An automated belt fitting tool for 6 and 10 year-old child crash dummies

Modelling child occupant safety through computer aided engineering (CAE) within a vehicle is an area that is constantly developing. In 2003, Euro NCAP introduced a child occupant protection rating to inform consumers the results of vehicle safety assessments [1]. These assessments used 18 month and 3 year old dummies in frontal and side crash. Developments in technology and crash dummies have led to the introduction of new larger child dummies in the Q series, those being the 6 and 10 year old. In 2016-18 it is proposed these will be used in frontal and side EuroNCAP consumer crash ratings, where the dummy will be sat in a child seat. In the competitive market there is a demand on manufacturers to produce cars in a shorter time frame from idea to production, therefore making the overall process more efficient and cost effective. One area that this places emphasis on is predicting how cars perform where it has the potential to reduce the need to produce as many prototype vehicles. To ensure the results are accurate the predictive method of finite element analysis (FEA) is very dependent on the inputs, where those are primarily grouped into materials, geometry and boundary conditions. In terms of the child occupant prediction this means obtaining realistic inputs to gain realistic output kinematics and injury criteria during the frontal or side crash. The belt restraint system is one of the most predominant in affecting the child kinematics and one that needs to be modelled accurately. This paper will describe an automated seat belt fitting method using the LS- DYNA® package that is efficient and effective in creating a belt geometry and path for a 6 and 10 year old dummy in a child seat.