Crashworthiness:
Glazing & Roof Crush

 

Dr. Stephen A. Batzer is the Engineering Institute’s principal failure analyst. He has particular expertise with respect to automobiles, buses and trucks, but also examines firearms and industrial equipment. He has published numerous peer-reviewed articles on automotive crashworthiness, and is a regular invited speaker on this topic at universities and at other forums.

 

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Occupant Retention Side Glass

Ejection through automotive side windows is a serious public health concern that can be effectively addressed through proper system design.

Currently, the majority of passenger vehicles have relatively weak roofs. These roofs induce fracture of the tempered side windows and open a portal for partial or total ejection during rollover collisions and side impacts; if the window is large and not covered by a side curtain airbag. Field experience has shown that even properly belted occupants can be partially or fully ejected through such side windows and sunroofs during collisions and suffer serious injury or death.

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Automotive Roof Crush

“The crush resistance of roof structures is critical to minimizing injuries and enhancing occupant survival during rollover crashes.”
[Baccouche, 2000]

All reasonable engineers agree that stronger roofs maintaining the occupant’s survival space are safer roofs during rollover. Dr. Batzer is The Engineering Institute’s crashworthiness expert. He is a leader in the national dialogue on this aspect of rollover safety.  A typical roof involved in a rollover which produces a life-altering injury has a strength-to-weight ratio of 2. A roof designed to protect its occupants crush space during a multiple-turnover collision has a strength-to-weight ratio of 3.5 or higher, as is shown by these Volvo vehicles pictured.

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Heavy Truck Rollover

 

Installation of a roll cage within these heavy trucks is a technically feasible, cost-effective solution to the clear danger inherent in under-designed trucks.

National accident statistics consistently show that the profession of Class VIII truck drivers is dangerous, and that their fatality rate is very high.

One significant reason for this is the lack of rollover crashworthiness of many commercial truck designs.

Analysis of numerous trucks that have been through rollovers shows the cabs are typically designed to be durable, rather than strong, energy absorbing, and able to maintain shape under significant loading.

 

 

 

 

 

 

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Motorcoach Bus Rollover

Occupant safety in motor coaches/buses is dramatically reduced due to the typical absence of a passive restraint system to prevent occupant motion in frontal, side, or rollover collisions. According to the National Transportation Safety Bureau Special Investigative Report NTSB/SIR-99/04 report, the principal cause of motor coach/bus fatalities is ejection. Ejection occurrence can be reduced by utilizing available seat belts, as well as incorporating advanced side glazing to retain the occupants within the cabin throughout the crash event.