Impact Response Evaluation of Force Transducer for Use in Falling Weight Deflectometer System

摘要

The impact response of a force transducer in a falling weight deflectometer system is evaluated by an optical method. In the method, a mass is made to collide with a force transducer and the impact force is measured highly accurately as the inertial force acting on the mass. A pneumatic linear bearing is used to realize linear motion with a sufficiently small friction acting on the mass, i.e., the moving part of the bearing. The method is an improved variation of the Levitation Mass Method, which has been proposed and developed by the first author. The impact force, which has a maximum value of approximately 1.66 kN and a full width at half maximum of approximately 5.0 ms, has been applied and measured using the Levitation Mass Method with the standard uncertainty of approximately 3.3u000210 N. This corresponds to 2u000210-2 (2%) of the maximum applied force in the experiments. The present status of the method and the points to be considered for the future improvements are discussed.