The elastic support method was recently developed to simulate the effects o
f unbounded solids in the finite element analysis of stresses and displacem
ents. The method eliminates all the computational disadvantages encountered
in the use of 'infinite' elements or coupled finite element boundary eleme
nt methods while retaining all the computational advantages of the finite e
lement method. In this paper, the method is extended to the elasto-plastic
analysis of fracture in infinite solids by using the load increment approac
h and including the effects of strain hardening. Numerical tests and parame
tric study are conducted by analysing a straight crack in an infinite plate
. Present results for J integrals and plastified zones are compared, respec
tively, with analytical solutions and available results obtained by using t
he body force method. The agreement between the results is found to be very
good even if the truncation boundary of the finite element model is locate
d very close to the crack tip or the plastified zone.