Designing Safer Car Seats for Children
The worst situation any parent could imagine is the loss of one’s child. Every year in Europe alone, 400 children die as a result of motor vehicle accidents and another 2,800 suffer serious injuries causing permanent disability.
The forces at play in these accidents can be enormous and quite often the resulting injuries sustained by children are greater than those sustained by the adults.
So how can crash forces on children be reduced and safety increased?
By tackling this question, the people at Malaika are designing the world’s first range of child car seats that will surpass every international safety standard – effectively raising the bar for child safety.
To meet such a challenge, the engineers at Malaika have implemented rigorous product testing and design verification procedures at both the component and system level.
FEA Analysis to Test Car Seat’s Components
The SimScale platform has been a requisite part of this process and a series of component simulations has validated the structural integrity of the primary ISOfix connection to the main chassis and the adjustment rack. Finite Element Analysis tests were conducted based on worst case scenarios to a force of 3600 N .
The primary ISOfix Connector is a steel component that attaches the adjustment bar on the base of the car seat to a fixed anchorage point in the vehicle’s body. In a vehicle crash, it is a critical component for ensuring that the car seat remains in place. The impact force is applied to the 4 bolts at the base of the connector. There is a sliding contact between the adjustment bar (which is fixed) and the circular connector head.
A second rim has been added to the circular connector head to increase the rigidity and strength of the part. High-stress zones are present on the circular connector head and near bolt holes.
The greatest displacements are seen at the base of the connector where the forces are applied. These are very small, however, and do not introduce design concerns.
Optimized and Safer Car Seat
The length adjustment rack is part of the base of the car seat and consists of a set of grooves into which steel teeth from the adjustment bar fit.
Sliding occurs between the grooves and teeth when a force is applied. There are significant stresses at the locations of contact under the worst case loading conditions.
Under these simulation conditions, the highest stresses occurred at the middle tooth.
These stresses exceed the tensile strength of steel signifying that material yielding is occurring. Locating these zones of yielding provides information as to where additional design considerations should be made before physical testing is done.
Having launched its car seat, the Malaika team planned to continue using structural simulations with SimScale to frequently test the designs and reduce the number of required physical prototypes. As a complement to physical testing, the SimScale platform completes the design cycle.