The Myth of Softening behavior of the Cohesive Zone Model Exact derivation of yield drop behavior of wood

It is shown that the postulate of strain softening of the fracture stress is based on the error to regard the nominal stress to be the actual, ultimate stress, at the actual area of the fracture plan. Strain sof-tening called yield drop is elastic unloading of the actual elastic stress at the intact, not ltimate, elas-tic loaded part of the...

Limit analysis discussion of design methods for fracture of timber dowel joints loaded perpendicular to grain

The results of an investigation of splitting of joints of [1] are used for a discussion of design methods and as necessary answer on comments and for confirmation of the extended fracture mechanics theory which accounts for the part of the external energy which is needed for plastic dissipation at the dowels, (which cause the crack opening). It...

Exact derivation of the geometric correction factor of the center notched test specimen, based on small cracks merging as explanation of softening

The exact derivation of the mode I geometric correction factor is given, based on the small crack merging mechanism to show that this always is the real fracture mechanism in wood. This mechanism dominates at late softening and explains fully the apparent decrease of the energy release rate of macrocrack extension as already known for mode I and...