Human Body Models: BOSS-Models - Preventive Biomechanics - page 240

slide and roll motion. A friction coefficient of 0.01 was assumed between the car-
tilage layers. Since the inter-cuneiform joints only permit minor movement, they
were assumed to be elastic and modelled as a continuum. Relative motion of the
interconnected bones of the metatarsus (os cuboideum, os cuneiforme) and ossa
metatarsi (tarsometatarsal joint) as well as ossa metatarsi and toes (basic joints) was
modelled via hinge joints. Kinematic modelling of the bone connections was done
analogue to the vertebrae, using defined stop functions to limit relative motion.
Toe modelling was simplified by assuming the phalanx row (cf. Fig. 5.74 )asa
continuous segment. The joint connections between the phalanx bones were thus
neglected. Besides the nine phalanx joints, 22 of the total 31 foot joints were modelled.
5.3.7 B OSS -Model for Crash (Upper Body)
To increase passenger safety in automobile crash scenarios, as well provide enhanced
pedestrian protection, the automobile industry, the German ADAC association and
other organizations have conducted crash tests employing crash test dummies made of
technical materials. Besides expensive dummy test devices, fully equipped automo-
biles are tested, both of which involve considerable cost. Progress in computer
technology, together with simulation software have made crash simulations a well-
established approach in car manufacturing. To date, crash simulations involve digital
copies of real physical dummies. Recently, however, approaches have included digital
human body models, allowing realistic simulation of the entire human body, including
the skeleton, muscles, soft tissues, organs and vessels.
With the help of these human body models, virtual crash scenarios can be
simulated and more realistic conclusions can be reached regarding risk of pas-
senger injury. However, such models have not yet received common acceptance,
since they require further refinement.
A simulation model for high-speed scenarios, based on anatomical data of the
BoMo4 model (cf. Table 5.10 in Sect. 5.3.4 ) as well as BoMo 6 (cf. Table 5.13 in
Sect. 5.3.5 ) and material data derived at equivalent high strain rates for bone,
tissue etc. is presented. The B OSS -Procedure (as described in Chap. 2 ) is employed
with appropriate testing equipment.
Figure 5.75 exemplarily illustrates a single step in the finite element model
generation process using the example of the kidneys. Figure 5.76 shows different
views of skeletal structures, mainly of the thorax region, and Fig. 5.77 includes inner
organs such as the heart, aorta, vena cava as well as liver, spleen and kidneys.
Figure 5.78 shows the model as depicted in Fig. 5.77 , including the lungs, Figs. 5.79
and 5.80 depict the muscle groups and the adipose tissue with skin, and Fig. 5.81
provides an overview, showing the outer skin surface with organs and skeleton.