This guest contribution is written by Jonathan Melvin Ph.D., Application Engineer, Active Human Models at Siemens Digital Industries Software (Tass International was recently acquired by Siemens DI SW), a member of the Altair Partner Alliance.
‘The Pull’ From Advances in the Automotive Industry
Simcenter Madymo crash simulation software is experiencing a revival, led by its Active Human Model.
The current rebirth of the electric car is recharging the entire automotive industry, providing designers with new challenges and opportunities:
- The smaller electric motors require different crash structure methodologies.
- The heavy batteries shift the location of the car’s center of mass and pose a risk of serious injury if they become damaged.
- A key selling point of an electric car is its range; therefore, an aerodynamic design is essential to reduce fuel use. The subsequent effect of this demand for fuel efficiency is that it necessitates changes in the cabin design.
New developments within the car industry are further fueled by the race to dominate the emerging driverless car market, with ever-increasing sensor, processing and connectivity capabilities. It is already possible to change lanes without touching the steering wheel and slow down to prevent an impact without touching the brake. All these features were once considered science fiction like KITT, David Hasselhoff’s car in Knight Rider.
Autonomous cars are no longer the dreams of 90’s action movie directors but are seemingly becoming more of a reality, with many automotive and tech companies investing in products like Simcenter PreScan* to develop the new technology. With these changes there are new unknowns for manufacturers: will the non-driving driver want to watch the road, read a book, surf the web or answer emails? This is just one of the questions designers are facing and this one alone opens a Pandora’s Box of questions for the designer of a safety system:
- If the driver and passengers are facing each other (conference seating), how do we prevent them from injuring each other in a collision?
- How does the seating direction change the loading of the occupants? And how do we make the pre-crash phase safer for occupants that are being loaded in opposite directions?
- Will these new loading scenarios cause rare injuries to become more common?
- Which seating position is safest in a crash?
- Should the seat be moved to a safer orientation/ position if a crash is imminent?
- If the driver is asleep, should they be woken up?
Simcenter MADYMO Has Fast Solutions
Each of these questions could take hundreds and thousands of simulations to answer. This demand to complete many tests as quickly as possible is the first reason Simcenter Madymo is seeing an increase in demand. If simulation speed is your prerequisite, then there is nothing that can match Madymo in the human injury simulation field. This has always been the case but with the new Madymo 7.8 release that has seen a complete overhaul and modernisation of the code, Simcenter Madymo is now even faster! The results from comparative studies are shown in the image below.
It is now common for safety systems to prepare for impact prior to a crash happening. One of the most commonly utilized pre-crash safety devices is the seat belt pretensioner. The pretensioner pulls the occupant back into the seat to ensure there is ample space for the airbag to detonate, fully expand, and begin to deflate before the occupant contacts it. With increased sensory capabilities and advanced control of the car, more of these pre-crash safety systems become possible, such as the repositioning car seat or the occupant consciousness status detection, mentioned previously.
‘The Push’ from The Active Human
These technology advances create two new problems for the designer that can be solved with Simcenter Madymo. First, the need to simulate pre-crash events makes the simulation time much longer. Traditional investigations that only look at the crash phase would need to simulate fractions of a second. Whereas, with pre-crash events included, the simulations can now be many seconds long. For complex systems, it can take many computer-hours to calculate a simulation of a few seconds using Simcenter Madymo. However, if the same simulation was done using an FE model, it would take much longer, including days or even weeks. Secondly, the Active Human model can respond to loads applied to it, such as lateral G, generated in a crash avoidance manoeuvre or a pre-crash braking phase, providing the designer with many more simulation possibilities.
The Active Human has also seen some recent updates such as its consciousness level. Using this feature, it is now possible to replicate drowsiness or unconsciousness. The updated Active Human also has a new shoulder with improved arm motion. The improved motion of the arm is particularly useful in pre-crash simulations where the driver is grasping the wheel.
The revival of Simcenter Madymo is, therefore, due to a renewed need for such a tool and the developments within Siemens. With updates and partnerships, Simcenter Madymo has more functionality (via its Active Human), is faster (owing to its new 7.8 release), and is compatible with more companion software packages, than ever before!
*Simcenter PreScan is not part of the Altair Partner Alliance