Finite element analysis for evaluating the effect of repeated impact in the impact test of spacer grid

Impact tests are conducted to evaluate the impact characteristics and resistance of the spacer grid. The lateral impacts are applied to the grid specimen with increasing the height or angle of hammer. The grid specimen is very expensive due to the material and welding cost, and thus the impact test in which the impact loads are applied to one specimen repeatedly has been conducted. In this paper, the effects of repeated impact on the impact force are evaluated by giving the lateral impact two or three times to the 5 x 5 partial spacer grid specimen. The finite element analysis is made to simulate the repeated impact test, and the reduction of impact force by the repeated impact is predicted and compared with the test results