【正文】
rameter two introduced the principle of the multipoint coordinated excitation modal test technology, the applicability of multipoint coordinated excitation modal test on secondary suspension vehicles, and established the pure modal criterion and modal purity indicating functions of secondary suspension vehicles at the same time, then conducted the simulation on secondary suspension vehicle by applying the multipoint coordinated excitation modal chapter three, taking the secondary suspension model car as the object, taking the multipoint coordinated excitation theory as the basis and the Labview as the piling platform, a multiinput and multioutput pure modal test system was developed. The system made an optimization design on the adjustable force interval of force signal via grid method