Occupant Protection

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 can 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.

Front crash

• compliance with statutory and consumer-organization requirements , e.g. FMVSS208 5%ile HIII Dummy

Side crash

• compliance with statutory and consumer-organization requirements, such as IIHS SiD IIs

Rear crash

• compliance with statutory and consumer-organization requirements, e.g. EuroNCAP

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

Human Body Model

Until today, passive vehicle safety has been characterized by the use of crash test dummies (anthropomorphic test devices). In the future, the limitations associated with the design of crash test dummies are to be overcome by using human body models. These models are intended to take better consideration of the diversity of the human body in the development of vehicle restraint systems. The following factors can be taken into account: 

• weight and height
• gender
• age
• comfort seat positions

Pedestrian Safety

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.