels were divided in sub-laminates with the help of peel-ply layers at different thickness positions. From each sub-laminate, 4 mm thick compression coupons with integrated tabs and tension coupons were manufactured. In order to characterize the manufacturing influence, the 60-70 mm thick laminates plates were monitored during the manufacturing. Static and fatigue tests were carried out for each sub-laminate in order to study the lamina properties at different thicknesses positions through the thickness. The present work reports temperature profiles and residual stress measurements through the thickness recorded during the manufacturing, as well as experimental data from static and fatigue tests (S-N curves) of sub-laminates obtained at different thickness positions.