RCID

Seat Frame

Problem

The RCID was approached by a manufacturer of low volume, custom vehicles. They had physically tested one of their forward facing twin seat frames and found that it badly failed to meet the required crash safety standards. The RCID was asked to analyse the design to identify problem areas and to design a new frame capable of withstanding the specified crash loadings.

Original frame

A detailed 3D model of the original seat frame was created in Pro/Engineer. This was used to create a shell element model in Pro/Mechanica. The crash loads produced in the seatbelts were applied to the model and the results matched the practical test findings. The predicted failure mechanism matched that found in the tests.

New Frame

The RCID was given a specification around which they designed a new seat frame. The frame was to be fabricated from simple steel sections and plate, welded together. The mounting of the frame onto the floor could only occur along its centreline.

Finite Element Analysis was used to optimise the positioning and size of the sections. The analyses showed where material could be removed and where reinforcements were required.

The RCID produced manufacturing drawings for the new seat frame.

Testing

The original 20kg frame had suffered total collapse as it was generally too weak. The new frame was only 5kg heavier but passed its third party physical test first time and was certified as suitable for use in a passenger vehicle.

Further Work

Following this work the client asked the RCID to redesign a rear facing seat and the subframe used to mount the seat frame onto the vehicle chassis.