Assessing the hazard of delamination propagation in composites using numerical analysis
Jakub Wilk
Quarterly No. 1, 2015 pages 34-38
DOI:
keywords: delamination, buckling, FEM, delamination propagation, VCCT
abstract The paper presents a procedure based on numerical analyzes allowing a quick risk assessment of delamination propagation in composite structures during routine inspections. The principle of the procedure is the comparison of size and location of the defect found during maintenance checks with a set of data obtained from series of numerical analyzes in order to determine the potential for growth of the delamination. The decision then can be made regarding the inspected component - whether it can be still used or should be replaced. The data for comparison contains sets of delamination sizes corresponding to critical embedded delamination diameters derived from linear buckling analysis and nonlinear analysis of postbuckling behavior including delamination propagation. The paper shows an example of such a procedure for a structure made of carbon-epoxy laminate. A series of numerical models was created covering all the possible locations of delaminations throughout the laminate thickness. Linear buckling analysis and nonlinear analysis of postbuckling behavior were conducted using the MSC.MARC finite element commercial code. The analysis of delamination propagation is also included based on the Virtual Crack Closure Technique. The critical delamination diameters were determined for each delamination location and the bases for comparison were created.