Case study: Seat frames for the Future Steel Vehicle

How Tata reduced weight by 30%

The WorldAutoSteel ‘Future Steel Vehicle’ is an ultra-lightweight body structure concept for future electric and hybrid vehicles with a 35% weight reduction compared with the project baseline vehicle and 23% compared with current production small cars. Tata Steel, part of the Future Steel Vehicle project, has performed optimisation studies for application of its advanced steels.

The Future Steel Vehicle team developed a basic front seat frame which allowed side impact load to be transmitted to improve side impact occupant protection but no design or gauge and grade optimisation of the seat was undertaken during the project. Tata Steel developed the basic Future Steel Vehicle front seat design, optimised steel grades and gauges, and compared cost and weight against the baseline Future Steel Vehicle seat frame design for equivalent performance.

Modelling

Tata Steel developed the basic Future Steel Vehicle front seat using Catia to design the seat track, cushion sidemember, seat base, tubular seat crossmembers, seatback sidemember and headrest support. The seat geometry and structure was developed to use the latest thinking in steels, forming and joining processes in seat manufacture, and paid particular attention to achieve the same side impact performance as the Future Steel Vehicle seat.

Upon completion of the seat design model, Tata Steel generated a CAE model using Hypermesh to fully represent the front seat structure, seat and backrest foam cushions and a belted occupant on the seat.

Analysis

Dynamic finite element analysis using LS Dyna was used to calculate seat deformation and the strains and stresses resulting from both forward and rearward crash tests to meet requirements of European regulation ECE R17.

Front seat frame structural performance – particularly to meet stiffness and occupant safety requirements – was then optimised using advanced CAE simulation techniques to develop the application of the latest Tata Steel advanced high strength steels. These accounted for up to half of the material used to make the seat frame and track.

tags: Lightweighting Safety
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