Toyota Prius Uses High Strength Steel for Safety-Critical Structure
Toyota’s Prius, the most successful hybrid on the market today, is hitting the road with a second generation that has steel at the center of its environmentally efficient design. Just named to Car and Driver’s “10 Best” list mere days after the hybrid was named Motor Trend’s “Car of the Year, Prius uses high strength steel to manufacture certain safety-critical structural features.
Prius was designed to meet the world’s toughest crash safety standards. It has a strong body, with a reinforced cabin, dual SRS airbag installation and force-limiting front seatbelt pretensioners. Prius has passed a 40 percent offset deformable barrier test at an impact speed of 64km/h and has also met the European dynamic side impact test at 55km/h. It has been tested for full-frontal collision barrier at 55km/h, roll over and rear moving barrier.
GOA Safety Body:
Prius’ safety cage was developed using Toyota’s Global Outstanding Assessment (or GOA) process. In the GOA process, Toyota reviews current and anticipated safety standards and designs the vehicle to exceed those standards. Toyota also has its own strict in-house standards. Prius has been tested to new European standards, and Japanese and US requirements, as well as Toyota’s strict in-house goal of having the highest passive safety in its class.
The body has crumple zones front and rear, and a high-integrity cabin section. The crumple zones are designed to progressively absorb impact energy. The cabin is designed to provide survival space for the occupants, including head and foot space. Prius’ new side impact collision protection measures include optimum placement of side impact beams and belt-line reinforcements. New passive safety features in second-generation Prius include:
- a reinforced front bumper
- varying metal thickness joining the front side members, to control deformation of the members during impact
- design features to disperse impact collision energy via under floor reinforcement, floor tunnel reinforcement and rocker reinforcements
- strengthened cowl side and door belt lines, to disperse impact energy and minimize cabin deformation new tibia pads on the cabin front foot wells, to minimize injury to the lower body in the event of a collision.
High-strength steels played an integral role in the development of this GOA approved safety cage. High-strength steel and hot-stamp methods have been used to optimize the centre pillar reinforcement. The new Prius body makes extensive use of super high-strength steel in the centre pillar and high strength steel sheet in many areas. All the major longitudinal members in the vehicle, as well as the door skins, the entire front door surround and the majority of the rear door surround are pressed from hot stamp, high-strength steel or super high-strength steel sheet.
