Los Alamos National LaboratoryEngineering Institute
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Remote Inspection of Bolted Joints using Piezoelectric Sensors and RFID-Tagged Communication

Collaboration between Los Alamos National Laboratory and the University of California at San Diego (UCSD) Jacobs School of Engineering


  • Institute Director
  • Charles Farrar
  • (505) 663-5330
  • Email
  • UCSD EI Director
  • Michael Todd
  • (858) 534-5951
  • Executive Administrator
  • Ellie Vigil
  • (505) 667-2818
  • Email
  • Institute Administrator
  • Vacant

UCSD Faculty and Graduate Students

  • Professor Michael Todd , Structural Engineering
  • Professor Douglas Palmer, Cal it^2

LANL Collaborators

  • Dr. Gyuhae Park (INST-OFF: INSTITUTES)

The proposed task seeks to create smart structural bolted connections in order to significantly reduce resources that are dedicated to inspection routines of joint connections. A “smart connection” consists of structural members joined together by bolt and nut combinations equipped with piezoelectric (PZT) sensing elements and RFID (Radio Frequency Identification) tags for communications. Together, these elements can be used for the remote and rapid inspection of bolt tension and connection damage without external power sources. 
In this task, PZT (or other dielectric) enhanced washers will be used to continuously monitor the condition of the joint by monitoring its dynamic characteristics.  A comprehensive study will be performed to correlate the changes in the preload with the capacitive value of PZT enhanced washers.  The mechanical impedance matching between the sensing devices and the joint connections will be used as a key feature to monitor the preload changes and prevent further failure. The rapid inspection of this joint can be made with an integration of an LC circuit in RFID-tagged sensor systems.  Further development of the connection mechanics and modeling of damage modes and PZT enhanced washers are required to realize this useful tool.  Both theoretical modeling and experimental verification are proposed with a goal of providing an effective means of remote inspection of critical bolted joints.