In the design of an automobile, a most important task is to
minimize the occurrence of automobile accidents. Automotive safety can be
improved by ‘active’ as well as ‘passive’ measures. Active safety refers to
technology which assists in the prevention of a crash. Passive safety includes
all components of the vehicle that help to reduce the aggressiveness of the
crash event. Crash protection priorities vary with the speed of the car when
crash occurs 7:
at speeds up to 15 km/h, the
main goal is to minimize repair costs.
at speeds between 15 and 40
km/h, the first aim is to protect pedestrians.
at speeds over 40 km/h, the
most important concern is to guarantee occupant protection.
In the early 1950s
the term ‘crashworthiness’ was first used in the aviation industry. It provides
a measure of the ability of a structure to protect the occupants in any
survivable crashes. Similarly, in the automotive industry crashworthiness is an
ability of the structure or any of its components to protect a passenger of a
vehicle by absorbing the energy of an impact in the event of crash 9. Vehicle
crashworthiness and passenger safety are the most important and challenging
design considerations. There has been a huge evolution in the goals and requirements
of crashworthiness over the past years. Current vehicles have bodies
manufactured using stamped steel panels and are assembled using various
techniques. Designers create vehicle structures basically to provide occupant
safety by controlling the crash deceleration pulse to fall below human
survivable levels. So, the goal of crashworthiness is to optimize the vehicle
structure such that it can absorb significant crash energy by controlling
deformations. While maintaining enough space in occupant compartment so that
residual energy and magnitude of loads transferred to the occupants can be
minimize. Considering real time scenarios there could be different events of
vehicle collisions, both vehicles may be of similar or different types, sizes,
or shapes. It could also be with a stationary object such as a tree, building, bridge,
or utility pole.