Mixed Finite Element Method for End‐Notched Flexure Test
Publication: Journal of Engineering Mechanics
Volume 116, Issue 11
Abstract
To permit more efficient use of the experimental data in the end‐notched flexure (ENF) test, a mixed finite element method is used to model the macromechanical situation with a small number of four‐noded quadrilateral elements. This small number of elements is made possible by the development of two types of specialty finite elements (constant shear‐strain bending element and delamination bending element) within the Hu‐Washizu variational principle. With these elements it is possible to satisfy exactly the kinematic boundary conditions of the ENF test—especially at the point of zero slope. Assuming linear elastic fracture mechanics, the critical interlaminar fracture toughness is found at one critical load by calculating the difference between the strain energy at the initial crack length and that for an incremental increase in crack length. For a 32‐ply, unidirectional, linear transversely isotropic laminate of varying thickness, the values for calculated by this finite element model compared well with the results obtained from a previously developed mixed experimental and structural model.
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Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 116 • Issue 11 • November 1990
Pages: 2521 - 2531
Copyright
Copyright © 1990 ASCE.
History
Published online: Nov 1, 1990
Published in print: Nov 1990
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