This preview shows page 1. Sign up to view the full content.
Unformatted text preview: ifferent part geometries, the actual measured inspection data can be used. However, often the number of observations is not sufficient when variance is simulated. Instead, one can generate random part geometry Ms with maintained correlation by using equation 2. C (i, j ) R(i, j ) = , where C = cov (M) (1) C (i, i )C ( j , j ) M s = cov(M ) ⋅ N (0,1) + M (2) N(0,1) is random generated numbers with mean of zero and a standard deviation of one and M is the mean of the inspection points. In this simulation equation 2 is used to generate correlated part geometry. Practical Implications in Tolerance Analysis 315 Figure 1: Assembly model
3.2. Simulation model FEA is used to produce part variation by applying a displacement corresponding to the inspection data in the nodes closest to the inspection point. The parts are joined together by applying an equal magnitude of force in the spot welds. After a spot weld has been joined, a rigid beam is activated in the weld to prevent the weld to open during the rest of the simulation. When the welding is complete,...
View Full Document
- Spring '10
- The Land