Vehicle dynamics is a fundamental part of vehicle performance.
It combines functional requirements (i.e. road safety) with emotional content (“fun to drive”, “comfort”): this balance is what characterizes the car manufacturer (OEM) driving DNA.
To reach the customer requirements on Ride & Handling, integration of CAE and testing is mandatory. Beside of cutting costs and time, simulation helps to break down vehicle requirements to component level.
On chassis, the damper is the most important component, contributing to define the character of the vehicle, and it is defined late, during tuning, mainly by experienced drivers. Usually 1D lookup tables Force vs. Velocity, generated from tests like the standard VDA, are not able to describe the full behavior of the damper: different dampers display the same Force vs. Velocity curve but they can give different feeling to the driver. Consequently, the capability to represent the full damper behavior, in testing and numerical simulation, is fundamental.
To do that, a new CAE damper model and an advanced testing protocol have been developed in collaboration between Hyundai Motor Group and Politecnico di Torino. The model has been developed in Matlab/Simulink® to be integrated with the CAE process used in HMETC (e.g. Driving Simulator).
It represents the damper behavior by the physics of its components (such as rod, valves components, etc.). Most of the parameters are sourced from damper BIM or by measuring them. The model has been verified against the output of the testing protocol, showing a good level of correlation up to 30 Hz.
The test protocol has been developed to provide more detailed informations about the damper force evolution under quasi-static and dynamic conditions.
A new way to analyze results in frequency domain has been proposed, to better understand, describe and correlate the damper performance to whole vehicle behavior.