Torque-Tension Test Data Acquisition and Reduction

One of the functions of the Fastener Technical Section at GM Engineering Staff is to investigate the basic variables which affect fastener torque-tension relationships. The primary tool used for these investigations is the FTS Torque-Tension Test Machine. This machine has the capability of applying and measuring the torque to tighten, the resulting tension, the shank torque in the bolt, the number of degrees of rotation, and driver speed and air line pressure. In typical torque-tension testing, the tension in the fastener, the total tightening torque, and the torque in the bolt shank are measured using strain gaged load cells. In order to minimize test, and particularly, data reduction and analysis time, a computerized recording system is used. As a test is run, electrical signals from the load cells are stored and then automatically read into an IBM 1800 computer. The computer converts and analyses the data, computes statistics, and prints out a tabular and graphic summary of the data.