Abstract
An existing FEM program for elastic-plastic problems was modified to the one which can be accommodated to the changing of stiffness matrix and the release of stresses at fractured elements. With this program, the fracturing processes of two different mechanical tests of wood were simulated: the JIS shearing test (JIS Z2114) and the JIS bending test (JIS Z2113). The results are summarized as follows:
(1) The shearing strength obtained by the calculation was 8.6MPa. This value agreed with the actual testing data. The fracture initiated and propagated along the grains. This simulated result accorded well with the real fracturing process of the shearing test.
(2) The bending strength obtained by the calculation was 127MPa, which was larger than the actual value because the finite element mesh was rough and thus the scale factors for yielding had been estimated larger. The fracture initiated at the bottom of the specimen, grew to the neutral axis and turned its direction to the grain. This simulated result accorded well with the real fracturing process of the bending test.
