Modelling of human body parts for analysis of occupant loads in traffic accidents

The proposed project focuses on the modelling of anatomical human structures which affect motion and loads, especially those of the neck under vehicle collision conditions. The most essential project assignments include measurements of mechanical properties of neck ligaments; development of a detailed FEM model (Finite Element) of the neck; performance of sled tests for the purpose of validation of the FEM model of the neck; integration of the FEM model of the neck with the existing rigid-body dynamics model of the human body. Tension tests of the cervical spine soft tissues will be performed. The main goal of these tests is to determine the parameters of material properties of soft tissues based on the measured stress-strain curve: initial non-linear characteristics, elasticity module, failure parameters and viscoelastic properties of soft tissues. Furthermore the impact of the strain velocity and age of the donor on the behaviour of anatomical structures will be analysed. The tests will be performed on a purpose-built test rig and under physiological conditions. Individual groups of test samples will enable statistical evaluation of the obtained results. The determined biomechanical properties of the samples will be included in a FEM model of the neck. The neck model which includes the upper thorax and head should enable the scaling of the tissue geometry and material properties, which shall further enable model adaptation to specific properties of anatomical structures such as the body constitution, age and gender. For the verification of the FEM model of the neck, sled tests will be performed on a sled test device. Sled tests will be performed for representative types of body constitution with direction and impact intensity variations. Furthermore coupled simulations of the FEM model of the neck and RBD (Rigid Body Dynamics) model of the human body will be determined, which will improve the quality of the analysis of the dynamic response of a vehicle occupant under impact conditions.

It is estimated that 90 million people around the world currently suffer from some form of spinal cord injury. In two-thirds of cases road accidents are the cause of injury with sporting accidents making up another 10% of the total. The cervical spine is a complex anatomical region. Its primary function is to provide head support and mobility as well as protection of the spinal cord. In traffic accidents the cervical spine is often injured, especially at low speed of the vehicle impact (whiplash injury). These injuries are mostly light (AIS 1-2 severity). However, they may cause long-term consequences such as neck pain, headache, decreased mobility of the head and neck. In order to understand the mechanism of injury and injury quantification, the human neck model must provide a reliable simulation of the head movement in relation to the thorax as well as simulation of loads and stresses in the cervical spine structures. The quality of the FEM (Finite Element) Model and simulation results is subject of the accuracy of geometrical and mass properties as well as material properties of anatomical structures the model takes account of. The project focused on the modelling of anatomical human structures which affect motion and loads, especially those of the neck under vehicle collision conditions. The most essential project assignments included measurements of mechanical properties of neck ligaments; development of a detailed FEM model of the neck; performance of sled tests for the purpose of validation of the FEM model of the neck; integration of the FEM model of the neck with the existing rigid-body dynamics model of the human body. Tension tests of the cervical spine soft tissues were performed. The main goal of these tests was to determine the parameters of material properties of soft tissues based on the measured stress-strain curve: initial non-linear characteristics, elasticity module, failure parameters and viscoelastic properties of soft tissues. Furthermore the impact of the strain velocity and age of the donor on the behaviour of anatomical structures was analysed. The tests were performed on a purpose-built test rig and under physiological conditions. Individual groups of test samples enabled statistical evaluation of the obtained results. The determined biomechanical properties of the samples was included in a FEM model of the neck. The neck model which includes the upper thorax and head should enabled the scaling of the tissue geometry and material properties, which shall further enable model adaptation to specific properties of anatomical structures such as the body constitution, age and gender. For the verification of the FEM model of the neck, sled tests was performed on a sled test device. Sled tests was performed for representative types of body constitution with direction and impact intensity variations. Furthermore coupled simulations of the FEM model of the neck and RBD (Rigid Body Dynamics) model of the human body was determined, which improved the quality of the analysis of the dynamic response of a vehicle occupant under impact conditions.