抄録
In the present study model photoelastic technique has been employed to determine dynamic stress distribution in a simply supported beam with over-hangs. The ratio of weight of the beam between supports and the weight of the striker was kept constant (2.675). A Fastax framing camera operating 12,000 frames per second has been employed to record the dynamic fringe photographs. Typical collision velocity of the striker was 1.6 m/s. Keeping the overall length of the urethane rubber beam (253 mm x 24.3 mm x 12.5 mm thick) as constant, the locations of the supports have been changed (for 90 mm, 120 mm and 150 mm spans) to generate different over-hang ratios. A freely rolling mass was employed to induce a low velocity impact at central and quarter spanlocations of the beam. The mass of the striker was varied between 10.5 to 17.5 gms. The contract force history generated by the impact was measured by using a suitable force transducer. Unfavourable boundary stress distribution for a beam span has been identified.
