I´m really struggling to find the shear force here. 1. The problem statement, all variables and given/known data Hight h of a specimen = 100mm and diameter is 54mm. Max force F=144,6 N and deformation is δ=5mm 2. Relevant equations I have to find ε=δ/h Area of specimen before deformation=54mm*100mm=5400mm σz =(F(1-ε))/A Shear force = σz /2 3. The attempt at a solution ε=δ/h=5/100=0.05 A=5400mm σz =(F(1-ε))/A=(144,6(1-0.05))/5400=0,025N/mm2 Shear Force=0,025/2=0,0127N/mm2 which gives 12,7kN/m2. The right answer is 30kN/m2. Any thoughts?