1. The problem statement, all variables and given/known data I need to know the correct equations for a pinned-pinned beam and a fixed-fixed beam with 3 point loads(450N, 0.3 from the left,450 0.7 from left and 450 1.1 from the left, the beam is 1.4m long, with maximum deflection and bending stresses But I have to use the second moment of area for a hollow shaft(100mm diameter, 6mm thickness) which i have as 107.6.(I=pi(100^4-94^4/64) and a youngs modulus of 206e9 2. Relevant equations I am sure you have to work out each point load seperately and add them together. But at the moment i have, 3pa^3b^2/3EI(3a+b)^2 for a cantilever fixed at both ends. [b3. The attempt at a solution[/b] The answers I have for a cantilver fixed at both endsare 1.66x10^-13, 1.534x10-12 and 1.607x10-12, so adding them together i have 3.307x0-12 for deflection, not sure if this is right.