Load Cell Training for the Students of Experimental Stress Analysis

Abstract

Many numerical models are nowadays available for the structural analysis of complexly shaped structures. However, a critical problem consists of the estimation of the actual loads that a structure withstands. The most proper way to determine them under service conditions consists of executing in-field tests, where load cells have an important role. This article deals with a didactic project at the University of Bologna, focused on the development of strain gage load cells, from design to calibration and use. Details are provided on the course units involved and on the levels of teaching, and three case studies are presented. Two case studies deal with the design of decoupled load cells, using simple beam geometry. Students had the opportunity to become confident with the principles of mechanics and to tackle the not trivial activities like calibration by decoupled load application and determination of the related matrices. The third one deals with the development of a load cell for impact loads, where the students had the chance to observe a practical application of the studied Wheatstone bridge connection, to participate in on-field tests, and to better understand the close relationship between experimentation and design.