A two-dimensional model of a film bonded to an elastic substrate is propose
d for simulating crack propagation paths in thin elastic films. Specific ex
amples are presented for films subject to equi-biaxial residual tensile str
ess. Single and multiple crack geometries are considered with a view to elu
cidating some of the crack patterns which are observed to develop. Tendenci
es for propagating cracks to remain straight or curve are explored as a con
sequence of crack interaction. The existence of spiral paths is demonstrate
d. (C) 2000 Elsevier Science Ltd. All rights reserved.