The simply supported timber beam of Figure 1 is made-up by gluing together three 300 mm by 150 mm planks as shown. The beam has to carry a uniformly distributed vertically downward load of 8 kN/m for the whole length. The span of the beam is L m. 1 (a) If the maximum flexural stress to maximum shear stress ratio in the beam is limited to 15, determine the maximum allowable span of the beam. (7 marks) 1(b) Determine the maximum shear stress in wood for using the maximum allowable span. (3 marks) 1 (c) Determine the minimum shear strength of the glue required for using the maximum allowable span of the beam. (3 marks) 1(d) Sketch the shear stress and flexural stress distributions in the cross-section for using the maximum allowable span. 8 kN/m Glue Lm FIGURE 1 Page 1 of 5 (2 marks) 150 mm 150 mm 150 mm 300 mm + +