Dynamic test fixture for a vehicle exhaust system capable of twelve DOF

摘要

A vehicle exhaust system test fixture integrates separate dynamic controls to provide at least twelve degrees of freedom (DOF). In one embodiment, two separate test tables are integrated so that one of the tables supports mounting of an engine/powertrain or apparatus simulating the engine/powertrain when coupled to an exhaust system. The other table supports mounting of the exhaust system to be tested. Each table is linked to a set of actuators/accelerometers to control motion up to 6 DOF. The capability of twelve DOF allows the test fixture to accurately reproduce both the dynamic behavior of a vehicle engine/powertrain during operation, and the dynamic behavior of the vehicle chassis during operation in the area where the exhaust system is attached to the vehicle frame. In addition, generated thermal profiles and high frequency external vibrations can be applied to allow simulation of real-world vibrations, and thermal stresses caused by hot exhaust gases. Another embodiment provides 12 DOF with a single test table rig arrangement. Yet another embodiment provides for greater than 12 DOF.