Question 2

A local composite manufacturer uses filament winding to manufacture carbon fibre reinforced polymer (CFRP) tubes for rocket structures. To test the tubes, a CFRP tube is clamped between two rigid end plates and secured by four M8 bolts that are symmetrically spaced at each corner of the end plate, as shown in the sectioned, cut away view below.

For a CFRP tube with outer diameter 47 mm and wall thickness 4.1 mm, if the nuts are turned 0.5 turns to clamp the tube

2.1 Calculate the axial stress in each bolt.

Give your answer to 3 significant figures