Fig. 11.

Strain vector plots of strain data collected from the intra-orbital surfaces of the supraorbital torus. The top figure shows 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 figure illustrates in silico data from corresponding ‘gage sites’ on the model. For the in silico data, 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 in vivo strain vectors for experiments 47 and 13 are shown in the bottom two figures. The black arrows on the in vivo plots represent the extremes of the ranges of the mean ε₁ orientations from the in silico‘gage sites’. In vivo strain orientations are presented in Table 4 as angles relative to the plane of the orbital aperture. The strain vectors for the intraorbital sites are viewed through the supraorbital torus. To illustrate their orientation, the strain vectors were reflected about the A-element of the strain gage. In addition, it should be noted that the strain data for the working side shown in the skull's left orbit were actually recorded from within the right orbit: they are illustrated on the left side after reflecting them about the mid-sagittal plane.