The authors proposed the quantitative criterion for the safety of ceiling boards in the preceding paper. In the ceiling drop tests, the impact load was measured by the load cell under the dummy head due to the measurement difficulty at the contact surface. Therefore, in this paper, the authors identified impact load on the contact surface, by inverse analysis, from the load cell record and validated it. As a result, it showed the impact load amplifies as the force transmits from the contact surface and the evaluation by the proposed criterion is on the safe side.
