A hollow shaft is made by rolling a metal plate of thickness t into a cylindrical form a...

A hollow shaft is made by rolling a metal plate of thickness t into a cylindrical form and welding the edges along the helical seams oriented at an angle of φ to the axis of the member (Fig. P6.8). Calculate the maximum torque that can be applied to the shaft. Assumption: The allowable tensile and shear stresses in the weld are 120 MPa and 50 MPa, respectively. Given: D = 100 mm, t = 5 mm, and φ = 50°.