The requirement for improved safety on the roads is reflected in the increasing legislation and higher consumer standards worldwide. Every new generation of vehicles new and more stringent statutory and other safety standards are introduced. Even before the first prototype vehicle is tested, CDH AG vehicle safety specialists are engaged early in the virtual design stage to ensure that such new safety standards will be satisfied.
For a wide range of vehicle crash scenario, the statutory and consumer standards require that sufficient post-crash space is available for the vehicle occupants. This results in various crash load cases.
- in compliance with statutory requirements of FMVSS208 and ECE R96
- in compliance with consumer-organization standards such as IIHS Small Overlap oder EuroNCAP Side Crash
- in compliance with statutory requirements of FMVSS214 and ECE R95
- in compliance with consumer-organization standards such as IIHS side crash oder EuroNCAP pillar impact
- in compliance with statutory requirements of FMVSS301
- in compliance with consumer-organization standards EuroNCAP Roll over
- in compliance with statutory requirements, e.g. Roof crush
Low speed crash cases such as bumper contact while parking are also addressed in the analysis load cases. This ensures that the vehicle structure is tolerant to minor impacts and that the associated repair costs, if any, are minimized.
Front- and rear crash
- For example, AZT, RCAR, Pendula
Through the application of crash simulation tools, CDH specialists can derive the best structural layout and characteristics for the body components, including dimensions material properties. To address the requirements of multiple vehicle functions, effective structural design requires the use of multiple discipline optimization tools at the various stages of design including:
- Abstract concept modelling
- Topology optimzation
- ody panel thickness optimization
- Robustness and reliability calculations
In structural design for occupant safety, focus is placed on the design of components with which the vehicle occupant could come into contact in the event of a collision. The performance of restraining systems such as airbag and seatbelts is of primary importance. However, components such as seats and dashboard are designed to reduce the possibility of injury to vehicle occupants.
The use of modern sensor equipment allows the instantaneous identity of crash severity. This is then factored with the physical characteristics of the passenger and the position of the seat to optimally trigger the air bag. Air bag control parameters can be included in the crash simulation calculations. By performing parameter studies in the computer, optimal characteristics for the air bag parameters such as gas-generator and seat belt force limiter can be found. The design of an optimal airbag system also requires that occupant out-of-position situations be simulated. The reliable prediction of restraining system behavior, requires the availability of mathematical models for the gas ignition process and the unfolding process of the packaged airbag.
compliance with statutory and consumer-organization requirements , e.g. FMVSS208 5%ile HIII Dummy
compliance with statutory and consumer-organization requirements, such as IIHS SiD IIs
compliance with statutory and consumer-organization requirements, e.g. FMVSS301
Because of the requirements for multiple design parameters and multiple load cases the use of automatic optimization tools is mandatory. Depending on the particular analysis discipline, one or more of the following methods are indicated:
- Design of Experiments(DoE)
- Gradient-based optimization methods
- Evolutionary Optimization algorithms
- Stochastic Optimization algorithms
In addition to the requirements for occupant safety, vehicle design criteria to reduce injuries to pedestrians in the event of contact have become increasingly important.
The potentially conflicting requirements of styling, space availability and safety can be addressed with the help of advanced analysis tools. Through simulation, solutions achievable by the use of new materials or the selection of active or passive safety devices can be examined in the early stages of vehicle design. In addition to offering its analysis services, CDH AG has long experience in the coordination of the testing activities that are necessary to provide material and correlation data for analysis. Our services for testing coordination include test-rig planning and comparisons between test and simulation results. We can also provide the project management communication and coordination services to ensure that the results of analysis and test activities are implemented in the vehicle design. The spectrum of CDH AG capabilities in this area includes the simulation and evaluation of the sensor signals that play an important role in pedestrian protection systems. The load cases addressed include:
- Head impact
- Hip Impact
- Leg impact
For each of the above laid cases, the statutory and consumer-organization requirements in Europe (EuroNCAP) and Japan (JapanNCAP) must be satisfied.