Anti-intrusion bar
An anti-intrusion bar or beam is a
Designs to counteract side impact collisions were explored as early as 1969 by General Motors,[2] and Ford was issued a patent for the technology in 1975.[3] Volvo introduced the Side Impact Protection System for its 700, 800, and 900[4] series cars in the early 1990s.[5]
Performance
The performance of a side beam is measured by several indicators. The most important are:
- the Specific Energy Absorption (SEA), which measures the amount of energy absorbed per unit mass;
- and the energy efficiency η, which is the ratio between the mean load and the peak load transmitted to the vehicle during the impact.
Furthermore:
- the amount of intrusion, for a given energy, must be as small as possible;
- the maximum depth or diameter of the bar must be reasonably small, as the vehicle door does not generally allow much space;
- the cost of the member must be reasonably small.
Typical design
The anti-intrusion beams commonly span the length of the door at about a vertical midsection of the door. As the figure shows, the typical profiles can be open or closed (tubular, usually with a round cross section).
They are conventionally made by stamping or hydroforming processes. When the cross section is closed, the tubes can be used as-received. In the scientific and technical literature, some unconventional designs have been proposed.[6]
Typical materials
The anti-intrusion bars are generally made of high strength steels.[7] However, some studies indicate that stainless steel 304 might be a better choice, because of its larger plastic field and a larger amount of potentially absorbed energy before fracture.[8] In the scientific and technical literature, some unconventional material combinations have been proposed, too, e.g. based on metal foam filled tubes[9] or composite materials.[10]
See also
References
- ^ "On the Safe Side" (PDF). Crash Test Technology International. May 2009.
- doi:10.4271/690003.
- ^ Ford Motor Company. "Side door intrusion protection (US3868796A)". Google Patents.
- ^ "Volvo '92: New model, new engine and a unique safety innovation". new.volvocars.com (Press release). Rockleigh, New Jersey: Volvo Cars of North America. 1992. Archived from the original on 2017-02-06. Retrieved 2017-07-07.
- ^ "R&D milestones of the Volvo Group". www.volvogroup.com. Volvo Group. 2011. Archived from the original on 2011-06-16. Retrieved 2017-07-07.
- ^ "Vehicle anti intrusion bar by Bond, Sam – AU 1999065514".
- ^ High Strength Steel for Automotive Safety Components Archived December 20, 2011, at the Wayback Machine
- ^ Coppola, T.; Picella, P.; Segala, S.; Migliorini, R.; Capelli, F. "National Benchmark on Material Performance in Anti-Intrusion Beams" (PDF). Archived (PDF) from the original on June 29, 2023.
- S2CID 136670060.
- ^ "Anti-intrusion beam for vehicle door assembly - US Patent 7819462 Description". www.patentstorm.us. Archived from the original on 21 April 2013. Retrieved 6 June 2022.