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...

Exact Stability Calculation for Timber Beams and Columns

A derivation is given of simplified, exact stability design rules according to limit analysis, applied to timber beam-columns. These rules are lacking but are necessary to be able to provide real and calculable reliability as is required according to European pacts and laws. Necessary therefore are the obtained exact combined bi-axial bending,...

Derivation of the Bi-axial Bending, Compression and Shear Strengths of Timber Beams

The derivation is given of the combined bi-axial bending, compression and shear strength of timber beams. As for other materials the elastic–full plastic limit design approach applies, which is known to precisely explain and predict uniaxial bending strength behaviour. The derivation is based on choosing the location of the neutral line. This...

Fracture Mechanics of Wood and Wood-Like Reinforced Polymers

This chapter discusses the theory of fracture mechanics based on the flat elliptical crack; the derivation of the mixed "mode I - II" - interaction equation, with the relations between the mode I and mode II stress intensities and energy release rates, based on an orthotropic-isotropic transformation of the Airy stress function; the derivation...