ASA 126th Meeting Denver 1993 October 4-8

4pEA5. Response of steel beams with elastically restrained end conditions with and without cracks.

Shail R. Pandya Zhijing Wang Robert D. Finch

Dept. of Mech. Eng., Univ. of Houston, 4800 Calhoun Rd., Houston, TX 77204-4792

Ben H. Jansen

Univ. of Houston, Houston, TX 77204-4793

The vibration response of uniform and cracked beams with elastically restrained end conditions under impact excitation is being experimentally investigated. Preliminary work has revealed that the response obtained does not match that predicted theoretically for pinned--pinned end conditions. In practice, most beams have nonclassical end conditions as a certain amount of flexibility is unavoidable. Therefore a theory of vibration of beams with elastically restrained end conditions was applied. The results of this theory were in close agreement with the response obtained from beams mounted on elastic supports. An antiresonance for the pinned--pinned beam has been found for the fifth mode of vibration whose frequency matches the natural frequency of the supports. Cracks simulated by slots are currently being made at various locations along the length of the beam. The impact response of these slotted beams will also be reported and comparisons will be made between the theoretical and the experimental results. [Work supported by NSF Grant No. MSS-9024224.]