The Effects of Delamination on the Fatigue Behavior of Composite Structures

The aim of the present study is to investigate the role played by delamination on the fatigue behavior of centrally holed CFRP laminates. To reach this objective, both theoretical and experimental studies were performed. As to the theoretical analysis and the relevant numerical predictions of the 3D state of stress, the study proposes the use of a finite element procedure based on a multi-layer higher-order laminate theory developed by the authors in conjunction with the application of an interlaminar failure criterion. The approach assumes that significant information on the fatigue life of holed laminate can be obtained by performing a static prediction only. Two types of rectangular laminates with stacking sequences [+45)4/(-45)4] s , and [0/90] 3 manufactured with T300/934 are examined. The static and the fatigue failure of the above mentioned laminates were then investigated in a series of experiments in order to verify the initiation of delamination both in the static case and during the fatigue loading process, ultrasonic nondestructive inspections were also made. The obtained results show a significant correspondence between the experimental static and fatigue behavior of the laminates and the theoretical predictions. They show also that an efficient numerical tool of the 3D state of stress prediction is used.

[1]  Paolo Gaudenzi,et al.  MULTI-LAYER HIGHER-ORDER FINITE ELEMENTS FOR THE ANALYSIS OF FREE-EDGE STRESSES IN COMPOSITE LAMINATES , 1998 .

[2]  R. Barboni,et al.  The Influence of Interlaminar Stresses on Fatigue Behaviour of Notched Composite Laminates , 1996 .

[3]  Ming-Hwa R. Jen,et al.  Initiation and Propagation of Delamination in a Centrally Notched Composite Laminate , 1993 .

[4]  C. Sun,et al.  Matrix Cracking and Delamination Prediction in Graphite/Epoxy Laminates , 1992 .

[5]  Chien-Chang Lin,et al.  Method for Calculating the Interlaminar Stresses in Symmetric Laminates Containing a Circular Hole , 1991 .

[6]  Kenneth Reifsnider,et al.  Study of the Onset of Delamination at Holes in Composite Laminates , 1990 .

[7]  John C. Brewer,et al.  Quadratic Stress Criterion for Initiation of Delamination , 1988 .

[8]  Charles E.S. Ueng,et al.  A Simplified Approach for Interlaminar Stresses Around a Hole in [0/90]s Laminates , 1988 .

[9]  M. Persson,et al.  On the Prediction of the Initiation of Delamination in a [0/90]S Laminate with a Circular Hole , 1984 .

[10]  T. S. Sankar,et al.  The Effect of Geometry on Interlaminar Stresses of [0/90]s Composite Laminates with Circular Holes , 1984 .

[11]  Ran Y. Kim,et al.  Experimental and Analytical Studies On the Onset of Delamination in Laminated Composites , 1984 .

[12]  E. F. Rybicki,et al.  Effect of Stacking Sequence and Lay-Up Angle on Free Edge Stresses Around a Hole in a Laminated Plate Under Tension , 1978 .

[13]  Paolo Gaudenzi,et al.  On the use of a multilayer higher-order theory for the stress analysis around a circular hole of laminates under tension , 1995 .

[14]  Paolo Gaudenzi,et al.  A finite element evaluation of single-layer and multi-layer theories for the analysis of laminated plates , 1995 .

[15]  J. Reddy.  An evaluation of equivalent-single-layer and layerwise theories of composite laminates , 1993 .

[16]  Chien-chang Lin,et al.  Prediction for delamination initiation around holes in symmetric laminates , 1992 .

[17]  Ramesh Talreja,et al.  Fatigue of composite materials , 1987 .

[18]  Jacob Avrashi,et al.  Interlaminar stress analysis for laminated plates containing a curvilinear hole , 1985 .

[19]  Satya N. Atluri,et al.  Stress analysis of holes in angle-ply laminates: An efficient assumed stress “special-hole-element” approach and a simple estimation method , 1982 .