Strength Prediction of a Single Tooth Bound to Composite Pre-tightened Tooth Connection (PTTC) Joints based on Different Failure Criteria

Abstract

A method capable to predict the strength of single tooth bound to composite pre-tightened tooth connection (PTTC) joints is presented. The proposed method uses four representative failure criteria: max-stress, Tsai-Hill, Tsai-Wu and Hashin. The characteristic length method is also used to obtain prediction strengths. Three types of experiments of single PTTC joints were conducted using the following variations: 1) tooth depth, 2) tooth length, and 3) pre-tightened force. The experimental results were compared with the two-dimensional failure envelope diagram calculated using the four representative failure criteria. The physical nature and the strength predictive ability of each criterion were investigated. The obtained results show that the shear failure mode of single PTTC joint was accurately predicted by all four failure criteria. However, the Tsai-Wu criterion when compared to Maximum Stress, Tsai-Hill and Hashin criteria, exhibits better accuracy regarding the prediction strength of single PTTC joints, this is due to the fact that the Tsai-Wu criterion reflects more accurately the increase in the interlaminar shear strength caused by the transverse compressive stress.