SECTION 17 TILT TABLE ANALYSIS

Tilt Table Analysis What’s in this section: Tilt Table analysis Adams/Truck Plugin Setting up the analysis Inputs to the analysis

Tilt Table Analysis In this version of the Adams/Car-Truck Plugin we have included a tilt table analysis capability which is designed to help engineers determine the stability property of vehicles. The angle of inclination of the tilt table is increased either quasi-statically or dynamically and the simulation is terminated automatically (by a SENSOR) when tire vertical forces reach a user defined threshold value. This capability is supported for all Adams/Car full vehicle models provided that they are assembled with the tilt table test rig from the Truck plugin.

Tilt Table Analysis The Truck plugin includes a new testrig, .__TILT_TABLE_TESTRIG. This testrig allows static and dynamic tilt tests similar to those performed at many proving grounds. Typically these tests are used to estimate a vehicle's aggregate CG height and rollover point.

Adams/Car Truck Plugin Adams/Car provides the ‘Adams/Car Truck’ plugin which contains example models for a tractor semi-trailer as well as a bus. Different steering inputs will be applied to the tractor semi-trailer model to gauge the system response when inputs are close to the natural roll frequency of the vehicle system.

Setting-Up the Analysis To perform a tilt test simulation, you first must build a full-vehicle assembly referencing the new testrig .__TILT_TABLE_TESTRIG. The testrig includes joint primitives at each of the downhill wheels to prevent the vehicle from sliding off the table. These joints attach to the wheels automatically by use of communicators. The testrig is set up to attach to wheels from subsystems with the following minor roles: front, rear, rear_2, tag_axle, trailer_1, trailer_2. In this way the same testrig may be used with vehicle assemblies containing from two to six axles.

Inputs to the Analysis Below inputs are required for the Tilt Table analysis: Tilt rate (angle/time): Tilt table’s angular velocity. Maximum Angle: The tilt angle at which to stop the simulation. Force Sensor Threshold: The minimum tire force at which to stop the simulation. Move Right Side: Specify the direction of tilt.