Fig. 7.

Strain orientations on the anterior surface of the postorbital bar on the right (balancing) and left (working) sides of the FEM of the macaque cranium. Each line is a vector representing the mean orientation and magnitude of maximum (ε₁) (red to yellow) and minimum (ε₂) (blue to green) principal strains from all the elements at the gage site. Note that the variance among the vectors from the in silico gage sites is due to variation in bite point, and the variance among vectors from in vivo gage sites is due to variation in magnitude and location of bite force, joint reaction forces and muscle forces. The top figures show the strain field of maximum principal strain orientations at the centroid of each element. Note that the strain field vectors values were not transformed into the coordinate system of the model surface, which the strain gages sample, whereas the bite point means were appropriately transformed. The second row of figures shows the orientations of the mean tensile and compressive in silico strain vectors at the lower gage site. The third row of figures shows the orientations of the mean tensile and compressive in silico strain vectors at the upper gage site. The ranges of the maximum (ε₁) principal strains in silico were transferred to Fig. 6 for comparison with the in vivo strain vectors using the reference line indicated.