• XSENSOR Staff Writer

Measuring loads on crash test dummies during impact tests

Updated: Sep 2

It’s surprising, but even in 2019 many car makers still design with data based on crash test dummies the size of the average male. Which is why, based on real-world crash data collected since the 1970’s, Volvo recently discovered that women are at higher risk of whiplash in an accident, due to their obviously different anatomy from the “average male.” Because they’re generally shorter than men, women sit closer to the wheel and lower in the seat, meaning they’re also more likely to suffer chest injuries and require different head protection.

A University of Virginia study set to be published in an upcoming issue of the journal Traffic Injury Prevention looked at 22,854 frontal crashes between the years 1998 and 2015 involving 31,254 occupants, ranging in age from 13 to 97 years old, with a near equal proportion of males (49.4 per cent) and females (50.6 per cent). All were restrained by a three-point safety belt. Pregnant occupants past their first trimester were excluded.  Researchers found the odds of a female sustaining a serious to fatal injury in a collision are 73 per cent higher than they are for a male.

Regardless of gender, height, shape or weight, it seems obvious that cars must be designed with the aim to protect all people beyond the ‘average man’ represented by crash test dummies.  Differences in fat distribution, muscle strength, bony alignment and the fact that the pelvis is different, for example, clearly suggest that females are not simply “smaller males.”

Those differences, along with many others, may contribute to why women are more vulnerable than men in car crashes: the data shows that women are at far greater risk of suffering serious or fatal injuries in a collision compared to men.

In response to demand from safety engineers for superior tools to solve precisely  this problem, XSENSOR developed leading edge pressure imaging sensors that provide a level of high-speed impact data that’s never been available before now.

XSENSOR’S high speed pressure tools let engineers visualize the complete and precise interaction between passenger, seat, airbags and restraints in consistent and repeatable ways. If the goal is to make all people safer in a vehicle, these new insights mean improved passenger safety for everyone.

XSENSOR’S new platform of high-speed pressure imaging can be used in automotive impact testing for seats, airbags, seatbelts and child seats, as well as dynamic tire testing for speeds up to 150 km/h (93 mph).  With respect to seating, for instance, the impact system enables designers and safety evaluators to understand in a crash situation where the body makes contact with the seat, the effect of the pressures applied and what the consequences are for seat design.  XSENSOR’s ability to measure comfort, ingress and egress, vibration and transmissibility and the effect of both rear impact (whiplash) and front impact (seatbelts and airbags) in multiple accurate and repeatable ways is unparalleled.

It used to be that engineers relied on dummy sensors and data from high-speed cameras to determine what happened to passenger-dummies during a crash. With XSENSOR’s technology, you can see what’s happening to the subject on the seat surface, in unprecedented detail.

As XSENSOR COO Bruce Malkinson says, “For the first time, data shows how the subject compresses onto the surface and how the safety designs in the seat respond to the impact. The combination of the sensor properties, the data transmission rates, and the software functionality means that safety engineers can now see pressure images from the entire impact scenario at speeds that are similar to other measurement tools. Now pressure imaging provides pressure data that’s fast enough to visualize the impact of car seats, airbags and seatbelts.”

XSENSOR’s technology offers a new approach to the challenges of acquiring sufficient and qualified data in impact testing. With more than 3,000 sensing points on the back of a car seat alone, when whiplash testing using dummies of various sizes, for example, engineers get detailed maps of pressure impacts on the seat surface for each “person.” A superior ability to evaluate what parts of each dummy make contact with the seat, when, means automotive seat design that takes the safety of all bodies into account.