Redesigning and non-linear parametric and free-size optimization of an Mg alloy automotive seat frame

The application of Mg alloy parts in the automotive industry is increasing to reduce weight and fuel consumption. One of the high potential parts for the application of Mg alloys in the front seat frame. However, change of material is accompanied by a change of the manufacturing process and change of design for the seat frame. In the present research, while keeping the reference overall ergonomic outline, a new substitute Mg alloy design was proposed, featuring a simple and easy to manufacture Z profile. Next, a two-stage optimization technique (size and shape) is proposed for the Mg seat frame based on the stress and displacement criteria of standard test plans. The final optimized design is close to a fully-stressed state and is 70% lighter than the reference steel backrest. The low density of Mg compensates the effect of thickness increase on seat frame weight and material cost.