期刊名称：International Journal of Innovative Research in Science, Engineering and Technology
印刷版ISSN：2347-6710
电子版ISSN：2319-8753
出版年度：2015
期号：MULTICON
页码：1762
出版社：S&S Publications
摘要：Wave propagation based tools have found increasing application in the area of Structural HealthMonitoring. Wave propagation is a transient phase of dynamic response before the on-going wave and the in-comingwave superimpose over each other giving rise to a standing wave pattern. Whenever a wave encounters a changingimpedance (force per unit velocity), due to change of stiffness or mass, a reflecting wave is generated with the totalstrain energy forked as reflected as well as refracted portions. The ratio of reflected wave to the incident wave iscontrolled by the impedance change and hence the damage magnitude and position could be quantified. Hence wavepropagation mechanics comes in handy for damage detection and diagnosis. Dis-continuity (impedance mismatch) isinduced in the pile by varying its cross section area along its length. Analytical simulations are performed using theABAQUS on four different concrete piles under Pulse echo method. The effect of reduction of area (or increase ofarea) causes reduction in stiffness as well as mass and hence torsional impedance is not altered to a great extent. How awave propagation based technique is able to identify the location and magnitude of defect is brought out. The wavescattering denotes both wave reflection (coming back to the source) and wave refraction (going away from source).Damage identification under conditions of uniform wave propagation is an easier task as compared to dispersiveflexural wave propagation. The reason being that, until reflections from boundaries or damages are encountered thetime duration of the transient pulse is preserved and the response is quiescent. Hence the elapsed time and theamplitude of the reflected pulse can be a simple indicator of the location and magnitude of the damage respectively.This paper deals with torsional wave propagation in concrete pile with structural dis-continuities.
