Abstract
Steering columns for column assist Electric Steering are one of the main elements of the passive safety restraint system in a passenger vehicle. It is designed to collapse applying an optimized ride down force to reduce chest and head injuries of the driver during a frontal crash event, making this requirement one of the most important ones for its development. The system crash response is generated by several elements and interfaces due to the fact of many other different product requirements that a steering column must fulfill. This could lead into a complex validation process throughout the development, as it is needed to integrate the product into the vehicle in order to meet the passive safety requirements. As part of ZF lean Validation approach a new method has been developed to improve the system robustness in ZF Active safety division by means of virtual simulation and six sigma disciplines. This resultant method is also applicable for a model based development process and also contributes to improve frontloading development techniques. An analysis of variance has been done using a correlated virtual model for crash simulation, where the main parameters of the system are known (normally the case when same product generation is reused in a new vehicle). Obtaining as a result of the analysis the regression equation of the system response. This equation defines and quantifies the importance of each factor, and consequently is defining the component contribution and how to develop a column from bottom to top. Moreover, as a second step, a Monte Carlo analysis has been applied using the equation obtained generating statistical results for a number of cases (based in the design tolerances) not manageable from the hardware testing perspective neither from the finite elements methods. In that project Monte Carlo analysis has been applied for 100,000 cases generating response confident intervals instead of the classic FEM deterministic response where only the nominal case is considered.
Highlights
Powered steering column drive (EPS-CD) is a technology used to provide assist torque, as well as new steering features, for A to D segment vehicles
That number might not be enough to cover the variability from a production of hundreds of thousand parts per year like in the case of an Electrically powered steering column drive (EPS-CD) product
Monte Carlo simulation In that step we have already concluded the work on the field of finite elements methods, we have obtained from it a proper understanding of the system and a tool to evaluate the contribution of each factor in order to generate a polynomial equations in function of the main parameters
Summary
Powered steering column drive (EPS-CD) is a technology used to provide assist torque, as well as new steering features, for A to D segment vehicles. The steering column crash response is normally generated by several elements and interfaces, where many of them have requirements in other functionalities in addition to passive safety. A Monte Carlo simulation had been applied using the equation obtained generating statistical results for a number of cases (based in the design tolerances) not manageable from the hardware testing perspective, neither from the finite elements methods. The Monte Carlo simulation has been applied for 100,000 load cases generating probabilistic response instead of “deterministic response” (one geometry, one result) With these two steps we have been able to create the manufacturing variability response for a destructive test in a highly cost and time effective approach. As part of the democratization, the equation can be used during the requirement elicitation phase with customers generating confidence in the acceptance criteria
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Advanced Modeling and Simulation in Engineering Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
