Computer Aided Engineering (CAE) FEA Case Study: Results Tensile Stress
Maximum principal stresses - tensile stress 
Tensile Stress: Part of the model has disappeared (inside inner rim circumference), due to the colour bar being set to show positive (0-100MPa) numbers and those stresses are negative or compressive. Therefore, the inner rim, outside lower spokes and the inside upper spokes are in tensile stress. Tensile stresses are of most concern since they do the damage for fatigue and damage tolerance, and are usually higher than the Von Mises stress prediction. The difference between Von Mises and maximum principal stress has to be carefully evaluated.
Displacement Result: Displacement does not change. The 100mm displacement of the wheel alone, against 210mm of the tyre plus the wheel means that the tyre is deflecting 110mm under load. A closer inspection of the displacement in the tensile stressed spokes and rim will aid undertanding of the stresses since in a linear statics analysis, the displacement (strain) is directionally proportional (via Young's Modulus and Poisson's Ratio) to stress.