The strength of glulam beams with holes - A survey of tests and calculation methods

A compilation of available test results relating to the strength of
glulam beams with holes is presented. A total of 182 individual
tests from 8 different sources are described concerning material,
test setup and recorded crack loads and failure loads. A brief
description of some available methods for strength analysis of
timber is given and specific calculation approaches for the strength
of glulam beams with holes are compiled. Design rules according to
some European codes are reviewed and compared to experimental test
results. Fundamentally different design approaches are found among
the reviewed codes and the comparison reveals significant
discrepancies between the predicted strengths according to the
different codes.