New Ford Fiesta Engineered for Safety, Economy and Style
- More than 55 percent of the body structure features high-strength and ultra-high-strength steel, ensuring occupant safety
- Lightweight body structure boosts fuel economy and lowers CO2 emissions
- All 2011 Fiesta models are equipped with a driver-side airbag. Trend and Sport models include a passenger-side airbag as standard equipment
- Under the stylish exterior of the new Ford Fiesta is a powerful body structure that can protect occupants in the event of a collision. More than 55 percent of the body structure is high-strength steel, including dual-phase steel and ultra-high-strength aluminised Boron steel.
ATHENS, OH – The 2011 Ford Fiesta’s shape is designed to provide added protection: the car is both rigid and stiff torsionally, surrounding occupants with a secure, safe cabin.
Although its body structure has been beefed up, Fiesta is still lightweight. Safety improvements have not compromised fuel economy or efforts to limit CO2 emissions.
“Safety is a very important attribute for the new Fiesta, but achieving real weight reduction was another key objective,” said Bernd Liesenfelder, body engineering manager for Fiesta. “High-strength steels, both cold- and hot-formed, were the key to delivering the light weight and high strength we need for structural efficiency. The material we use on Fiesta set new benchmarks in the small car segment.”
Structural strength for safety
Ford’s safety strategy employs high-strength steels to reinforce areas of the vehicle that are essential for crash protection. These include the floor structure, front rails and beams, and an ultra-rigid, integrated bodyside reinforcement ring to protect against side impact.
High-strength materials are used to create a stiff B-pillar section and a stiff rocker section fore and aft. This disperses the force of a side impact collision laterally to the opposite side of the car via chassis cross members. The integrated bodyside reinforcement ring also helps dissipate the force of front and rear impacts, and resists intrusion in case of a side impact.
“Safety performance is about more than just counting airbags,” said Joerg Beyer, chief carline engineer for the Fiesta. “At Ford, creating a very strong body structure to protect occupants comes first. With a robust structure, we can optimise our Intelligent Protection System to provide a tailored, protective cabin.”
Crash performance was evaluated using advanced computer simulation technology before real crash tests took place. “Simulation allows us to determine where performance issues may need to be addressed in the development stage, not in prototype,” Beyer added.
These high-strength elements are manufactured into an integrated sub assembly before they are joined to the vehicle in the body shop of the production line. This new process ensures better joint strength and greater precision.
“We discovered the benefits of the door rings when conducting front and side impact tests,” Liesenfelder said. “The ring structure helps us ensure minimal damage to the door openings in crash testing and is proof of the integrity of the safety cell.”
Even more high-strength steel
More high-strength steel can be found in other parts of the Fiesta’s body structure. Dual-phase steel front frame rails and side rails feature structural actuation points – called trigger points – to initiate predictable collapse in crush zones. By forming the “triggers”, this hardens the dual-phase material giving it the unique ability to both absorb and resist the force of an impact.
“The front of the rail is a crush zone but to avoid overloading the backup structures, the rail is designed to bend and counter-bend while still offering very stiff resistance against further intrusion,” Liesenfelder explained. “We call this a ‘crush-bend-bend-bend’ strategy.”
Fiesta’s underfloor structural beams – so-called ‘sled runners’ – also are formed from dual-phase steel as are lateral reinforcements that are designed to manage side impact force
To help support the use of high strength steels, advanced manufacturing techniques were employed, including the use of new robotic welding heads.
Intelligent Protection System
As part of Ford’s Intelligent Protection System (IPS), all Fiesta models are equipped with a driver-side airbag. Trend and Sport models include a passenger-side airbag as standard equipment.
Part of Ford’s IPS technology includes extensive airbag sensor calibration testing. Engineers worked to ensure that the airbags are activated quickly and deployed in appropriate circumstances.
Three-point safety belts with dual-stage digressive load-limiting pre-tensioners are standard for both front seat occupants. In the rear, three-point safety belts are provided for the two outboard passengers. The retractors pull the safety belt tightly to position the occupant ideally for airbag effectiveness. Dual-stage digressive load limiting features allow for a slight reduction in belt tension to reduce the possibility of a chest injury in the event of a crash.
Adjustable head rests optimise whiplash protection and front seats feature an anti-submarine design.
For additional driver safety, a special carpet underlay called a crash pad is placed between the floor panel and carpet to minimise impact to the lower leg during a crash. A safety belt reminder system is standard and reminds the driver to buckle up before driving.
“Many once said it was important to drive a big, heavy car because of safety. The new Ford Fiesta is a great example of using smart engineering to increase safety, gas mileage and design options,” said Jeff Wood, President of Don Wood Ford, Athens, Ohio.
[FORD]
