Factors affecting bolt bearing surface effective radius

A calculation scheme for the factors affecting bearing surface effective radius is proposed to gain the accurate torque-tension relationship. The bolted joint parametric model with thread feature is established by ANSYS parametric design language commend stream. The pressure distribution on the connected plant junction surface is revealed by I-Scan pressure-sensitive films. Compared with the finite element analysis, the reliability of parametric model is verified. Then the bolt bearing surface effective radius is calculated by the measured pressure distributions. It is found that the bolt bearing surface effective radius extends with increasing preload and clear, and reduces with increasing plate thickness and its elastic modulus, while bolt pitch has little effect on the effective radius.