International Journal of Engineering Research and Technology. ISSN 0974-3154 Volume 6, Number 4 (2013), pp. 579-584 © International Research Publication House http://www.irphouse.com Investigation into Metal Wire Based Variant of EMI Technique for Structural Health Monitoring Susmita Naskar 1 and Suresh Bhalla 2 Department of Civil Engineering,Indian Institute of Technology Delhi. New Delhi-110016, India. E-mail: 1 susmita630000@gmail.com, 2 sbhalla@civil.iitd.ac.in. Abstract Electro mechanical impedance technique (EMI) is a newlyinvented non-destructive evaluation technique which is becoming very popular in the field of structural health monitoring.Nowadays the health monitoring issues for the case of composite building materials are getting more importance. In this article a new variant of EMI technique is proposed to effectively detect the initiation and progression of structural damage by the global dynamic electro-mechanicalimpedance (EMI) technique. In this context the PZT patches are used to acquire frequency electromechanical admittance signature to facilitate an improved damage assessment. The main problem of using EMI technique is the brittleness of the PZT patches. So to overcome from this problem this technique is approved by coupling a metal wire with a PZT element. The experiments were conducted on a bolted joint which connected two aluminium bars. In this method we created progressive damages and deterioration scenarios and evaluated with the application of the PZT patch metal wire EMI variant. Keywords: Structural health monitoring, PZT, Electromechanical impedance, compositematerial. 1. Introduction The process for implementing a damage identification strategy for civil, mechanical and aerospace engineering infrastructure is referred as Structural Health Monitoring (SHM).Though the mechanical and aerospace industry started to concentrate on the SHM aspects earlier, the civil engineering community had a little delayed start in this area. Civil engineers studied vibration-based damage assessment of bridge structures