ABSTRACT
For these applications, a torque-angle signature curve for tightening is recorded, then the parts are put in an environmental chamber and load/temperature cycled. Following the test load cycle the release angle signature is recorded. Analysis of the release angle signature in comparison to the tightening signature is used to directly estimate the percentage of initial clamp load lost due to embedment or creep of the plastic part in response to applied loads or
temperature cycles. By changing geometric shape and washer size, the effects can be quantitatively measured and compared.
