The Spine of the BioRID 2 model is fully pre-stressed. In the delivery position the bumpers and the muscle substitute springs are fully pre-stressed. The thoracic and lumbar spine are in a stress free position.
Pre-stressed components of the neck
The figure above shows the pre-stressed components of the neck. The neck is adjusted as prescribed in the ”BioRID II User’s Guide Denton ATD,Inc., 2002”. The delivery position of the thoracic and lumbar spine is stress free. The pre-stresses are generated
as follows:
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The initial stress in the bumpers is prescribed by use of the keyword *INITIAL_FOAM_REFERENCE_GEOMETRY.
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The muscle substitute springs are pre-stressed by an offset in the load curves.
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The torsional beams of the thoracic and lumbar spine are automatically pre-stressed after a positioning simulation. This is done by the use of relative rotation of the coordinate systems, which are referenced in the joint stiffness cards.