Compression Response Of Notched Composite Stiffened Panels: Analyses And Experiments

ABSTRACT An experimental and analytical evaluation of the compres- sive response of two notched composite stiffened panels representative of primary composite wing structure is pre- sented. A three-dimensional full-field image correlation tech- nique is used to measure the three displacement compo- nents over global and local areas of the test panels. Full-field displacement results obtained using the image correlation technique are presented and compared to experimental re- sults and analytical results obtained using nonlinear finite element analysis. Both global and global-local image correla- tion results are presented and discussed. 1 INTRODUCTION One of the requirements for airframe structures development is the demonstration of structural damage tolerance for a panel with a two-stringer-bay-wide notch. The response of notched panels made of composite materials and loaded in compression or tension is not well understood. Experimen- tally validated analysis methods that predict the damage initiation and growth at the notch location are needed. Such methods can eventually be used to predict the residual strength of composite primary structures. Evaluating the response of structures with discontinuities such as cutouts and damage in the form of notches requires full-field informa- tion that represents the experimental in-plane and out-of- plane displacement components of the structure. A promising method for full-field displacement measurement is the three-dimensional image correlation technique de- scribed in Ref.