PROPOSAL OF DESIGN STRENGTH FOR GLUE-LAMINATED TIMBER BEAMS WITH A CIRCULAR THROUGH-HOLE

The purpose of this study is to evaluate strength of glue-laminated timber beams with a circular through-hole. Pure bending tests and bending shear tests of glue-laminated timber beams with a hole were performed. The parameters of the tests were the diameter of the hole for the depth of beam. The results of these tests and finite element analyses established the evaluation method of glue-laminated timber beams with a hole. In pure bending tests, the bending strength of the beam was evaluated with section modulus and the tensile strength of the bottom range lamina in consideration of knots. In bending shear test, the bending shear strength of the beam was evaluated using the tangential stress of the hole and the tensile strength for the fiber angle of the wood. M-Q interaction curves of the beam with the hole using these evaluation methods were proposed.