View Policies Current Attempt in Progress A glue-laminated timber beam is reinforced by carbon fiber reinforced plastic (CFRP) material bonded to its bottom surface. The cross section of the composite beam is shown. The elastic modulus of the wood is 12.1 GPa and the elastic modulus of the CFRP is 117 GPa. The simply supported beam spans 6.6 m and carries a concentrated load Pat midspan. Assume bw=61 mm, b=45 mm, dw=260 mm and t=5 mm. (a) Determine the maximum bending stresses o,, o, produced in the timber and the CFRP if P = 5.7 kN. (b) Assume that the allowable bending stresses of the timber and the CFRP are 10.8 MPa and 1400 MPa, respectively. Determine the largest acceptable magnitude for concentrated load P. (You may neglect the weight of the beam in your calculations.) dw B L CFRP Cross section Answers: (a) o, = i MPa, o, = i MPa. (b) P = i kN.

A composite sample of carbon reinforced epoxy has dimensions of in 20 in x 20 in x 0.135 in and mass of 3 lb. The carbon fibres have a modulus of elasticity of 80(106) lb/in2 and a density of 0.15 lb/in3. The epoxy matrix has modulus of elasticity of 0.90(106) lb/in2 and a density of 0.05 lb/in3.  Assume there are no voids in the sample, calculate the volume fraction of: (i) The carbon fibres (ii) The epoxy matrix in the sample.

A composite primary steel beam with a span of 8m supports a secondary beam at midspan, which applies an characteristic (unfactored) load of 239kN to the primary beam. What elastic modulus (in cm³) does the beam require to be able to carry the load if the allowable stress due to the characteristic loads is 210N/mm2? It may be assumed that the elastic modulus required for the composite beam is 63% of that required for the equivalent non-composite beam.

The composite shaft shown consists of a solid brass segment (1) and a solid aluminum segment (2) that are connected at flange B and securely attached to rigid walls at A and C. Brass segment (1) has a diameter of 18 mm, a length of L₁ 235 mm, and a shear modulus of 39 GPa. Aluminum segment (2) has a diameter of 24 mm, a length of L₂ = 165 mm, and a shear modulus of 28 GPa. If a concentrated torque of 270 N-m is applied to flange B, determine (a) the maximum shear stress magnitudes in segments (1) and (2). (b) the rotation angle of flange B relative to support A. N 235 mm (1) B 165 mm Partial Ans: Max shear stress in Member 1 is 55.7 MPa 270 N-m (2)