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Positioning File

If the upper legs are rotated at the hip joints, initial penetrations would occur. This reaction is based on the hardware. In the hardware, the geometry is deformed if the position of the upper leg is changed with respect to the pelvis. It is better to position the upper legs by a pre-simulation. A special positioning-file <positioning_BioRID-2_v4.0.1_mm_ms_kg.key> is delivered to do this pre-simulation. This file can also be used to move and rotate the head relative to the T1 vertebrae. 

The positioning file of BioRID2 is very easy to use. At the top of this file you will find a set of parameters to be defined. These parameters are shown in the following table.

 

Parameter Description
term termination time
tmove time to move parts
trans_x translation of whole dummy model in x direction
trans_z translation of whole dummy model in z direction
movhead global x translation head
rothead local y rotation head
relhead release time for head boundaries
lfemrx left femur rotation about local x
rfemrx right femur rotation about local x
lfemry left femur rotation about local y
rfemry right femur rotation about local y
lfemrz left femur rotation about local z
rfemrz right femur rotation about local z

 

If you do not want to translate or rotate an assembly use a very small value like 1.0E-20. Please do not use zero as the value, because zero as scaling factor is default 1 in LS-DYNA . As the second step you have to fill in your include files necessary for positioning the dummy model. Usually only the seat model and the dummy model are used for the positioning procedure. Please define a *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE for contact between dummy and the seat (environment). The BioRID-2 properties for this contact are defined in the part set 1500.

Since BioRID version 3.8 this file can also be used to adjust the Head position with respect to the T1 vertebrae. In principle this can also be done during a pre-simulation where other limbs are moved. To setup this simulation a value for the Parameter movhead must be specified. This value should not exceed the values where the Head will remain in position due to the cable friction. It higher values are chosen, the Head will not remain in position at the beginning of Whiplash simulation.